WO2024118220A1

WO2024118220A1 - Glass article having plasma treated edge, method of treating the edge with plasma, and system to perform the method

Info

Publication number: WO2024118220A1
Application number: PCT/US2023/037187
Authority: WO
Inventors: Li-Wei Chou; Jiangwei Feng; Kuan-Ting Kuo; Min-Woo Lee; Jhih-Wei LIANG; Bruce Warren Reding; Hsuan-Yu Teng; Bingpeng WANG; Junjie Zhao
Original assignee: Corning Inc
Current assignee: Corning Inc
Priority date: 2022-11-29
Filing date: 2023-11-13
Publication date: 2024-06-06
Anticipated expiration: 2025-05-29
Also published as: CN118108429A; KR20240081390A

Abstract

A method of treating a glass article includes (i) contacting an edge of a glass article with an atmospheric-pressure plasma generated from gas while moving at least one of the glass article and the atmospheric-pressure plasma relative to the other; and (ii) imparting additional heat to one or both of a first primary surface and a second primary surface proximate the edge of the glass article simultaneously with contacting the edge of the glass article with the atmospheric-pressure plasma. The resulting glass article exhibits (i) a surface roughness (Ra) within a range of from 30 nm to 110 nm, (ii) a low density of particles upon the edge, and (iii) a residual stress at or near the edge that has a maximum deviation from 0 that is within a range of from -100 MPa to 40 MPa, where negative values are compressive stress and positive values are tensile stress.

Description

GLASS ARTICLE HAVING PLASMA TREATED EDGE, METHOD OF TREATING THE EDGE WITH PLASMA, AND SYSTEM TO PERFORM THE METHOD

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority under 35 U.S.C. § 119 of Chinese Patent Application Serial No. 202211512365.3 filed on November 29, 2022, the content of which is relied upon and incorporated herein by reference in its entirety.

FIELD OF THE DISCLOSURE

[0002] The present disclosure generally relates to a glass article with an edge that has been treated with atmospheric-pressure plasma.

BACKGROUND

[0003] Glass articles are utilized in a variety of products to cover displays. For example, a glass article is sometimes incorporated into an interior of a vehicle to cover a display located at a dashboard. As another example, a glass article is sometimes incorporated into a personal electronic device to cover a display. The glass article is sometimes cut to shape, which creates an edge. The glass article is sometimes chemically tempered to generate a region of compressive stress that generally increases the impact and scratch resistance of the glass article.

[0004] However, there is a problem in that an edge of the glass article can have (i) inwardly extending flaws that reduce flexural strength of the glass article or (ii) a profile with suboptimal smoothness or debris that diminishes transparency and perceived quality.

SUMMARY

[0005] The present disclosure addresses that problem with treating an edge of a glass article with atmospheric-pressure plasma simultaneously with imparting additional heat near the edge of the glass article. The plasma treatment eliminates or reduces flaws and rounds the geometry of remaining flaws. The plasma treatment reduces the surface roughness (Ro) of the edge and renders the edge highly transparent. The plasma treatment leaves a low density of particles on the edge. The simultaneous addition of heat to the glass article near the edge generates a residual stress at the edge that is compressive or neutral, allowing for high speed of translation of the edge relative to the plasma treatment, without causing a residual tensile stress to develop, which may lead to self-fracture of the glass article. The compressive residual stress improves the bend strength of the glass article. The glass article need not be annealed to relieve residual tensile stress. The glass article can be subsequently ion- exchanged, which further increases the bend strength of the glass article. The number of, and direction of, heads that emit the plasma can be manipulated to generate chamfer portions contiguous with the edge, or to generate chamfer portions with an entirely cured edge. The head may have an arc-shaped slot into which the edge of the glass article can be slotted to further refine plasma flow and edge shape after plasma treatment.

[0006] In a first aspect of the present disclosure, a glass article comprises: (1) a first primary surface; (2) a second primary surface that faces in a generally opposite direction than the first primary surface; (3) a thickness between the first primary surface and the second primary surface that is within a range of from 0.095 mm to 3.5 mm; and (4) an edge transitioning the first primary surface to the second primary surface; wherein (a) the edge exhibits a surface roughness (Ro) within a range of from 30 nm to 110 nm, (b) a density of particles upon the edge is less than 2 particles per 0.1 square millimeter, (c) the glass article exhibits a residual stress at or near the edge that has a maximum deviation from 0 that is within a range of from -100 MPa to 40 MPa, where negative values are compressive stress and positive values are tensile stress, and (d) one of the following conditions are satisfied: (i) the glass article further comprises one or more regions of compressive stress contiguous with one or more of the first primary surface and the second primary surface, and upon being subjected to a four-point flexural test according to ASTM C158, the glass article exhibits a BIO Weibull distribution flexural stress value within a range of from 700 MPa to 900 MPa; or (ii) the glass article lacks a region of compressive stress, and upon being subjected to the four-point flexural test according to ASTM C158, the glass article exhibits a B10 Weibull distribution flexural stress value that is greater than or equal to 300 MPa.

[0007] According to a second aspect of the present disclosure, the glass article of the first aspect further comprises: one or more regions of compressive stress contiguous with one or more of the first primary surface and the second primary surface, wherein, upon being subjected to the four-point flexural test according to ASTM C158, the glass article exhibits a BIO Weibull distribution flexural stress value within a range of from 700 MPa to 900 MPa.

[0008] According to a third aspect of the present disclosure, the glass article of the first aspect is presented, wherein (i) the glass article lacks a region of compressive stress, and (ii) upon being subjected to the four-point flexural test according to ASTM C158, the glass article exhibits a BIO Weibull distribution flexural stress value that is greater than or equal to 300 MPa.

[0009] According to a fourth aspect of the present disclosure, the glass article of any one of the first through third aspects is presented, wherein the first primary surface and the second primary surface each comprise a non-planar portion.

[0010] According to a fifth aspect of the present disclosure, the glass article of any one of the first through fourth aspects is presented, wherein the glass article is a component of an interior of a vehicle or a consumer electronic device.

[0011] According to a sixth aspect of the present disclosure, the glass article of any one of the first through fifth aspects is presented, wherein the glass article is selected from the group consisting of: a borosilicate glass, an alumino boro silicate alkali-free glass, an aluminoborosilicate glass, an alkaline earth aluminoborosilicate glass, high purity fused silica, an alkali-containing glass, a glass that includes one or more rare earth oxides, a non-silicate glass, a borate glass, a boroaluminate glass, a phosphate glass, a germanate glass, a fluorophosphate glass, a sulfophosphate glass, a vanadate glass, and a glass-ceramic.

[0012] According to a seventh aspect of the present disclosure, the glass article of any one of the first through sixth aspects further comprises: a chamfer portion transitioning between the edge and the first primary surface.

[0013] According to an eighth aspect of the present disclosure, the glass article of any one of the first through sixth aspects is presented, wherein the edge provides an entirely curved transition from the first primary surface to the second primary surface.

[0014] According to a ninth aspect of the present disclosure, the glass article of any one of the first through eighth aspects is presented, wherein (i) the maximum deviation from 0 of the residual stress at or near the edge is disposed at a position within the glass article that is within 1000 pm from the edge, and (ii) the residual stress within the glass article at positions 1800 pm from the edge and further into the glass article is within a range of from -5 MPa to 5 MPa.

[0015] According to a tenth aspect of the present disclosure, the glass article of any one of the first through ninth aspects is presented, wherein the residual stress at the edge and to a distance of at least 100 pm into the glass article from the edge is compressive.

[0016] According to an eleventh aspect of the present disclosure, the glass article of any one of the first through tenth aspects is presented, wherein (i) the residual stress as a function of distance from the edge into the glass article has a slope, (ii) at least a portion of the slope has an absolute value of 0.2 MPa/pm or greater, and (iii) the portion of the slope is directed towards greater compressive stress.

[0017] According to a twelfth aspect of the present disclosure, the glass article of the eleventh aspect is presented, wherein the portion of the slope occurs within 100 pm into the glass article from the edge.

[0018] According to a thirteenth aspect of the present disclosure, the glass article of any one of the first through twelfth aspects is presented, wherein a number of atoms per volume of one or more of Mg, Ca, Al, and Sr is substantially constant at all positions within the glass article from 30 nm from the edge to 200 nm from the edge.

[0019] According to a fourteenth aspect of the present disclosure, the glass article of any one of the first through thirteenth aspects is presented, wherein the glass article exhibits a residual stress at or near the edge that has a maximum deviation from 0 that is within a range of from -70 MPa to -20 MPa, where negative values are compressive stress.

[0020] According to a fifteenth aspect of the present disclosure, the glass article of any one of the first through fourteenth aspects is presented, wherein the glass article has not been subjected to an annealing procedure.

[0021] According to a sixteenth aspect of the present disclosure, a method of treating a glass article comprises: (a) contacting an edge of a glass article with an atmospheric-pressure plasma generated from gas while moving at least one of the glass article and the atmospheric- pressure plasma relative to the other; and (b) imparting additional heat to one or both of a first primary surface and a second primary surface proximate the edge of the glass article simultaneously with contacting the edge of the glass article with the atmospheric-pressure plasma.

[0022] According to a seventeenth aspect of the present disclosure, the method of the sixteenth aspect further comprises: before contacting the edge of the glass article with the atmospheric-pressure plasma, grinding or laser-cutting the edge.

[0023] According to an eighteenth aspect of the present disclosure, the method of any one of the sixteenth through seventeenth aspects further comprises: after contacting the edge with the atmospheric-pressure plasma, subjecting the glass article to an ion-exchange procedure resulting in one or more regions of compressive stress within the glass article. [0024] According to a nineteenth aspect of the present disclosure, the method of the eighteenth aspect of the present disclosure is presented, wherein after the edge of the glass article is contacted with the atmospheric-pressure plasma and after subjecting the glass article to the ion-exchange procedure, upon being subjected to the four-point flexural test according to ASTM C158, the glass article exhibits a BIO Weibull distribution flexural stress value within a range of from 700 MPa to 900 MPa.

[0025] According to a twentieth aspect of the present disclosure, the method of any one of the sixteenth through nineteenth aspect is presented, wherein after the edge of the glass article is contacted with the atmospheric-pressure plasma, upon being subjected to a four- point flexural test according to ASTM C158, the glass article exhibits a B10 Weibull distribution flexural stress value that is greater than or equal to 300 MPa.

[0026] According to a twenty-first aspect of the present disclosure, the method of any one of the sixteenth through twentieth aspects is presented, wherein a laser, a heat lamp, or a second atmospheric-pressure plasma is utilized to impart the additional heat.

[0027] According to a twenty-second aspect of the present disclosure, the method of any one of the sixteenth through twenty-first aspects is presented, wherein after contacting the edge with the atmospheric-pressure plasma and after imparting the additional heat to the glass article, the glass article exhibits a residual compressive stress at or near the edge that has a maximum deviation from 0 that is within a range of from -80 MPa to 40 MPa, where negative values are compressive stress and positive values are tensile stress.

[0028] According to a twenty-third aspect of the present disclosure, the method of any one of the sixteenth through twenty-second aspects is presented, wherein the atmospheric- pressure plasma is generated from one or more of nitrogen gas, compressed dry air gas, helium gas, argon gas, and hydrogen gas.

[0029] According to a twenty-fourth aspect of the present disclosure, the method of any one of the sixteenth through twenty-third aspects is presented, wherein the atmospheric- pressure plasma contacts the edge at an angle other than perpendicular to the edge.

