FR3011197A1 - WEAR RESISTANT COATING - Google Patents

Abstract

A brazing cable (10) is described herein to form a wear-resistant coating on a substrate by a brazing process, the brazing cable comprising a mixture (12) comprising a plurality of round particles (24), a binder of wear-resistant coating for connecting the plurality of round particles (24) in the wear-resistant coating when formed, and a temporary binder which connects the mixture, each of the plurality of round particles (24) comprises a rounded outer layer (28) encapsulating a wear resistant member (26). Also described herein is a method for making a brazing cable to form a wear-resistant coating on a substrate by a brazing process, a wear-resistant coating on a substrate, and a method for forming a coating resistant to wear. wear on a substrate.

Description

TECHNICAL FIELD The present description generally, but not exclusively, relates to a brazing cable for forming a wear-resistant coating on a substrate by a brazing process, a method for making a brazing cable. in order to form a wear-resistant coating on a substrate by a brazing process, a wear-resistant coating on a substrate and a method for forming a wear-resistant coating on a substrate. Background of the Invention Refilling is a process of applying a wear resistant material to a surface to improve the wear properties of the surface or to repair the surface. Reloading is currently used compared to industrial, excavation and drilling tools, for example. Generally, there is a long-felt need for better, wear-resistant, tougher and more consistent materials that can be relatively easily applied. SUMMARY A first aspect of the invention is to provide a brazing cable for forming a wear-resistant coating on a substrate by a brazing process. The brazing cable comprises a blend comprising a plurality of round particles, a wear-resistant coating binder for bonding the plurality of round particles in the wear-resistant coating when formed, and a temporary binder which 35 binds the mixture. Each of the plurality of round particles comprises a rounded outer layer encapsulating a wear resistant member. Generally, the rounded outer layer of each of the plurality of round particles controls the spacing and / or compaction of the wear-resistant members of the plurality of round particles within the wear-resistant coating, when it is applied. The rounded outer layer of each of the plurality of round particles can control the spacing and / or compaction of the wear resistant members of the plurality of round particles within the brazing cable. Therefore, the thickness of the rounded outer layer can be chosen to control the number of wear resistant elements per unit volume of the wear resistant coating. The thickness of the rounded outer layer may be selected to control the uniformity of distribution of the wear-resistant members within the wear-resistant coating.

In the context of this document, the temporary binder comprises a bonding substance that allows the mixture to escape during the brazing process. The temporary binder usually binds the mixture so that it can maintain the shape of the cable.

An embodiment includes a line that is disposed in the mixture. The line can be embedded in the mixture. The mixture can be attached to the line. The line can be arranged centrally inside the cable. Alternatively, the line may be offset from the center of the cable. The line may comprise at least one of iron, nickel and any other suitable material. The line may comprise, for example, one of a wire and a braided cord. Alternatively, the line may comprise any suitable material, examples of which include nylon and other polymers. In one embodiment, for each of the plurality of round particles, the rounded outer layer 5 has a density greater than that of the wear resistant member. Therefore, the plurality of round particles float less in the melt-resistant coating binder during the brazing process than a plurality of wear-resistant members without circular outer coatings. The distribution of the elements in the wear-resistant coating can therefore be better than if the rounded outer layers were absent. In one embodiment, the wear-resistant coating binder may comprise a metal-wear-resistant coating binder. The metal wear resistant coating binder may comprise a plurality of metal particles. The plurality of metal particles may comprise a brazing metal. The brazing metal may comprise a solder alloy. In one embodiment, the volume fraction of the plurality of round particles within the mixture is at least 0.05. The volume fraction of the plurality of round particles within the mixture may be no greater than 0.85. In one embodiment, the wear-resistant member of each of the plurality of round particles has an ISO 6106 mesh size of at least 18. The wear resistant member of each of the plurality of particles rounds may have an ISO 6106 mesh size of no greater than 120. In an alternative embodiment, the wear resistant member of each of the plurality of round particles may have an ISO 6106 mesh size of no greater than In one embodiment, the rounded outer layer comprises a composite material. The composite material may be a cermet. The cermet may be a polycrystalline cermet. In one embodiment, the wear resistant member of each of the plurality of round particles comprises a material having a Vickers hardness greater than at least one of 20 GPa and 40 GPa. Wear-resistant elements having a Vickers hardness greater than 40 GPa are, in the context of this document, super hard materials. In one embodiment, each of the plurality of round particles has a modulus of elasticity greater than 200 GPa. In one embodiment, the plurality of round particles has a compact arrangement. In one embodiment, the blend comprises another plurality of particles that occupy a plurality of interstices between the plurality of round particles. The other plurality of particles may be rounded. The other plurality of particles may comprise a first plurality of particles having a first average diameter and a second plurality of particles having a second average diameter that is smaller than the first average diameter. The second average diameter may be less than 10% of the first average diameter. The second plurality of particles may further increase the volume fraction of particles within the wear resistant coating as it is formed, which can improve the wear resistance of the wear resistant coating. . In one embodiment, the wear-resistant member of each of the plurality of round particles has a metallurgically bonded coating thereto, the coating being metallurgically bondable to the bond-resistant coating binder. wear.