[0030] According to a twenty-fifth aspect of the present disclosure, the method of any one of the sixteenth through twenty-fourth aspects is presented, wherein contacting the edge of the glass article with the atmospheric-pressure plasma generates a first chamfer portion that transitions the edge to the first primary surface. [0031] According to a twenty-sixth aspect of the present disclosure, the method of any one of the sixteenth through twenty-fourth aspects is presented, wherein contacting the edge of the glass article with the atmospheric-pressure plasma generates (i) a first chamfer portion that transitions the edge to the first primary surface and (ii) a second chamfer portion that transitions the edge to the second primary surface.

[0032] According to a twenty-seventh aspect of the present disclosure, the method of any one of the sixteenth through twenty-sixth aspects is presented, wherein contacting the edge of the glass article with the atmospheric-pressure plasma generates a curved surface at the edge.

[0033] According to a twenty-eighth aspect of the present disclosure, the method of any one of the sixteenth through twenty-seventh aspects is presented, wherein contacting the edge of the glass article with the atmospheric-pressure plasma comprises simultaneously contacting the edge with more than one atmospheric-pressure plasma such that heat generated by any two adjacent plasma jets at least partially overlaps.

[0034] According to a twenty-ninth aspect of the present disclosure, the method of any one of the sixteenth through twenty-eighth aspects is presented, wherein the first primary surface and the second primary surface each comprise a non-planar portion.

[0035] According to a thirtieth aspect of the present disclosure, the method of any one of the sixteenth through twenty-ninth aspects is presented, wherein the glass article is selected from the group consisting of: a borosilicate glass, an alumino boro silicate alkali-free glass, an aluminoborosilicate glass, an alkaline earth aluminoborosilicate glass, high purity fused silica, an alkali-containing glass, a glass that includes one or more rare earth oxides, a non-silicate glass, a borate glass, a boroaluminate glass, a phosphate glass, a germanate glass, a fluorophosphate glass, a sulfophosphate glass, a vanadate glass, and a glass-ceramic.

[0036] According to a thirty-first aspect of the present disclosure, the method of any one of the sixteenth through thirtieth aspects is presented, wherein after contacting the edge with the atmospheric-pressure plasma and after imparting the additional heat to the to the glass article, the edge exhibits a surface roughness (Ro) within a range of from 30 nm to 110 nm.

[0037] According to a thirty-second aspect of the present disclosure, the method of any one of the sixteenth through thirty-first aspects is presented, wherein (i) after contacting the edge with the atmospheric-pressure plasma and after imparting the additional heat to the to the glass article, the glass article further comprises particles upon the edge, and (ii) a density of the particles upon the edge is less than 2 particles per 0.1 square millimeter.

[0038] According to thirty-third aspect of the present disclosure, the method of any one of the sixteenth through thirty-second aspects is presented, wherein the glass article comprises a thickness that is within a range of from 0.095 mm to 3.5 mm.

[0039] According to a thirty-fourth aspect of the present disclosure, the method of any one of the sixteenth through thirty-third aspects is presented, wherein the at least one of the glass article and the atmospheric-pressure plasma moves relative to the other at a speed within a range of from 20 mm/second to 200 mm/second.

[0040] According to a thirty-fifth aspect of the present disclosure, the method of any one of the sixteenth through thirty-third aspects is presented, wherein the at least one of the glass article and the atmospheric-pressure plasma moves relative to the other at a speed that is greater than or equal to 20 mm/second.

[0041] According to a thirty-sixth aspect of the present disclosure, the method of any one of the sixteenth through thirty-fifth aspects is presented, wherein the glass article is not subjected to an annealing procedure, after contacting the edge with the atmospheric- pressure plasma and imparting additional heat to one or both of the first primary surface and a second primary surface proximate the edge.

[0042] According to a thirty-seventh aspect of the present disclosure, the method of any one of the sixteenth through thirty-sixth aspects is presented, wherein imparting the additional heat to one or both of the first primary surface and the second primary surface proximate the edge simultaneously with contacting the edge of the glass article with the atmospheric- pressure plasma causes the residual tensile stress at or near the edge to transition to no residual stress or residual compressive stress.

[0043] According to a thirty-eighth aspect of the present disclosure, a system to treat an edge of a glass article comprises: (a) a support configured to support a glass article that has an edge; and (b) a first head configured and positioned to emit atmospheric-pressure plasma onto the edge of the glass article; wherein, one or both of the support and the first head are movable relative to the other.

[0044] According to a thirty-ninth aspect of the present disclosure, the system of the thirtyeighth aspect further comprises: a second head configured and positioned to emit atmospheric-pressure plasma onto the edge of the glass article, with the heat of the plasma from the first head at least partially overlapping the heat of the plasma from the second head. [0045] According to a fortieth aspect of the present disclosure, the system of any one of the thirty-eighth through thirty-ninth aspects further comprises: one or more heat emitters positioned relative to the support to emit heat onto one or both of a first primary surface and second primary surface of the glass article near where the first heat emits plasma onto the edge of the glass article.

[0046] According to a forty-first aspect of the present disclosure, the fortieth aspect is presented, wherein the one or more heat emitters comprise one or more of a laser source, a lamp, or a head configured to emit atmospheric-pressure plasma.

[0047] According to a forty-second aspect of the present disclosure, the system of any one of the thirty-eighth through forty-first aspects is presented, wherein the first head is positioned relative to the support to emit plasma generally orthogonal to the edge of the glass article. [0048] According to a forty-third aspect of the present disclosure, the system of any one the thirty-eighth through forty-first aspects is presented, wherein the first head is positioned relative to the support to emit plasma at an angle between (i) orthogonal to a first primary surface of the glass article and (ii) orthogonal to the edge of the glass article.

[0049] According to a forty-fourth aspect of the present disclosure, the system of any one of the thirty-eighth through forty-third aspects is presented, wherein the first head comprises (i) a slot configured to accept the edge of the glass article and (ii) a plurality of apertures at the slot positioned to emit plasma onto at least two of a first primary surface of the glass article, the edge of the glass article, and a second primary surface of the glass article.

[0050] According to a forty-fifth aspect of the present disclosure, the system of the fortyfourth aspect is presented, wherein the slot of the first head is arc-shaped.

[0051] According to a forty-sixth aspect of the present disclosure, the system of any one of the thirty-eighth through forty-fifth aspects is presented, wherein one or both of the support and the first atmospheric-pressure plasma emitter are movable relative to the other at a rate that is greater than or equal to 20 mm/second.

BRIEF DESCRIPTION OF THE DRAWINGS

[0052] In the figures:

[0053] FIG. 1 is a perspective view of a glass article of the present disclosure, illustrating the glass article including an edge; [0054] FIG. 2 is an elevational view of a cross-section of the glass article of FIG. 1, illustrating the glass article including regions of compressive stress contiguous with a first primary surface and a second primary surface;

[0055] FIG. 3A is a schematic overhead view of the glass article of FIG. 1 undergoing a four- point flexural test according to ASTM C158 to determine a flexural test of the glass article;

[0056] FIG. 3B is a schematic elevational view of the test fixture for the four-point flexural test according to ASTM C158 of FIG. 3A;

[0057] FIG. 4 is a perspective view of embodiments of the glass article of FIG. 1, illustrating the glass article as having a planar portion and a non-planar portion;

[0058] FIG. 5A is a perspective view of an interior of a vehicle including the embodiments of the glass article of FIG. 4, illustrating the glass article covering displays at a dashboard;

[0059] FIG. 5B is an overhead view of the glass article of FIG. 1 as a component of an electronic device, illustrating the glass article covering a display;

[0060] FIG. 6 is an elevational close-up view of the edge of embodiments of the glass article of FIG. 1, illustrating a first chamfer portion transitioning the edge to the first primary surface; [0061] FIG. 7 is an elevational close-up view of the edge of embodiments of the glass article of FIG. 1, illustrating the edge providing an entirely curved surface;

[0062] FIG. 8 is a flow chart of a method of forming the glass article of FIG. 1, illustrating a step of treating the edge of the glass article with an atmospheric-pressure plasma;

[0063] FIG. 9 is a perspective view of the plasma treatment step of the method of FIG. 8, illustrating a head emitting the plasma directed to the edge while the glass article moves relative to the head;

[0064] FIG. 10 is an elevational view of embodiments of the plasma treatment step of FIG. 9, illustrating the head directing the plasma toward the edge at an angle tilted toward the first primary surface and generating the first chamfer portion;

[0065] FIG. 11 is an elevational view of embodiments of the plasma treatment step of FIG. 9, illustrating a first head directing plasma toward the edge tilted toward the first primary surface and a second head directing plasma toward the edge tilted toward the second primary surface;

[0066] FIG. 12A is a perspective view of embodiments of another step of the method of FIG.

8 that imparts additional heat to the glass article while the plasma treatment step is occurring; [0067] FIG. 12B are schematic diagrams of (a) a representative temperature gradient within the glass article from the edge if no additional heat is imparted to the glass article, (b) a representative temperature gradient if additional heat is imparted to the glass article at a position before plasma contacts the edge, and (c) a representative temperature gradient if additional heat is imparted to the glass article at a position after plasma contacts the edge, illustrating in cases (b) and (c) that the additional heat flattens the temperature gradient compared to case (a);

[0068] FIG. 13A is a perspective view of grinding wheels grinding the edge, according to a grinding or laser cutting step of the method of FIG. 8;

[0069] FIG. 13B is a perspective view of a laser source directing a laser beam onto a workpiece to separate the glass article from the workpiece;

[0070] FIG. 14 is a perspective view of a system of the present disclosure to effectuate the plasma treatment step of FIG. 9 of the method of FIG. 8, illustrating a support to secure the glass article while the glass article moves relative to the head that emits plasma;

[0071] FIG. 15 is an elevational view of embodiments of the head of the system of FIG. 14, illustrating the head having (i) a slot within which the edge of the glass article is disposed and (ii) apertures distributed around the slot to direct plasma to different portions of the edge;

[0072] FIG. 16, pertaining to Example 1, reproduces scanning electron microscope and optical microscope images of non-plasma finished edges (Samples 1A1, 1A2, 1B1, 1B2) and a plasma finished edge (Samples 1A3, 1B3), illustrating the plasma finished edge having a more visibly smooth surface and a lower surface roughness (Ro);

[0073] FIG. 17, pertaining to Example 1, reproduces Weibull distribution plots for the edge strength of non-plasma finished edges (Samples 1A2) and plasma finished edges (Samples 1A3), illustrating that the plasma finished edges had greater edge strength than the non- plasma finished edges;

[0074] FIG. 18, pertaining to Example 1, reproduces Weibull distribution plots for the edge strength of non-plasma finished edges (Samples 1B1) and plasma finished edges (Samples 1B2 and 1B3), illustrating that the plasma finished edges had greater edge strength than the non- plasma finished edges;

[0075] FIG. 19, pertaining to Example 2, reproduces optical microscope images of non-plasma treated edges (Samples 2A and 2B) and a plasma treated edge (Sample 2C), illustrating that the sample with the plasma treated edge had a more visibly smooth edge and a lower surface roughness (Ro) than the samples with the non-plasma treated edge;

[0076] FIG. 20, pertaining to Example 3, reproduces scanning electron microscope and optical microscope images of Sample 3A where a grinding wheel created chamfer portions and finished the edge and Samples 3B and 3C where a plasma treatment created the chamfer portions and finished the edge, illustrating the plasma treatment can create chamfer portions and provides a visually smooth surface;

[0077] FIG. 21A, pertaining to Example 4, provides a temperature profile as a function of distance from the edge after treatment with plasma (generated from nitrogen and argon gas) and time since plasma treatment, a Polsope image of the plasma treated edge, and residual stress as a function of distance from the edge, illustrating that a relatively steep temperature gradient was generated and a residual tensile stress profile was produced;

[0078] FIG. 21B, pertaining to Example 4, provides the same information as FIG. 22A but after treatment with plasma generated from nitrogen, argon, and hydrogen gasses, illustrating that the treatment with plasma generated from the more highly conductive hydrogen gas generated a flatter temperature gradient and a residual compressive stress profile was generated;