A second aspect of the invention provides a method for making a brazing cable to form a wear-resistant coating on a substrate by a brazing process. The method comprises the step of forming a blend comprising a plurality of round particles, a wear-resistant coating binder, and a temporary binder that binds the blend. Each of the plurality of round particles comprises a rounded outer layer encapsulating a wear resistant member. The method comprises the step of extending the mixture. In one embodiment, the step of extending the mixture comprises the step of configuring the mixture into a cable form. In one embodiment, the step of extending the mixture comprises the step of arranging the mixture along a line by simultaneously extruding the mixture through a die and stretching the line through the sector. The step of extending the mixture may include the step of fixing the mixture along the line. The step of extending the mixture may include the step of drowning the line within the mixture. One embodiment comprises the step of compressing the mixture. The step of extruding the mixture may include the step of extruding the thus compressed mixture. In one embodiment, the step of extending the mixture comprises the step of rolling the mixture. The step of rolling the mixture may include the step of rolling the mixture around a line. In one embodiment, for each of the plurality of round particles, the outer round layer 5 has a density greater than that of the wear resistant member. In one embodiment, the wear-resistant coating binder comprises a metal-wear-resistant coating binder. The metal wear resistant coating binder may comprise a plurality of metal particles. The wear resistant coating binder material may comprise a solder metal. The brazing metal may comprise a solder alloy. In one embodiment, the volume fraction of the plurality of round particles in the mixture is at least 0.05. The volume fraction of the plurality of round particles in the mixture may be no greater than 0.85. In one embodiment, the rounded outer layer comprises a composite. The composite can be a cermet. The cermet may be a polycrystalline cermet. In one embodiment, the wear-resistant member of each of the plurality of round particles has an ISO 6106 mesh size of at least 18. The wear-resistant member of each of the plurality of round particles may have an ISO 6106 mesh size of no more than 120. The wear-resistant member 30 of each of the plurality of round particles may have an ISO 6106 mesh size of no greater than 80. In one embodiment the wear resistant member of each of the plurality of round particles comprises a material having a Vickers hardness greater than at least one of 20 GPa and 40 GPa. In one embodiment, each of the plurality of round particles has a modulus of elasticity greater than 200 GPa. In one embodiment, the step of forming the mixture comprises the step of including in the mixture another plurality of particles that occupies a plurality of interstices between the plurality of round particles. The other plurality of particles may be rounded. The other plurality of particles may comprise a first plurality of particles having a first average diameter and a second plurality of particles having a second average diameter which is smaller than the first average diameter. The second average diameter may be less than 10% of the first average diameter. The second plurality of particles may further increase a volume fraction of particles. In one embodiment, the wear-resistant member of each of the plurality of round particles has a metallurgically bonded coating thereto, the coating being metallurgically bondable to the liner-resistant coating binder. 'wear. A third aspect of the invention provides a wear resistant coating on a substrate. The wear-resistant coating comprises a plurality of round particles connected together by a wear-resistant coating binder, each of the plurality of round particles comprising a rounded outer layer encapsulating a wear-resistant member. In one embodiment, the plurality of round particles has a compact arrangement. The wear resistant coating may comprise another plurality of particles that occupy a plurality of interstices between the plurality of round particles. In one embodiment, the wear-resistant coating binder comprises a metal-wear-resistant coating binder. The metal wear resistant coating binder may comprise a solder metal. The brazing metal may comprise a solder alloy. The wear resistant coating binder may comprise a monolithic matrix of the metal wear resistant coating binder. In one embodiment, the wear-resistant coating binder penetrates the rounded outer layer of each of the plurality of round particles. In one embodiment, the wear-resistant member of each of the plurality of round particles has a metallurgically bonded coating thereto, the coating being metallurgically bondable to the bond-resistant coating binder. wear. The coating can be metallurgically bonded to the wear-resistant coating binder. In one embodiment, the wear-resistant coating binder is metallurgically bonded to one of an inner surface and an outer surface of the rounded outer layer of each of the round particles. A fourth aspect of the invention provides a wear-resistant coating on a substrate, the wear-resistant coating comprising: a composite material comprising a plurality of round particles connected together by a wear-resistant coating binder wherein each of the plurality of round particles comprises a particle-resistant layer 911, wherein the wear-resistant coating binder is metallurgically bonded to at least one of an inner surface and an outer surface of the rounded outer layer 10 of each of the plurality of round particles. In one embodiment, the binder of a material of 15 may comprise a monolithic matrix of the metal bonding material. The metal bonding metal bonding material. A fifth aspect of the invention provides a method for forming a wear resistant coating on a substrate. The method comprises the step of heating a brazing cable as described above to melt the wear-resistant coating binder. The method comprises the step thus melted on a surface of the substrate. In one embodiment, the wear resistant coating thus formed may be in accordance with at least one of the third aspect of the invention and the fourth aspect of the invention. . Any of the various features of each of the above descriptions and the various features of the embodiments described below may be combined where appropriate and desired. With a rounded outer surface encapsulating a wear resistant member, the wear resistant coating binder penetrates the rounded outer layer and is metallurgically bonded to a metallurgically bonded coating each of the plurality of resistant coating members. The embodiments are now described by way of example only with reference to the accompanying drawings, in which: Figure 1 shows a section through a length of one embodiment of the present invention; a brazing cable. Figure 2 schematically shows a detail of a mixture within a brazing cable of Figure 1. Figure 3 shows a section of a representative particle of a plurality of round particles in the mixture of Figure 2. Figure 4 is a backscattered scanning electron micrograph of an encapsulant. Figure 5 is a backscattered scanning electron micrograph of a fracture through one of the plurality of round particles. Figure 6 shows a plurality of round particles. Figures 7 to 9 show diagrams in which the interstices of a plurality of round particles are occupied by another plurality of particles. Figure 10 shows a flowchart for a method of making the brazing cable of Figure 1. Figure 11 shows a cylinder of the mixture of Figure 2. Figure 12 shows an example of the extruder 30. Figure 13 shows a micrograph of a wear resistant material made using the brazing cable of Figure 1 in a brazing process. DESCRIPTION OF THE EMBODIMENTS FIG. 1 shows a section taken through a length of one embodiment of a brazing cable generally indicated by reference numeral 10. Brazing cable 10 is provided to form a tough coating to wear on a substrate by a brazing process. The brazing cable 10 comprises a mixture 12. Figure 2 schematically shows a detail of the mixture 12. The mixture 12 has a plurality of round particles 24. The mixture 12 has a wear-resistant coating binder 25 to bind the plurality of round particles in the wear-resistant coating when formed. In this embodiment, but not necessarily in all embodiments, the wear-resistant coating binder 25 comprises a plurality of wear-resistant coating binder particles 25. The binder of the blend is a temporary binder 16. Each of the plurality of round particles 24 comprises a rounded outer layer 28 encapsulating a wear resistant member 26. In this embodiment, but not necessarily in all embodiments, the solder wire 10 includes a line in the form of a nickel wire 13. The line may take any suitable form, for example, include a length of nylon or polymer bead. The line may include iron. The line may include a braided cord.