[0079] FIG. 22, pertaining to Example 5, is a graph that plots scan speed as a function of residual stress at or near the edge for samples using plasma generated from different gasses, illustrating that the propensity to generate residual tensile stress increases as scan speed increases, the scan speed being the rate at which the edge moves relative to the plasma;

[0080] FIG. 23, pertaining to Example 6, reproduces temperature profiles generated via a computation model where the plasma is directed orthogonally to the edge (left profile) and where the plasma is directed to the edge at an angle trailing or leading the movement of the edge relative to the plasma (right profile);

[0081] FIG. 24, pertaining to Example 7, provides schematic diagrams for positioning of the head relative to the edge during a plasma treatment and a graph that plots resulting edge stress as a function of position from the edge, illustrating that plasma treatment generated a spike in compressive stress from the edge and into the glass article less than 500 pm from the edge, and the stress levels out to near zero by 1500 pm into the glass article from the edge;

[0082] FIG. 25A, pertaining to Example 8, reproduces graphs that plot atomic density as a function of position from the edge for various elements after a plasma treatment occurred using plasma partially generated from hydrogen, illustrating that plasma generated in part from hydrogen causes very little change in the composition at or near the edge;

[0083] FIG. 25B, pertaining to Example 8, reproduces graphs that plot atomic density as a function of position from the edge for various elements after a plasma treatment occurred using plasma partially generated from helium;

[0084] FIG. 26, pertaining to Example 9, reproduces images of a sample glass article with a thickness of less than 0.1 mm with an edge not treated to remove imperfections (left images) and a sample glass article with a thickness of less than 0.1 mm with an edge treated via atmospheric-pressure plasma to remove or less such imperfections;

[0085] FIG. 27A, pertaining to Example 10, reproduces scanning electron microscope images of edges of samples having a thickness of 0.1 mm, including a Sample 10A (top left) not having been plasma treated, a Sample 10B (top right) having been plasma treated, and Sample 10C (bottom) also having been plasma treated, illustrating the plasma edges having much less surface roughness and imperfections than then untreated edge; and

[0086] FIG. 27B, pertaining to Example 10, reproduces Weibull distribution plots for the two- point edge strength of a Sample 10A with a non-plasma finished edge and Samples 10B-10E having plasma finished edges, illustrating that the plasma finished edges had greater edge strength than the non-plasma finished edges.

DETAILED DESCRIPTION

[0087] Referring now to FIG. 1, a glass article 10 of the present disclosure includes a first primary surface 12, a second primary surface 14, and an edge 16. The first primary surface 12 generally faces in a direction 18. The second primary surface 14 generally faces in a direction 20, which is generally opposite of the direction 18 that the first primary surface 12 faces. The edge 16 transitions the first primary surface 12 to the second primary surface 14. The edge 16 provides the minor surface of the glass article 10.

[0088] The glass article 10 has a thickness 22. The thickness 22 is the straight-line distance between the first primary surface 12 and the second primary surface 14 measured orthogonally to the first primary surface 12 at any given point on the first primary surface 12. The thickness 22 can be measured with a micrometer. In embodiments, the thickness 22 is within a range of from 0.095 mm to 3.5 mm. In embodiments, the thickness 22 is 0.095 mm, 0.1 mm, 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2.0 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, 2.5 mm, 2.6 mm, 2.7 mm, 2.8 mm, 2.9 mm, 3.0 mm, 3.1 mm, 3.2 mm, 3.3 mm, 3.4 mm, or 3.5 mm, or within any range bound by any two of those values (e.g., from 0.4 mm to 3.0 mm, from 0.3 mm to 2.7 mm, from 0.15 mm to 3.5 mm, from 0.2 mm to 3.5 mm, from 0.25 mm to 3.5 mm, from about 0.1 mm to 0.4 mm, from 0.1 mm to 0.4 mm, from 0.15 mm to 0.4 mm, from 0.2 mm to 0.4 mm, from 0.25 mm to 0.4 mm, from 0.095 mm to 0.3 mm, and so on). In embodiments, the thickness 22 is greater than 3.5 mm or less than 0.095 mm.

[0089] The edge 16 of the glass article 10 exhibits a surface roughness (Ro). Surface roughness (Ro) for purposes of this disclosure is defined by the ASME B46.1 standard. As described in ASME B46.1, Ro is the arithmetic average of the absolute values of the surface profile height deviations from the mean line, recorded within the evaluation length. In alternative terms, Ro is the average of a set of absolute height deviations of individual features of the surface relative to the mean. The surface roughness (Ro) can be determined using an atomic force microscope. In embodiments, the surface roughness (Ro) that the edge 16 exhibits is within a range of from 30 nm to 110 nm. In embodiments, the surface roughness (Ro) is 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, or 110 nm, or within any range bound by any two of those values (e.g., from 40 nm to 70 nm, from 50 nm to 100 nm, and so on). As will be further explained below, these values are lower than the surface roughness (Ro) values that an edge 16 of a glass article would exhibit if not treated with atmospheric-pressure plasma in accordance with the present disclosure.

[0090] The edge 16 of the glass article 10 has a density of particles 24. Particles 24 for purposes of this disclosure refer to any kind of particles, such as glass particles and dust particles. The density of the particles 24 upon the edge 16 is less than 2 particles per 0.1 square millimeter. As will be further discussed below, treating the edge 16 of the glass article 10 with the atmospheric-pressure plasma reduces the density of particles 24 upon the edge 16 more so than other ways of treating the edge 16.

[0091] The glass article 10 exhibits a residual stress at and near the edge 16. "At or near the edge 16" means from the edge 16 surface into the glass article 10 a distance of 1000 pm from the edge 16, unless context dictates otherwise. The residual stress at and near the edge 16 is a consequence of treating the edge 16 with the atmospheric-pressure plasma, which heats the edge 16. The edge 16, heated, subsequently cools. The change in temperature at and near the edge 16 causes the residual stress within the glass article 10 at and near the edge 16. The residual stress that the glass article 10 exhibits at or near the edge 16 has a maximum deviation from 0 that is within the range of from -100 MPa to 40 M Pa. A negative value for the residual stress means that the residual stress is a compressive stress. In contrast, a positive value for the residual stress means that the residual stress is a tensile stress. As will be discussed further below, whether the maximum deviation from 0 for the residual stress is a tensile stress or compressive stress may be a function of the gasses or ratio of gasses from which the plasma is made, the rate at which the edge moves relative to the plasma, among other factors. In embodiments, the residual stress that the glass article 10 exhibits at or near the edge 16 has a maximum deviation from 0 that is -100 MPa, -90 MPa, -80 MPa, -70 MPa, - 60 MPa, -50 MPa, -40 MPa, -30 MPa, -20 MPa, -10 MPa, 0 MPa, 10 MPa, 20 MPa, 30 MPa, or 40 MPa, or within any range bound by any two of those values (e.g., from -100 MPa to -20 MPa, from -90 MPa to -40 MPa, -70 MPa to -20 MPa, -50 MPa to 0 MPa, and so on). In some instances, the residual stress is predominately or entirely compressive.

[0092] In embodiments, the maximum deviation from 0 of the residual stress is disposed at a position within the glass article 10 that is within 1000 pm from edge 16. Further, in embodiments, the residual stress within the glass article 10 at positions 1800 pm from the edge 16 and beyond is within a range of from -5MPa to 5MPa. Treating the edge 16 with the atmospheric-pressure plasma causes the residual stress to concentrate near the edge 16 (e.g., within 1000 pm from the edge 16). Further away from the edge 16 (e.g., 1800 pm from the edge 16 and beyond) has little or no residual stress from the atmospheric-pressure plasma treatment.

[0093] In embodiments, the residual stress at the edge 16 and to a distance of at least 100 pm into the glass article from the edge 16 is compressive. Treatment of the edge 16 with the atmospheric-pressure plasma as discussed herein can create a spike of compressive stress that occurs at the edge 16 and into the glass article 10 a short distance from the edge 16 (e.g., 100 pm). The spike is where the maximum value of the compressive stress at or near the edge 16 exists. Plotting the residual stress as a function of distance from the edge 16 reveals a slope. At least a portion of that slope has an absolute value of 0.2 MPa/pm or greater when proceeding from neutral towards greater compressive stress. The slope with that absolute value of 0.2 MPa/pm or greater occurs within 100 pm into the glass article from the edge. This aspect is further discussed below in relation to Example 7 and FIG. 24. [0094] In embodiments, the glass article has not been subjected to an annealing procedure. An annealing procedure would reduce the residual stress at and near the edge and flatten the slope of residual stress as a function of distance from the edge that might have existed before the annealing procedure was conducted.

[0095] Referring now to FIG. 2, in embodiments, the glass article 10 includes one or more regions 26a, 26b of compressive stress. For example, the glass article 10 can include a first region 26a of compressive stress contiguous with the first primary surface 12, and a second region 26b of compressive stress contiguous with the second primary surface 14. A region 28 of tensile stress within the glass article 10 balances the first region 26a of compressive stress and the second region 26b of compressive stress. As further discussed below, the glass article 10 can be subjected to an ion-exchange procedure to impart the one or more regions 26a, 26b of compressive stress. Other methods such as thermal tempering can be utilized as well. The one or more regions 26a, 26b of compressive stress render the glass article 10 scratch and impact resistant.

[0096] The glass article 10 need not be subjected to an ion-exchange process or otherwise have the one or more regions 26a, 26b of compressive stress. The plasma treatment of the edge 16 can increase the strength of the edge 16 and lower the surface roughness (Ro) at the edge 16 to render the glass article 10 suitable for some applications.

[0097] Referring now to FIGS. 3A and 3B, the glass article 10 exhibits high strength (e.g., flexural stress) at the edge 16 in response to a four-point flexural test according to ASTM C158, regardless of whether the glass article 10 includes the one or more regions 26a, 26b of compressive stress or not - however, the realm of possible values for the strength at the edge 16 that the glass article 10 exhibits is a function of whether the glass article 10 includes the one or more regions 26a, 26b of compressive stress or not. ASTM C158 refers to the "Standard Test Methods for Strength of Glass by Flexure (Determination of Modulus of Rupture)" published by ASTM International (West Conshohocken, Pennsylvania, USA). "Modulus of rupture" and "flexural stress" and "edge strength" may all be used herein interchangeably.

[0098] To conduct the four-point flexural test, the glass article 10 is placed with the second primary surface 14 down onto two supporting bars 30a, 30b spaced apart by 36 mm. The two supporting bars 30a, 30b each have a diameter of 6 mm. The first primary surface 12 faces and contacts two loading bars 32a, 32b spaced apart by 18 mm. The two loading bars 32a, 32b each have a diameter of 6 mm, as well. The loading bars 32a, 32b are disposed laterally between, but elevationally above, the supporting bars 30a, 30b. Edges 16 that have been plasma treated are placed laterally across the two loading bars 32a, 32b. Increasing load is applied via the loading bars 32a, 32b onto the glass article 10 at a rate of 5 mm/min. The data is plotted using Weibull plots in which the percent probability of fracture is plotted as a function of flexural stress. A BIO Weibull distribution flexural stress value is the load under which the probability of the glass article 10 failing is 10%.

[0099] In the event that the glass article 10 lacks the one or more regions 26a, 26b of compressive stress (e.g., the glass article 10 has not been subjected to an ion-exchange procedure), upon being subjected to the four-point flexural test according to ASTM C158, the glass article 10 exhibits a B10 Weibull distribution flexural stress value that is greater than or equal to 300 MPa. For example, the B10 Weibull distribution flexural stress can be 300 MPa, 325 MPa, 350 M Pa, 375 MPa, 400 MPa, 425 MPa, 450 MPa, 475 MPa, or 500 MPa, or within any range bound by any two of those values (e.g., from 300 MPa to 500 MPa, from 350 MPa to 475 MPa, and so on).

[0100] In the event that the glass article 10 includes one or more regions 26a, 26b of compressive stress (e.g., the glass article 10 has been subjected to an ion-exchange procedure), upon being subjected to the four-point flexural test according to ASTM C158, the glass article 10 exhibits a B10 Weibull distribution flexural stress value within a range of from 700 MPa to 900 MPa. For example, the B10 Weibull distribution flexural stress can be 700 MPa, 725 MPa, 750 M Pa, 775 MPa, 800 MPa, 825 MPa, 850 M Pa, 875 MPa, or 900 MPa, or within any range bound by any two of those values (e.g., from 725 MPa to 800 MPa, from 750 MPa to 875 MPa, and so on). The high flexural stress of the glass article 10 makes the glass article 10 especially useful for consumer applications, such as to cover displays within the interior of a vehicle 40 (see FIG. 5A) and as a component of an electronic device 42 (See FIG. 5B).

[0101] Referring now to FIG. 4, in embodiments, the glass article 10 in not entirely planar. For example, the first primary surface 12 and the second primary surface 14 can each include a non-planar portion 34. At the generally non-planar portion 34, the first primary surface 12 and/or the second primary surface 14, as the case may be, are curved. The first primary surface 12 and the second primary surface 14 can each include a planar portion 36, as well. Such embodiments can be useful where the glass article 10 covers a display in a relatively complex environment such as within an interior 38 of the vehicle 40 (e.g., at a dashboard).

[0102] Referring nowto FIGS. 5A and 5B, in embodiments, the glass article 10 is a component of the interior 38 of the vehicle 40 (see FIG. 5A) or a component of the electronic device 42 (see FIG. 5B). In the context of the vehicle 40, the glass article 10 may take the more complex shape that includes the non-planar portion 34 and cover one or more displays 44. A housing 46 can support the glass article 10 and, together with the glass article 10, house the display 44. The one or more displays 44 are thus visible from the interior 38 through the glass article 10. In the context of the electronic device 42, the glass article 10 may be entirely planar with a planar portion 36 and cover a display 44. The display 44 is thus visible through the glass article 10.

[0103] The glass article 10 can be any glass or glass-ceramic. In embodiments, the glass article 10 includes a borosilicate glass, an alumino boro silicate alkali-free glass, an aluminoborosilicate glass, an alkaline earth aluminoborosilicate glass, high purity fused silica, or an alkali-containing glass. In embodiments, the glass article 10 includes a composition including (on an oxide basis, before ion-exchange) 50 mol% to 80 mol% SiOz, 1 mol% to 5 mol% B2O3, 5 mol% to 20 mol% AI2O3, 7 mol% to 20 mol% Na2O, 1 mol% to 5 mol% MgO, and less than 0.5 mol% of each of K2O, Fe2C>3, ZrC>2, and SnC>2. Such compositions are ionexchangeable, allowing the glass article 10 to be ion-exchanged and form the one or more regions 26a, 26b of compressive stress. The glass article 10 can include rare earth oxides, such as Y2O3 and/or La2O3. The glass article 10 can be a non-silicate glass, such as a borate glass (e.g., a Zn-Bi-Borate glass, a boroaluminate glass), a phosphate glass (e.g., an aluminophosphate glass), a germanate glass, a fluorophosphate glass, a sulfophosphate glass, a vanadate glass, among others. Other glasses are possible for the glass article 10. The glass article 10 can be formed through any glass forming process, such as a fusion process, a float bath process, a press-rolling process, among others.

[0104] As mentioned, the glass article 10 can be a glass-ceramic. The term "glass ceramic" refers to a material comprising a glass phase and a crystalline ceramic phase, wherein the ceramic phase accounts for or comprises at least 50 volume percent of the material. The terms "glass ceramic" and "crystalline" are equivalent terms and may be used interchangeably herein. A glass-ceramic is nominally produced by a thermal process in which the as-made glass is thermally treated to produce a controlled crystalline phase. Examples of suitable glass-ceramics include U2O— AI2O3— SiC system (i.e. LAS-System) glass-ceramics, MgO— AI2O3— SiCk system (i.e. MAS-System) glass-ceramics, glass-ceramics including crystalline phases of any one or more of mullite, spinel, a-quartz, p-quartz solid solution, petalite, lithium disilicate, -spodumene, nepheline, alumina, and combinations thereof.

[0105] In embodiments, the composition of the glass article 10, for particular elements, is relatively constant after a short distance from the edge 16. For example, in embodiments, the number of atoms per volume of one or more of Mg, Ca, Al, and Sr is substantially constant at all positions within the glass article 10 from 30 nm from edge 16 to 200 nm from the edge 16. The atmospheric-pressure plasma treatment of the edge 16 causes little or no change to the density of atoms of one or more of Mg, Ca, Al, and Sr at positions from 30 nm from the edge 16 to 200 nm from the edge 16.

[0106] Referring now to FIG. 6, in embodiments, the glass article 10 includes a first chamfer portion 48. The first chamfer portion 48 transitions the edge 16 to the first primary surface 12. In embodiments, the glass article 10 includes a second chamfer portion 50. The second chamfer portion 50 transitions the edge 16 to the second primary surface 14. As further discussed below, the atmospheric-pressure plasma, either alone or together with a prior mechanical grinding, forms the first chamfer portion 48 and the second chamfer portion 50, if present.

[0107] Referring now to FIG. 7, in embodiments, the edge 16 of the glass article 10 provides an entirely curved transition from the first primary surface 12 to the second primary surface 14. In such embodiments, no portion of the edge 16 is planar. As further discussed, the curvature of the edge 16 can be a function of the placement of atmospheric-pressure plasma relative to the first primary surface 12, as well as the number of emitters (e.g., heads) of atmospheric-pressure plasma utilized.

[0108] Referring now to FIG. 8, a method 100 of treating a glass article to form the glass article 10 is herein discussed.

[0109] Referring additionally to FIG. 9, at a step 102, the method 100 includes contacting the edge 16 of the glass article 10 with atmospheric-pressure plasma 104. While the atmospheric- pressure plasma 104 contacts the edge 16, at least one of the glass article 10 and the atmospheric-pressure plasma 104 is moved 106 relative to the other. In other words, the glass article 10 can be caused to move 106 relative to the atmospheric-pressure plasma 104, the atmospheric-pressure plasma 104 can be moved 106 to the glass article 10, or both. [0110] The atmospheric-pressure plasma 104 is generated from gas. For purposes of this disclosure, the term "plasma" refers to an ionized gas comprising high temperature positive ions and free electrons. For purposes of this disclosure, the term "atmospheric pressure plasma" refers to a flow of plasma discharged from an aperture, wherein the plasma pressure approximately matches that of the surrounding atmosphere, including conditions wherein the plasma pressure is between 90% and 110% of 101.325 kilopascals (standard atmospheric pressure). The plasma exits a head 108 through the aperture 111 as a jet of plasma 104. Plasma 104 can be directed toward the edge 16 under a variety of processing parameters. In embodiments, plasma 104 can be generated at a power of at least about 300 watts, such as a power of at least about 500 watts, including a power of from about 300 watts to about 800 watts and further including a power of from about 500 watts to about 800 watts. In embodiments, the plasma 104 is generated via a direct current high voltage discharge that generates a pulsed electric arc, such as a voltage discharge of at least about 5 kV, such as from about 5 kV to about 15 kV. In embodiments, the plasma 104 is generated at a frequency of at least about 10 kHz, such as from about 10 kHz to about 100 kHz. In embodiments, the plasma 104 can have a beam length 110 of from about 5 millimeters to about 40 millimeters and a widest beam width 112 of from about 0.5 millimeters to about 15 millimeters.

[0111] In embodiments, the gas from which the atmospheric-pressure plasma 104 is generated is one or more of nitrogen gas, compressed dry air ("CDA") gas, argon gas, hydrogen gas, and helium gas. In embodiments, the gas is a combination of nitrogen gas and helium gas. In embodiments, the gas is a combination of nitrogen gas and hydrogen gas.

[0112] In embodiments, a gap distance 114 between the head 108 and the edge 16 is at least about 1 millimeter, such as at least about 2 millimeters, and further such as at least about 4 millimeters, and yet further such as at least about 5 millimeters, such as from about 1 millimeter to about 10 millimeters, including from about 5 millimeters to about 10 millimeters. The gap distance 114 may be greater than 10 millimeters. In embodiments, the number of times that the head 108 moves over any particular portion of the edge 16 (referred to herein as "scan pass") can be at least 1 pass, such as at least 2 passes, and further such as at least 3 passes, and yet further such as at least 4 passes, including from 1 pass to 10 passes, and further including from 2 passes to 6 passes. In embodiments, the number of scan passes is 1 pass. [0113] The at least one of the glass article 10 and the atmospheric-pressure plasma 104 move 106 relative to each other at relatively high speeds and still impart the benefits described herein. In embodiments, the at least one of the glass article 10 and the atmospheric-pressure plasma 104 move 106 relative to each other at a speed that is greater than or equal to 20 mm/second. In embodiments, the speed at which the at least one of the glass article 10 and the atmospheric-pressure plasma 104 move 106 relative to each other is within a range of from 20 mm/second to 200 mm/second. In embodiments, the speed at which the at least one of the glass article 10 and the atmospheric-pressure plasma 104 move 106 relative to each other is 20 mm/second, 30 mm/second, 40 mm/second, 50 mm/second, 60 mm/second, 70 mm/second, 80 mm/second, 90 mm/second, 100 mm/second, 110 mm/second, 120 mm/second, 130 mm/second, 140 mm/second, 150 mm/second, 160 mm/second, 170 mm/second, 180 mm/second, 190 mm/second or 200 mm/second, or within any range within any two of those values (e.g., from 30 mm/second to 80 mm/second, from 40 mm/second to 90 mm/second, from 20 mm/second to 100 mm/second, and so on).

[0114] The step 102 of contacting the edge 16 of the glass article 10 with the atmospheric- pressure plasma 104 can shape the glass article 10 at the edge 16. Referring additionally to FIG. 10, in embodiments, the atmospheric-pressure plasma 104 contacts the edge 16 at an angle (a) other than perpendicular to the edge 16. In other words, the jet of plasma 104 exiting the head 108 can be directed toward the glass article 10 at an angle (a) that is between orthogonal to the edge 16 and orthogonal to the first primary surface 12, such as tilted to partially contact both the first primary surface 12 and the edge 16. In such situations, the atmospheric-pressure plasma 104 can generate the first chamfer portion 48 of the edge 16, and the first chamfer portion 48 has the low surface roughness (Ro) herein described for the edge 16 (e.g., from 30 nm to 110 nm). Similarly, positioning the head 108 to direct the atmospheric-pressure plasma 104 at an angle (a) that is between orthogonal to the edge 16 and orthogonal to the first primary surface 12 can generate the curved surface at the edge 16 (as illustrated at FIG. 6). When the atmospheric-pressure plasma 104 is utilized to shape the glass substrate at the edge 16, such as to add the first chamfer portion 48 or the curved surface, a subsequent mechanical polishing step is not needed and would only increase the surface roughness (Ro) and introduce flaws. Shaping the glass article 10 near the edge 16, without the use of the atmospheric-pressure plasma 104 as herein described, would require the use of grinding wheels and multiple fine polish cycles, which takes more time and generates a greater surface roughness. Further, grinding and polishing wheels wear and thus generate a wavy surface at the edge 16, leading to dimensional instability. Moreover, grinding and polishing wheels generate debris and thus leave a much greater density of particles 24 upon the glass article 10 than if atmospheric-pressure plasma 104 was utilized to shape the glass article 10 near the edge 16. However, as discussed further below, the glass article 10 can be shaped first mechanically and then subsequently treated with the atmospheric-pressure plasma 104 to reduce the density of particles 24 and the surface roughness (Ro) to the ranges stated herein.