In an example of a brazing process, a surface of a steel substrate is optionally cleaned by applying a grinding wheel. Alternatively, a chemical cleaning agent or generally any suitable cleaning process may be used. A flame, for example, an oxyacetylene flame, may then optionally be applied to the substrate to preheat it. The tip 11 of the brazing cable 10 is then placed on the preheated surface and inside the flame. Then, the tip of the brazing cable 10 is heated so that the temporary binder escapes (for example, by decomposition, combustion and / or evaporation) and the tip of the cable 11 and the wear-resistant coating binder melt to form a fluid in the form of a molten brazing cable. The fluid and the particles within it flow over the surface of the substrate. The fluid solidifies upon cooling to form a wear resistant coating comprising the plurality of round particles distributed in and bonded by the wear resistant coating binder. By diffusion, the wear-resistant coating is atomically bonded to the surface of the substrate. Generally, any suitable brazing process can be used, for example, alternatively internal gas tungsten welding techniques can be used. In this embodiment, but not necessarily in all embodiments, the wear-resistant coating binder is heated until it melts completely. The fully melted wear-resistant coating binder is different from the partially melted wear-resistant coating binder and the simply softened wear-resistant coating binder. For the partially melted wear-resistant coating binder, only a portion (e.g., the edges or the outer layer) of the plurality of particles of the bonding material may be melted. The wear-resistant coating binder thus completely melted penetrates a plurality of interstices between the plurality of round particles and after cooling forms a matrix in the form of a monolithic matrix which connects the plurality of round particles. Filling the interstices with the wear-resistant coating binder improves the strength of the resulting composite and therefore the strength of the wear-resistant surface. The bonding material may also, as in this embodiment, form a metallurgical bond with interstitial particles that may be included. The rounded outer layer of each of the plurality of round particles may generally comprise a porous or skeletal structure, wherein the inner surfaces define voids and / or internal passageways. The wear-resistant coating binder penetrates the porous or skeletal structure and can fill the voids and / or internal passageways, to form a web within the outer layer rounded by at least a majority. of the plurality of round particles. This results in a strong mechanical attachment to the plurality of round particles. In the wear-resistant coating, when formed, the wear-resistant coating binder can, as in the present embodiment, penetrate the intermediate coating of the elements 26 and the encapsulating material. . The wear-resistant coating binder is metallurgically bonded to the intermediate coating of the element 26 and encapsulating material. Therefore, the wear-resistant members in this embodiment of the diamonds are metallurgically bonded to the wear resistant coating binder by means of the intermediate coating 30. This can generally improve the fastening of the elements. These wear-resistant elements, particularly when exposed to wear, and the simple mechanical fastening may be insufficient for their retention in the coating. This can improve the performance and service life of the wear-resistant coating. The solidified wear-resistant coating binder is, in this embodiment, but not necessarily in all embodiments, also metallurgically bonded to the plurality of round particles (which may include metal), outer surfaces of the plurality of round particles and at the inner surfaces of the plurality of round particles. This can further increase the strength of the rod and the final wear-resistant coating. The metallurgical bonds described herein may include diffused atoms and / or atomic interactions. Under such conditions, the component parts can be "wetted" onto and through the bonding material. In other embodiments, however, the wear-resistant coating binder is simply softened by heating to provide a bonding effect.