[0115] In embodiments, referring additionally to FIG. 11, contacting the edge 16 of the glass article 10 with the atmospheric-pressure plasma 104 includes simultaneously contacting the edge 16 with more than one atmospheric-pressure plasmas 104 such that heat generated by any two adjacent plasma 104 jets at least partially overlaps. For example, heat from a first atmospheric-pressure plasma 104a from a first head 108a can partially overlap heat from a second atmospheric-pressure plasma 104b from a second head 108b. The first head 108a can be positioned to direct the heat from the first atmospheric-pressure plasma 104a partially onto the first primary surface 12 and partially onto the edge 16, while the second head 108b can be positioned to direct the heat from the second atmospheric-pressure pressure plasma 104b partially onto the second primary surface 14 and partially onto the edge 16. In such arrangements, the step 102 of contact! ng the edge 16 with the atmospheric-pressure plasma 104 can generate the first chamfer portion 48 and the second chamfer portion 50, or the edge 16 with the curved surface. Further, the use of the second head 108b can direct glass reflow generated from first head 108a to more precisely control the shape of the glass article 10 at the edge 16.

[0116] Referring additionally to FIG. 12A, at a step 128, the method 100 further includes imparting additional heat 130 to one or both of the first primary surface 12 and the second primary surface 14 proximate the edge 16 of the glass article 10. The additional heat 130 may be imparted at a distance on the order of about 1 cm to about 3 cm from where the plasma contacts the edge 16. The step of imparting additional heat 130 occurs simultaneously with the step 102 of contacting the edge 16 of the glass article 10 with the atmospheric-pressure plasma 104. In embodiments, as illustrated, a first laser source 132a directing a first laser beam 134a to the first primary surface 12 is utilized to impart the additional heat 130. A second laser source 132b can direct a second laser beam 134b to the second primary surface 14, as well to impart the additional heat 130. In other embodiments (not illustrated), one or more heat lamps, or additional atmospheric-pressure plasma 104 emitters can be utilized to impart the additional heat 130.

[0117] Contacting the edge 16 with the atmospheric-pressure plasma 104 at the step 102 generates the residual stress at and near the edge 16, as mentioned above. After the steps 102 and 128 of contacting the edge 16 with the atmospheric pressure plasma 104 and adding the additional heat 130, the residual stress that the glass article 10 exhibits is within a range of from -100 MPa to 40 MPa, where negative values are compressive stress and positive values are tensile stress. Residual stress at or near the edge 16 of less than -100 MPa (e.g., greater compressive stress, such as -110 MPa, -120 MPa and so on) would increase the propensity of the glass article to warp. Residual stress at or near the edge 16 of greater than 40 MPa (e.g., greater tensile stress, such as 50 MPa) would increase the propensity of the glass article to fracture relatively easily (e.g., spontaneously).

[0118] Incorporation of a gas or gasses with a relatively high thermal conductivity (e.g., hydrogen gas and helium gas) may allow for the generation of residual compressive stress (negative values). For example, plasma 104 formed from a combination of nitrogen and argon gasses alone might generate tensile residual stress near the edge 16 of the glass article 10, while plasma 104 formed from a combination of nitrogen, argon, and hydrogen gasses might generate compressive residual stress near the edge 16 of the glass article 10.

[0119] Imparting the additional heat 130 allows for the edge 16 to move 106 relative to the plasma 104 at a faster rate than might be feasible without the additional heat (e.g., 20 mm/second to 100 mm/second). The rate at which the edge 16 can move 106 relative to the plasma, as well as the residual stress, may be limited by the intrinsic thermal conductivity of the gas or gasses used to form the atmospheric-pressure plasma 104. Without the additional heat 130, even plasma 104 generated from relatively highly conductive gasses like helium or hydrogen might generate tensile rather than compressive residual stress at or near the edge 16 when the edge 16 moves at a sufficiently high rate relative to the plasma 104. This is due to the temperature gradient that the plasma 104 generates near the edge 16.

[0120] Imparting additional heat 130 to the glass article 10 near the edge 16, either at a position before the atmospheric-pressure plasma 104 contacts the glass article 10 or at a position after the atmospheric-pressure plasma 104 contacts the glass article 10 flattens the thermal gradient compared to if no additional heat 130 was imparted. FIG. 12B illustrates predicted thermal gradients for different scenarios while treating the edge 16 with atmospheric-pressure plasma 104. At section (a), no additional heat 130 is imparted, and the plasma 104 generates a relatively steep thermal gradient at or near the edge 16 of the glass article 10 - one that would generate residual tensile stress at or near the edge 16 at faster rates of plasma 104 treatment. At section (b), additional heat 130 is added to the glass article 10 near the edge 16 before the plasma contacts the glass article 10. At section (c), additional heat 130 is added to the glass article 10 near the edge 16 after the plasma 104 contacts the glass article 10. The arrows indicate the direction of movement 106 of the glass article 10. The additional heat 130 flattens the thermal gradient. Thus, the additional heat 130 should reduce or prevent residual tensile stress generated at or near the edge 16, which allows for faster plasma 104 treatment rates. Stated another way, the step 102 of the plasma 104 treatment of the edge 16 induces residual tensile stress at or near the edge 16, more so as the speed of the plasma 104 treatment increases. However, the step 128 of imparting the additional heat 130 to the glass article 10 simultaneously with the plasma 104 treatment step 102 causes the glass article 10 near the edge 16 to cool after the edge 16 cools, thus pulling the residual stress at the edge 16 from tensile to neutral or compressive residual stress.

[0121] Further, directing the atmospheric-pressure plasma 104 not directly to the edge 16 of the glass article 10 but, rather, at a trailing or leading angle can change the thermal gradient at or near the edge 16.

[0122] In embodiments, the glass article 10 is not subjected to an annealing procedure, after the step 102 of contacting the edge 16 with the atmospheric pressure plasma 104 and the step 128 of imparting additional heat 130 to one or both of the first primary surface 12 and the second primary surface 14 proximate the edge 16. In short, the method 100 in embodiments includes no annealing of the glass article 10 after plasma 104 treatment of the edge 16. As mentioned, too much residual compressive stress from the plasma 104 treatment step 102 could cause the glass article 10 to warp. The glass article 10 could be subjected to an annealing procedure to reduce the residual compressive stress but such an annealing procedure is not needed for the method 100. Instead, the rate at which the edge 16 moves relative to the plasma 104 can be increased in orderto reduce the residual compressive stress (e.g., bring the compressive stress back into a range of -100 MPa to 0 ). Further, the selection of gasses, or flow rate ratios, can be changed to reduce the residual compressive stress. Such an annealing procedure can be very expensive, and there is a large cost savings by not having to subject the glass article 10 to an annealing procedure.

[0123] Referring additionally to FIGS. 13A-13B, in embodiments, the method 100 further includes the step 116 of grinding or laser-cutting the edge 16. The step 116 of grinding or laser-cutting the edge 16 occurs before the step 102 of treating the edge 16 with plasma 104. Grinding of the edge 16 can include the use of one or more grinding wheels 118 that rotate and grind away a portion of the glass article 10 to form the edge 16 that is subsequently treated with the plasma 104 at the step 102. The grinding wheels 118 may additionally add the chamfer portion 48 (FIG. 6) to the glass article 10. Laser-cutting the edge 16 can include a laser source 120 that emits a laser beam 122. The laser beam 122 is directed to a workpiece 124, perforates the same, and allows the separation of the glass article 10 from the workpiece 124 with the edge 16 now formed.

[0124] The step 116 of grinding or laser cutting the edge 16 generally renders the surface roughness (Ro) of the edge 16 well above 110 nm, such as about 800 nm in some instances or even higher. The step 102 of treating the edge 16 of the glass article 10 with the atmospheric-pressure plasma 104 reduces the surface roughness (Ro) of the edge 16 to be within the stated range of 30 nm to 110 nm.

[0125] In addition, the step 116 of grinding or laser cutting the edge 16 causes a relatively high density of particles 24 to be disposed upon the glass article 10 at the edge 16 or chamfer portion. The step 102 of treating the edge 16 of the glass article 10 with the atmospheric- pressure plasma 104 reduces the density of the particles 24 to be less than the stated value of 2 particles per 0.1 square millimeter.

[0126] Further, the step 116 of grinding or laser cutting the edge 16 introduces inwardly extending flaws at the edge 16. Those flaws negatively affect the edge strength of the glass article 10 and thus render the glass article 10 more susceptible to fracture. The step 102 of contacting the edge 16 with the atmospheric-pressure plasma 104 reduces the number of, and depth of, those flaws. Thus, the step 102 of contacting the edge 16 with the atmospheric- pressure plasma 104 increases the edge strength of the article to the value described above. The glass article 10, after the step 102, exhibits a B10 Weibull distribution edge strength value that is greater than or equal to 300 MPa.

[0127] In embodiments, at a step 126, the method 100 further includes subjecting the glass article 10 to an ion-exchange procedure. The step 126 of ion-exchanging the glass article 10 occurs after the step 102 of treating the edge 16 of the glass article 10 with the atmospheric- pressure plasma 104. The ion-exchange procedure generates the one or more regions 26a, 26b of compressive stress within the glass article 10.

[0128] In an ion-exchange procedure, ions at and near the first primary surface 12 and optionally the second primary surface 14 of the glass article 10 are replaced by— or exchanged with— larger ions having the same valence or oxidation state as the ions present in the glass. The larger ions are typically monovalent metal cations such as, but not limited to, Li⁺, Na⁺, K⁺, Rb⁺, Cs⁺, Ag⁺, Tl⁺, Cu⁺, and the like. To be optimally suitable for the step 126 of undergoing the ion-exchange procedure, the composition of the glass article 10 (e.g. borosilicate glass composition) includes ion-exchangeable ions (e.g., Li⁺ or Na⁺). The mismatch in ion size generates the one or more regions 26a, 26b of compressive stress, which inhibits both crack formation and propagation. For the glass article 10 to fracture, the applied stress must place the mechanical defect under sufficient tension to propagate existing flaws. If these flaws exist within the ion-exchanged depth of layer, the applied stress must first overcome the compressive stress at the first primary surface 12 of the glass article 10.

[0129] The ion-exchange procedure includes immersing the glass article 10 in a molten salt bath containing the larger ions to be exchanged with the smaller ions in the glass article 10. Other ways besides use of a bath are possible that bring the glass article 10 in contact with the molten salt to cause an exchange of ions. In some embodiments, the ion-exchange bath comprises, consists essentially of, or consists of at least one alkali metal salt such as, but not limited to, nitrates, sulfates, and halides of sodium and potassium or other alkali metal elements. In embodiments, the ion-exchange bath includes salts of other monovalent metals (e.g., Ag, Cu, or the like). In embodiments, the ion-exchange bath is an eutectic mixture of such salts or a molten solution of one salt in a second salt. One non-limiting example of a molten salt solution is a solution of potassium nitrate in ammonium nitrate.

[0130] Parameters for the ion-exchange procedure including, but are not limited to, bath composition and temperature, immersion time or interaction time, the number of immersions of the glass in a salt bath (or baths), use of multiple salt baths, additional steps such as annealing, washing, and the like, are generally determined by the composition of the glass article 10, the compressive stress at the first primary surface 12 (and optionally the second primary surface 14) of the glass article 10 and the depth of the compressive layer of the glass article 10 desired to be achieved by the ion-exchange procedure. By way of example, ion-exchange of alkali metal-containing glass articles 10 may be achieved by immersion of the glass article 10 in at least one molten alkali metal salt bath. The temperature of such KNCh molten salt baths, for example, is typically in a range from about 380 °C up to about 450 °C, and immersion times can range from minutes up to about 16 hours. However, temperatures and immersion times that are different from those described herein may also be used. Such ion-exchange treatments typically result in a strengthened glass article 10 with the first primary surface 12 (and optionally the second primary surface 14) that is under compressive stress.

[0131] As mentioned, the step 116 of grinding or laser-cutting the edge 16 can introduce inwardly extending flaws at the edge 16. Ion-exchanging the glass article 10 would only enlarge these flaws and potentially create new ones, further reducing the edge strength of the glass article 10 and countering any strength benefits gained via the generation of the regions 26a, 26b of compressive stress at the first primary surface 12 and the second primary surface 14. However, the step 102 of contacting the edge 16 of the glass article 10 with the atmospheric-pressure plasma 104 reduces the depth of the flaws, makes the flaws more round, or eliminates those flaws. The step 126 of subsequently ion-exchanging the glass article 10 thus more optimally enhances the edge strength of the glass article 10 to the values mentioned above - a B10 Weibull distribution edge strength value within a range of from 700 MPa to 900 MPa.

[0132] The step 102 of contacting the edge 16 with the atmospheric-pressure plasma 104 is advantageous over other ways of reducing the inwardly extending flaws at the edge 16 before subjecting the glass article 10 to the ion-exchange procedure. The edge 16 could be fine polished instead of treated with plasma 104. However, fine polishing takes more time, is more expensive, and yields less strong edge strength than plasma 104 treatment of the edge 16 according to the method 100.

[0133] Unlike other methods of finishing the edge 16 of the glass article 10, the present method 100 is scalable. In other words, the method 100 is able to treat the edge 16 of the glass article 10 of any dimensions, including relatively large sizes and unusual shapes. In contrast, finishing the edge 16 via other methods such as fine polishing may not be suitable for a glass article 10 of relatively large size and it may be more difficult for a grinding wheel to contact the edge 16 when the glass article 10 has unusual dimensions. [0134] Referring now to FIG. 14, a system 200 to treat the edge 16 of the glass article 10 includes a support 202 and the first head 108a. The support 202 is configured to support the glass article 10 with the edge 16. For example, the support 202 can be disposed underneath the glass article 10, and may include one or more suction apparatuses to selectively couple to the glass article 10 and secure the article while the edge 16 is being treated with plasma 104a. The first head 108a is configured and positioned to emit atmospheric-pressure plasma 104a onto the edge 16 of the glass article 10. As discussed the first head 108a can be positioned to emit the plasma 104a orthogonally onto the edge 16 as in FIG. 9. Alternatively, the first head 108a can be positioned to emit plasma 104a at an angle a other than orthogonal to the edge 16, as in FIG. 10. One or both of the support 202 and the first head 108a are movable 106 relative to the other. The movement 106 allows the first head 108a to emit plasma 104a onto all desired portions of the edge 16. The movement 106 can be at a rate with a range, as mentioned above, of from 20 mm/second to 100 mm/second. The system 200 can be utilized to effectuate the step 102 of the method 100.

[0135] In embodiments, the system 200 includes the second head 108b. The second head 108b is configured and positioned to emit atmospheric-pressure plasma 104b onto the edge 16 of the glass article 10. The first head 108a and the second head 108b are positioned relatively to each other and the support 202 so that the heat of the plasma 104a from the first head 108a and the heat of the plasma 104b from the second head 108b at least partially overlap, such as illustrated at FIG. 11.

[0136] In embodiments, the system 200 includes one or more heat emitters 132 (e.g., the first laser source 132a, the second laser source 132b). The one or more heat emitters are positioned relative to the support 202 to emit heat onto one or both of the first primary surface 12 and second primary surface 14 of the glass article 10 near where first head 108a emits plasma 104a onto the edge 16 of the glass article 10. As discussed above, the one or more heat emitters 132 can include a laser source (e.g., the first laser source 132a, the second laser source 132b), a lamp, or a head (e.g., another head 108) configured to emit atmospheric- pressure plasma 104.

[0137] In embodiments, the first head 108a is positioned relative to the support 202 to emit plasma 104a generally parallel to the first primary surface 12 orthogonal to the edge 16 of the glass article 10. Such an instance is illustrated at FIGS. 9 and 12A. In other embodiments, the first head 108a is positioned relative to the support 202 to emit plasma 104a at an angle a between (i) orthogonal to the first primary surface 12 of the glass article 10 and (ii) orthogonal to the edge 16 of the glass article 10. Such an instance is illustrated at FIG. 10.

[0138] In embodiments, referring now to FIG. 15, the first head 108a includes a slot 204 and a plurality of apertures 206 at the slot 204. The slot 204 is configured to accept the edge 16 of the glass article 10. The edge 16 is slotted within the slot 204. The first head 108a thus partially extends over the first primary surface 12, extends around the edge 16, and partially extends beneath the second primary surface 14. The plurality of apertures 206 are positioned to emit plasma 104a onto at least two of the first primary surface 12, the edge 16, and the second primary surface 14 of the glass article 10. In embodiments, the plurality of apertures 206 are positioned to emit plasma 104a onto all three of the first primary surface 12, the edge 16, and the second primary surface 14. As illustrated, the slot 204 can be arc-shaped.

[0139] Examples

[0140] Example 1 - For Example 1, the edge of sample glass articles including two different glass compositions were finished according to different methods. A first set ("Set 1A") of sample glass articles was prepared from an alkali aluminosilicate glass composition. A portion of the samples was not subjected to an ion-exchange procedure. The edge of one sample ("Sample 1A1") from the set was rough ground with #400 grit. The edge of another sample ("Sample 1A2") was rough ground with #400 grit and then fine polished with #1000 grit. The edge of a final sample ("Sample 1A3") was rough ground with #400 grit and then treated with atmospheric-pressure plasma according to the present disclosure. Scanning electron microscope images of all three samples was then captured. The images are reproduced at FIG. 16. The images reveal that finishing the edges with rough grinding and fine polishing leaves visible marks at the edge. However, the image for Sample 1A3 reveals that finishing the edge with atmospheric-pressure plasma leaves no visible marks at the edge and a visually smooth surface.

[0141] A second set ("Set IB") of sample glass articles was prepared from another alkali aluminosilicate glass composition. A portion of the samples was not subjected to an ionexchange procedure. The edge of one sample ("Sample 1B1") was not finished in any manner and represents an edge as cut via laser from a larger workpiece. The edge of another sample ("Sample 1B2") was finished with only an atmospheric-pressure plasma generated from nitrogen gas and helium gas at a 97:3 flow rate ratio. The edge of a final sample ("Sample 1B3") was finished with only an atmospheric-pressure plasma generated from pure nitrogen gas. Optical microscope images of all three samples were then captured, and the surface roughness (Ro) at the edge of all three samples was determined. The images are reproduced at FIG. 16. The image of Sample 1B1 that was laser cut reveals a visually rough surface, and the surface roughness (Ro) was 240 nm. The image of Sample 1B2 that was treated with the atmospheric-pressure plasma reveals a visually smooth surface, and the surface roughness (Ro) was 50 nm. The image of Sample 1B3 that was treated with the atmospheric-pressure plasma reveals a visually smooth surface, and the surface roughness (Ro) was 40 nm.

[0142] A portion of Samples 1A2 and Samples 1A3 was then subjected to an ion-exchange procedure to generate regions of compressive stress contiguous with the first primary surface and the second primary surface of the samples. The ion-exchanged samples were then subjected to the four-point flexural test according to ASTM C158 as described herein to determine the flexural stress of each sample. A Weibull plot was then prepared. The Weibull plot is reproduced at FIG. 17. The Weibull plot reveals that the BIO value for the Samples 1A2 (ground and polished but not plasma treated) was 611 MPa, while the BIO value for the Samples 1A3 (ground and plasma treated) was 772 MPa. The BIO value for the Samples 1A3 (ground and plasma treated) was thus 26% stronger than the BIO value for the Samples 1A2 (ground and polished but not plasma treated). Treating the edge of glass articles with atmospheric-pressure plasma according to the present disclosure increases the edge strength of the glass articles.

[0143] A portion of Samples 1B1, Samples 1B2, and Samples 1B3 was then subjected to an ion-exchange procedure to generate regions of compressive stress contiguous with the first primary surface and the second primary surface of the samples. The ion-exchanged samples were then subjected to the four-point flexural test according to ASTM C158 as described herein to determine the edge strength of each sample. A Weibull plot was then prepared. The Weibull plot is reproduced at FIG. 18. The Weibull plot reveals that the BIO value for the Samples 1B1 (laser cut and no edge treatment) was 563 MPa, while the B10 value for the Samples 1B2 (plasma treated) was 766 MPa, and the B10 value for the Samples 1B3 (plasma treated) was 792 MPa. The B10 value for the Samples 1B2 (plasma treated) was thus 36% stronger than the B10 value for the Samples 1B1 (laser cut with no edge treatment). The B10 value for the Samples 1B3 (plasma treated) was thus 41% stronger than the B10 value for the Samples 1B1 (laser cut with no edge treatment). Treating the edge of glass articles with atmospheric-pressure plasma according to the present disclosure increases the edge strength of the glass articles. The atmospheric-pressure plasma reduces the size and rounds the flaws existing at the edge before the ion-exchange procedure is performed. All samples for Example 1 had a thickness of 1.1 mm.

[0144] Example 2 - For Example 2, samples of a glass article having an alkali aluminosilicate glass composition were prepared, each having a thickness of 1.1 mm. For Sample 2A, the edge was rough ground with a #400 grit wheel. For Sample 2B, the edge was rough ground and then fine polished with a #1000 grit wheel. For Sample 2C, the edge was rough ground, then fine polished, and then treated with atmospheric-pressure plasma according to the present disclosure. An optical microscope was used to capture an image of the edge of each sample, and the surface roughness (Ro) at the edge was determined. The images for each sample are reproduced at FIG. 19, as is the determined surface roughness (Ro). As the images reveal, Sample 2A (rough ground) and Sample 2B (rough ground and fine polished) had a visibly rough surface at the edge, with surface roughnesses (Ro) of 610 nm and 410 nm to 450 nm, respectively. However, Sample 2C (rough ground, fine polished, and plasma treated) had a visibly smooth surface at the edge, with a surface roughness of less than 100 nm. To achieve such a surface roughness (Ro) of under 100 nm, multiple additional fine polishing steps with #3000 grit and #5000 grit wheels would be required. Further, with plain sight and without the use of a microscope, the edge of Sample 2C was transparent, while the edges of Samples 2A and 2B were hazy and not transparent.

[0145] Example 3 - For Example 3, Samples 3A-3C were prepared. With rough grinding followed by fine polishing, the edge of Sample 3A was finished and a first chamfer portion and a second chamfer portion were created. Atmospheric-pressure plasma of the present disclosure finished the edges of Samples 3B and 3C and created a first chamfer portion and a second chamfer portion. Optical microscope images of the manipulated surfaces for each sample were captured. In addition, cross-sections of each sample were prepared and images of the cross-sections were captured. The images are reproduced at FIG. 20. The images reveal that Samples 3B and 3C had a visibly smoother surface than Sample 3A. In addition, the image of the cross-section for Samples 3A and 3C reveals that atmospheric-pressure plasma can generate chamfer portions with nearly the same geometry as chamfers generated by rough grinding followed by fine polishing. The image of the cross-section for Samples 3B and 3C reveals that that atmospheric-pressure plasma can generate chamfer portions with different geometries depending on plasma conditions and plasma positioning relative to the sample. For example, higher energy and stronger flow plasma can generate chamfer portions with a more rounded geometry (e.g., Sample 3B). Samples 3A-3C each had a thickness of 1.3 mm. [0146] Example 4 - For Example 4, two samples of a glass article were prepared, Sample 4A and Sample 4B. The edges of both samples were then treated with atmospheric-pressure plasma according to the present disclosure. Sample 4A was treated with atmospheric- pressure plasma formed from nitrogen gas and argon gas at a gas flow ratio of 83:17. Sample 4B was treated with atmospheric-pressure plasma formed from nitrogen gas, argon gas, and hydrogen gas at a gas flow ratio of 77:16:7. The thermal profile near the edge of each sample was measured during the cooling process from 0 second to 0.5 second after contact with the plasma and a Polscope (polarized light microscopy) image was captured from which the residual stress distribution at or near the edge could be determined. The thermal profiles, images, and residual stress distributions are reproduced at FIGS. 21A and 21B. Comparing the thermal profiles reveals that Sample 4B cooled slightly faster near the surface of the edge than Sample 4A, but cooled more slowly away from the edge than sample 4A. Consequently, Sample 4B, which was contacted with plasma partially formed from hydrogen gas, has a more uniform temperature profile after 0.5 seconds than Sample 4A. The not-uniform temperature profile of Sample 4A would be expected to generate a large tensile stress according to the equation Stress = E * CTE * AT, where E is the elastic modulus of the glass article, CTE is the coefficient of thermal expansion of the glass article, and AT is the temperature difference between the surface of the edge and the 1-2 mm into the sample from the edge. The Poloscope image for Sample 4A confirms the deduction, with the plasma treatment causing a maximum deviation from 0 of +48 MPa (tensile) for the residual stress. In contrast, the Poloscope image for Sample 4B reveals a maximum deviation of from 0 of -63 MPa (compressive).

[0147] Example 5 - For Example 5, the maximum deviation from 0 for the residual compressive stress at or near the edge generated during plasma treatment was determined as a function of (i) gasses utilized to form the plasma, (ii) flow rate ratios for the gasses utilized, and (iii) the speed at which the edge moves relative to the plasma. For one set of samples (Samples 5A), the plasma was generated from a combination of hydrogen gas and nitrogen gas. For another set of samples (Samples 5B), the plasma was generated from a combination of helium gas and nitrogen gas. The flow rate ratios utilized 1%, 2%, 3%, 6%, and 7% hydrogen gas or helium gas, as the case may be, with balance nitrogen gas. A third set of samples (Samples 5C) utilized 100 percent nitrogen gas. The speeds ranged from 2 mm/second to 7 mm/second. No additional heating was imparted to the glass articles near the edge. The results are graphically reproduced at FIG. 22. All samples had a thickness of 0.5 mm, and were of the same alkaline earth boro-aluminosilicate glass. The results reveal that as the speed of the plasma treatment increases, the higher the propensity of the glass article to crack from residual tensile stress, regardless of whether the plasma was partially formed from a relatively highly conductive gas like helium gas or hydrogen gas. The faster the rate of the plasma treatment, the larger the thermal gradient from the edge into the sample and thus a higher degree of residual tensile stress.

[0148] Example 6 - For Example 6, a computational model was utilized to determine the thermal gradient that plasma treatment at an edge of a glass article would generate within the glass article as a function of angle of plasma treatment relative to the edge. Two scenarios were considered. For each scenario, a glass article was modeled with the edge facing upwards and the head directing plasma downwards to the edge. The head was positioned to direct the plasma level perpendicularly to the edge in the sense that the head was not pivoted toward a first primary surface or a second primary surface of the glass article. For Scenario 6A, the head is positioned to direct the plasma at a right angle relative to the edge - directly at the edge both in terms of depth and horizontally. For Scenario 6B, the head is positioned to direct the plasma to the edge at an angle deviated from horizontal. The computed thermal distributions are graphically reproduced at FIG. 23. Compared to Scenario 6A, Scenario 6B generates a more uniform thermal gradient from the edge inward into the glass article.

[0149] Example 7 - For Example 7, samples of a glass article of a common composition were prepared. The edge of one sample (Sample 7A) was subjected to a flame finishing treatment, with the flame directly perpendicularto the edge (not tilted to either the first primary surface or second primary surface). The edges of another set of samples (Samples 7B-7D) were treated with atmospheric-pressure plasma according to the present disclosure, with the plasma again directly perpendicular to the edge (not tilted to either the first primary surface or second primary surface). The gas or gasses used to form the plasmas of Samples 7B-7D varied - with Sample 7B utilizing helium and nitrogen gasses, Sample 7C utilizing only nitrogen gas, and Sample 7D utilizing helium and nitrogen gasses. The edges of a final sample (Sample 7E) were treated with atmospheric-pressure plasma according to the present disclosure, with the plasma tilted so as to contact both the first primary surface and the edge of the sample. The plasma of Sample 7E was formed from helium and nitrogen gasses. The residual stress was then determined as a function of distance from the edge, for each sample. The plasma orientation relative to the sample, as well as the results of the residual stress determinations are reproduced at FIG. 24.

[0150] For Sample 7A, treated with flame rather than plasma, the residual stress at the edge and to a distance of at least 2000 pm from the edge is entirely tensile, as the graph of FIG. 24 reveals. There is no spike in residual compressive stress - just relatively constant tensile stress from the edge surface to 1500 pm or so into the glass article. Such residual tensile stress typically requires annealing or quenching after the flame treatment in order to eliminate the tensile stress.

[0151] For Samples 7B-7E, treated with plasma, the graph of the residual stress determinations reveals that a spike in compressive stress occurs at the edge surface. Note that the surface of the edge occurs at about 500 pm on the x-axis of FIG. 25. More specifically, for Samples B-E, all treated with plasma, the residual stress at the edge and to a distance of at least 100 pm is compressive (e.g., has negative values on the graph of FIG. 24). In addition, for all of Samples 7B-E, the residual stress as a function of distance from the edge into the glass article as graphed at FIG. 24 has a slope. For example, for Sample 7D, the residual stress starts at 0 at the edge of the glass article (represented by about 500 pm on the x-axis of the graph) and then spikes to about -65 MPa (compressive stress) within about 100 pm into the glass article from the edge. That spike into compressive stress has a slope. The slope can be quantified as about -65 MPa/100 pm, or about -0.65 MPa/pm. The absolute value then of that slope is 0.65 MPa/pm, and the slope is towards greater compressive stress. The remainder of the plasma treated samples (Samples 7B, 7C, and 7E) likewise all have a similar spike in residual compressive stress that occurs from the edge and into at least 100 pm into the glass article from the edge. The slopes of the spikes are all at least -20 MPa/100 pm, or about -0.2 MPa/pm. In other words, the slopes of the spike have an absolute value of 0.2 MPa/pm or greater, and the slope is in the direction of greater compressive stress. If the samples were subsequently annealed, the slope would be less.

[0152] For Samples 7C and 7D, the maximum deviations from 0 are residual stress values of about -45 MPa and -65 MPa (each compressive stress) occurring within the sample very near the edge - from the edge to a depth of about 100 pm into the sample as part of the spike in residual compressive stress. For Sample 7E, the maximum deviation from 0 is a residual stress value of about 20 MPa (tensile) occurring about 800 pm from the edge, although a compressive stress spike does occur at the edge and into a depth of about 100 pm from the edge. For Sample 7B, the maximum deviation from 0 is either a residual stress value of about 20 MPa (tensile) occurring about 200 pm from the edge or the -20 M Pa (compressive) stress occurring very near the edge as part of the compressive stress spike. For all of Samples 7B- 7D, the residual stress has dissipated after about 600 pm from the edge, with the values hovering right around 0 (- or + 5 MPa).

[0153] Example 8 - For Example 8, samples of a glass article having an alkaline earth aluminoborosilicate glass composition were prepared. The edges of the samples were then treated with atmospheric-pressure plasma according to the present disclosure. For Samples 8A1 and 8A2, the plasma was generated from hydrogen and nitrogen gasses. The difference between Sample 8A1 and Sample 8A2 is the speed at which the edge moved relative to the plasma, with Sample 8A2 being faster. For Samples 8B1 and 8B2, the plasma was generated from helium and nitrogen gasses. The difference between Sample 8B1 and Sample 8B2 is the speed at which the edge moved relative to the plasma, with Sample 8B2 being faster. Each sample was then subjected to secondary ion mass spectrometry to determine the atomic density of various elements as a function of position from the edge. The results are reproduced at FIG. 25A for Sample 8A, and at FIG. 25B for Sample 8B. The y-axis for each element is the same - atoms per cubic centimeter. The x-axis for each element is the same - distance from the edge (in nm). An untreated sample was also tested and reported, as a control.

[0154] The graphs reveal that treating the edge with the atmospheric-pressure plasma treatment only minimally alters the composition of the glass article and whatever alteration that does occur (e.g., for Mg, Ca, Al, and Sr for Samples 8A1-2 using hydrogen gas plasma) occurs within 25 nm or so from the edge. The only exception appears to be a depletion in boron that occurs when helium gas is partially utilized to generate the plasma at Samples 8B1- 2. Whether the speed of the plasma treatment is relatively fast or relatively slow does not make a major difference.

[0155] Example 9 - For Example 9, a samples of an alumino boro silicate alkali-free glass were prepared, a Sample 9A and a Sample 9B. The samples had a thickness of 98.62 pm (0.09862 mm). The samples was scored and separated from a larger workpiece. The edge of Sample 9A was not treated. Optical microscope images of Sample 9A were captured, including a cross-sectional view and an elevational view. The images are reproduced at FIG. 26, with the cross-sectional view at the top left and the elevational view at the bottom left. The imperfections from the scoring to obtain Sample 9A is visually apparent in the elevational view (bottom left).

[0156] In contrast, the edge of Sample 9B was treated with an atmospheric-pressure plasma according to the present disclosure. After the plasma treatment, the same images of Sample 9B were captured and the images reproduced at FIG. 26. The elevational view of Sample 9B shows that the plasma treatment of the edge eliminated the imperfections from the scoring that are apparent in the image of Sample 9A. This example further demonstrates that atmospheric-pressure plasma can remove flaws at the edge of a relatively small glass article having a thickness of about 0.1 mm or less.

[0157] Example 10 - For Example 10, five samples (Samples 10A-10E) were obtained from a common workpiece of an alumino boro silicate alkali-free glass, and all samples had a thickness of 0.1 mm. Sample 10A was maintained as a control and the edge thereof was not treated with atmospheric-pressure plasma. The edges of each of Samples 10B-10E were treated with atmospheric-pressure plasma under varying conditions, as set forth in Table 1 below. The plasma for each of Samples 10B-10E was generated from nitrogen, argon, and hydrogen gasses having a a total flow rate of 35 slm, as set forth in the second row, and with only one scan pass. The relative flow ratio of the gasses from which the plasma was formed is set forth in the third row. For example, the plasma that treated the edge of Sample 10B was formed from nitrogen, argon, and hydrogen gasses with a flow rate ratio of 90:3:7 respectively. The power that generated the plasma for each sample is set forth in the fourth row. For example, the plasma that treated the edge of Sample 10B was generated at a power of 470 W. The scan speed for the plasma treatment of each sample is set forth in the fifth row. For example, the edge of Sample 10B was treated with plasma moving relative to the edge at a rate of 20 mm/second. The gap distance between the head delivering the plasma and the edge of the sample is set forth in the sixth row. For example, the gap distance for the plasma treatment of Sample 10B was 9 mm.

Table 1

[0158] After the plasma treatments, a scanning electron microscope was utilized to capture an image of each of the edges of the samples. A sample of the images are reproduced at FIG. 27A, with the image of the edge for Sample 10A (the control) is reproduced at the top left, the image of the edge for Sample 10B (plasma treated) is reproduced at the top right, and the image of the edge for Sample 10C (plasma treated) is reproduced at the bottom. The imperfections at the from the separation process to obtain Sample 10A is visible. The imperfections are much less visible in the image of the edge of Sample 10B, illustrating that plasma treatment lessens or removes such perfections and decreases the surface roughness. Finally, the imperfections are not noticeable in the image of the edge of Sample 10C, illustrating that the plasma treatment can eliminate the imperfections at the edge and leave an edge without visible surface roughness.

[0159] Next, each of the samples were subjected to a two point bend test. A Weibull distribution graph was prepared. The graph is reproduced at FIG. 27B. The BIO values for each sample is reproduced above in the last row of Table 1. The control Sample 10A without a plasma treated edge had a BIO value of 198 MPa, while the plasma-treated Samples 10B- 10E all had a BIO value of greater than 300 MPa, with Sample 10C having a BIO value of 468 MPa.

Claims

CLAIM(S) What is claimed is:

1. A glass article comprising: a first primary surface; a second primary surface that faces in a generally opposite direction than the first primary surface; a thickness between the first primary surface and the second primary surface that is within a range of from 0.095 mm to 3.5 mm; and an edge transitioning the first primary surface to the second primary surface; wherein, the edge exhibits a surface roughness (Ro) within a range of from 30 nm to 110 nm, wherein, a density of particles upon the edge is less than 2 particles per 0.1 square millimeter, wherein, the glass article exhibits a residual stress at or near the edge that has a maximum deviation from O that is within a range of from -100 MPa to 40 MPa, where negative values are compressive stress and positive values are tensile stress; and wherein, one of the following conditions are satisfied:

(i) the glass article further comprises one or more regions of compressive stress contiguous with one or more of the first primary surface and the second primary surface, and upon being subjected to a four-point flexural test according to ASTM C158, the glass article exhibits a BIO Weibull distribution flexural stress value within a range of from 700 MPa to 900 MPa; or

(ii) the glass article lacks a region of compressive stress, and upon being subjected to the four-point flexural test according to ASTM C158, the glass article exhibits a B10 Weibull distribution flexural stress value that is greater than or equal to 300 MPa.

2. The glass article of claim 1 further comprising: one or more regions of compressive stress contiguous with one or more of the first primary surface and the second primary surface, wherein, upon being subjected to the four-point flexural test according to ASTM C158, the glass article exhibits a BIO Weibull distribution flexural stress value within a range of from 700 MPa to 900 MPa.

3. The glass article of claim 1, wherein the glass article lacks a region of compressive stress, and upon being subjected to the four-point flexural test according to ASTM C158, the glass article exhibits a BIO Weibull distribution flexural stress value that is greater than or equal to 300 MPa.

4. The glass article of any one of claims 1-3, wherein the first primary surface and the second primary surface each comprise a non-planar portion.

5. The glass article of any one of claims 1-4, wherein the glass article is a component of an interior of a vehicle or a consumer electronic device.

6. The glass article of any one of claims 1-5, wherein the glass article is selected from the group consisting of: a borosilicate glass, an alumino boro silicate alkali-free glass, an aluminoborosilicate glass, an alkaline earth aluminoborosilicate glass, high purity fused silica, an alkali-containing glass, a glass that includes one or more rare earth oxides, a non-silicate glass, a borate glass, a boroaluminate glass, a phosphate glass, a germanate glass, a fluorophosphate glass, a sulfophosphate glass, a vanadate glass, and a glass-ceramic.

7. The glass article of any one of claims 1-6 further comprising: a chamfer portion transitioning between the edge and the first primary surface.

8. The glass article of any one of claims 1-6, wherein the edge provides an entirely curved transition from the first primary surface to the second primary surface.

9. The glass article of any one of claims 1-8, wherein the maximum deviation from 0 of the residual stress at or near the edge is disposed at a position within the glass article that is within 1000 pm from the edge, and the residual stress within the glass article at positions 1800 pm from the edge and further into the glass article is within a range of from -5 MPa to 5 MPa.

10. The glass article of any one of claims 1-9, wherein the residual stress at the edge and to a distance of at least 100 pm into the glass article from the edge is compressive.

11. The glass article of any one of claims 1-10, wherein the residual stress as a function of distance from the edge into the glass article has a slope, at least a portion of the slope has an absolute value of 0.2 MPa/pm or greater, and the portion of the slope is directed towards greater compressive stress.

12. The glass article of claim 11, wherein the portion of the slope occurs within 100 pm into the glass article from the edge.

13. The glass article of any one of claims 1-12, wherein a number of atoms per volume of one or more of Mg, Ca, Al, and Sr is substantially constant at all positions within the glass article from 30 nm from the edge to 200 nm from the edge.

14. The glass article of any one of claims 1-13, wherein the glass article exhibits a residual stress at or near the edge that has a maximum deviation from 0 that is within a range of from -70 MPa to -20 MPa, where negative values are compressive stress.

15. The glass article of any one of claims 1-14, wherein the glass article has not been subjected to an annealing procedure.

16. A method of treating a glass article comprising: contacting an edge of a glass article with an atmospheric-pressure plasma generated from gas while moving at least one of the glass article and the atmospheric-pressure plasma relative to the other; and imparting additional heat to one or both of a first primary surface and a second primary surface proximate the edge of the glass article simultaneously with contacting the edge of the glass article with the atmospheric-pressure plasma.

17. The method of claim 16 further comprising: before contacting the edge of the glass article with the atmospheric-pressure plasma, grinding or laser-cutting the edge.

18. The method of any one of claims 16-17 further comprising: after contacting the edge with the atmospheric-pressure plasma, subjecting the glass article to an ion-exchange procedure resulting in one or more regions of compressive stress within the glass article.

19. The method of claim 18, wherein after the edge of the glass article is contacted with the atmospheric-pressure plasma and after subjecting the glass article to the ion-exchange procedure, upon being subjected to a four-point flexural test according to ASTM C158, the glass article exhibits a BIO Weibull distribution flexural stress value within a range of from 700 MPa to 900 MPa.

20. The method of any one of claims 16-19, wherein after the edge of the glass article is contacted with the atmospheric-pressure plasma, upon being subjected to a four-point flexural test according to ASTM C158, the glass article exhibits a B10 Weibull distribution flexural stress value that is greater than or equal to 300 MPa.

21. The method of any one of claims 16-20, wherein a laser, a heat lamp, or a second atmospheric-pressure plasma is utilized to impart the additional heat.

22. The method of any one of claims 16-21, wherein after contacting the edge with the atmospheric-pressure plasma and after imparting the additional heat to the to the glass article, the glass article exhibits a residual compressive stress at or near the edge that has a maximum deviation from 0 that is within a range of from -80 MPa to 40 MPa, where negative values are compressive stress and positive values are tensile stress.

23. The method of any one of claims 16-22, wherein the atmospheric-pressure plasma is generated from one or more of nitrogen gas, compressed dry air gas, helium gas, argon gas, and hydrogen gas.

24. The method of any one of claims 16-23, wherein the atmospheric-pressure plasma contacts the edge at an angle other than perpendicular to the edge.

25. The method of any one of claims 16-24, wherein the contacting the edge of the glass article with the atmospheric-pressure plasma generates a first chamfer portion that transitions the edge to the first primary surface.

26. The method of any one of claims 16-24, wherein the contacting the edge of the glass article with the atmospheric-pressure plasma generates (i) a first chamfer portion that transitions the edge to the first primary surface and (ii) a second chamfer portion that transitions the edge to the second primary surface.

27. The method of any one of claims 16-26, wherein the contacting the edge of the glass article with the atmospheric-pressure plasma generates a curved surface at the edge.

28. The method of any one of claims 16-27, wherein contacting the edge of the glass article with the atmospheric-pressure plasma comprises simultaneously contacting the edge with more than one atmospheric-pressure plasmas such that heat generated by any two adjacent plasma jets at least partially overlaps.

29. The method of any one of claims 16-28, wherein the first primary surface and the second primary surface each comprise a non-planar portion.

30. The method of any one of claims 16-29, wherein the glass article is selected from the group consisting of: a borosilicate glass, an alumino boro silicate alkali-free glass, an aluminoborosilicate glass, an alkaline earth aluminoborosilicate glass, high purity fused silica, an alkali-containing glass, a glass that includes one or more rare earth oxides, a non-silicate glass, a borate glass, a boroaluminate glass, a phosphate glass, a germanate glass, a fluorophosphate glass, a sulfophosphate glass, a vanadate glass, and a glass-ceramic.

31. The method of any one of claims 16-30, wherein after contacting the edge with the atmospheric-pressure plasma and after imparting the additional heat to the to the glass article, the edge exhibits a surface roughness (Ro) within a range of from 30 nm to 110 nm.

32. The method of any one of claims 16-31, wherein after contacting the edge with the atmospheric-pressure plasma and after imparting the additional heat to the to the glass article, the glass article further comprises particles upon the edge, and a density of the particles upon the edge is less than 2 particles per 0.1 square millimeter.

33. The method of any one of claims 16-32, wherein the glass article comprises a thickness that is within a range of from 0.095 mm to 3.5 mm.

34. The method of any one of claims 16-33, wherein the at least one of the glass article and the atmospheric-pressure plasma move relative to the other at a speed within a range of from 20 mm/second to 200 mm/second.

35. The method of any one of claims 16-33, wherein the at least one of the glass article and the atmospheric-pressure plasma move relative to the other at a speed that is greater than or equal to 20 mm/second.

36. The method of any one of claims 16-35, wherein the glass article is not subjected to an annealing procedure, after contacting the edge with the atmospheric-pressure plasma and imparting additional heat to one or both of the first primary surface and a second primary surface proximate the edge.

37. The method of any one of claims 16-36, wherein imparting the additional heat to one or both of the first primary surface and the second primary surface proximate the edge simultaneously with contacting the edge of the glass article with the atmospheric-pressure plasma causes the residual tensile stress at or near the edge to transition to no residual stress or residual compressive stress.

38. A system to treat an edge of a glass article comprising: a support configured to support a glass article that has an edge; and a first head configured and positioned to emit atmospheric-pressure plasma onto the edge of the glass article; wherein, one or both of the support and the first head are movable relative to the other.

39. The system of claim 38 further comprising: a second head configured and positioned to emit atmospheric-pressure plasma onto the edge of the glass article, with the heat of the plasma from the first head at least partially overlapping the heat of the plasma from the second head.

40. The system of any one of claims 38-39 further comprising: one or more heat emitters positioned relative to the support to emit heat onto one or both of a first primary surface and second primary surface of the glass article near where the first heat emits plasma onto the edge of the glass article.

41. The system of claim 40, wherein the one or more heat emitters comprise one or more of a laser source, a lamp, or a head configured to emit atmospheric-pressure plasma.

42. The system of any one of claims 38-41, wherein the first head is positioned relative to the support to emit plasma generally orthogonal to the edge of the glass article.

43. The system of any one of claims 38-41, wherein the first head is positioned relative to the support to emit plasma at an angle between

(i) orthogonal to a first primary surface of the glass article and (ii) orthogonal to the edge of the glass article.

44. The system of any one of claims 38-43, wherein the first head comprises (i) a slot configured to accept the edge of the glass article and

(ii) a plurality of apertures at the slot positioned to emit plasma onto at least two of a first primary surface of the glass article, the edge of the glass article, and a second primary surface of the glass article.

45. The system of claim 44, wherein the slot of the first head is arc-shaped.

46. The system of any one of claims 38-45, wherein one or both of the support and the first atmospheric-pressure plasma emitter are movable relative to the other at a rate that is greater than or equal to 20 mm/second.