The substrate may generally be any suitable substrate, examples of which include a drill used by the mining industry or another industry, other downhole equipment, the teeth of a bucket for an excavator, a chisel and a blade. For solder wire 10 of FIG. 1, but not necessarily for all embodiments of a brazing cable, the rounded outer layer 28 has a higher density than that of the wear-resistant member 26. The average density of the plurality of round particles 24 is greater than the average density of the wear-resistant members 26. In the case of raw or individual wear-resistant members, then they can float upwardly in the melt-resistant coating binder during the brazing process, which results in an irregular concentration of the wear resistant elements in the wear-resistant coating, which is generally undesirable. In this embodiment, the rounded outer layer is a composite in the form of a cermet, with a theoretical density generally of the order of 15-19 gcm-3. The cermet comprises cobalt. Cobalt has a density of about 8.9 g.cm-3. The wear resistant member is a diamond having a density of about 3.5 g. cm-3. The wear-resistant coating binder may, for example, be generally any suitable brazing metal, including copper, tin, silver, cobalt, nickel, cadmium, manganese, zinc or their alloy. The metal particles may also include chromium which hardens the alloy formed upon solidification of the molten brazing cable. The wear-resistant coating binder may also contain silicon and / or boron powder to aid melting and deposition characteristics. In the present embodiment, the wear-resistant coating binder comprises nickel, chromium, boron, and silicon. Nickel can constitute from 88% to 95% by weight, chromium can constitute from 0% to 12%, boron can constitute from 0% to 1% and silicon can constitute from 0% to 1%. FIG. 3 shows a section of a representative particle 24 of the plurality of round particles, the wear resistant member being indicated by reference numeral 26 and the rounded outer layer ("the encapsulant") being indicated by the reference numeral 28. The wear-resistant member 26 is, in this embodiment, a super hard material, which is conventionally understood to be a material having a Vickers hardness greater than 40 GPa. Examples of super hard materials that can be used include, but are not limited to, synthetic diamond, natural diamond, and cubic boron nitride. However, alternative embodiments do not have elements including the super hard material. The element in this embodiment has an indentation resistance greater than 20 GPa and a modulus of elasticity greater than 200 GPa. The element can be crystalline or polycrystalline. Other examples of suitable wear resistant member materials include silicon-reactive polycrystalline diamond, catalyst-free polycrystalline diamond, alumina, partially stabilized zirconia, silicon carbide, and silicon nitride. Generally, but not necessarily, wear-resistant members with a Vickers hardness exceeding 20 GPa can be used. Element 26, in this embodiment, but not in all embodiments, is synthetic diamond. The element typically has a relatively low density of less than 6 g. cm-3. In this embodiment, but not necessarily in all embodiments, the rounded outer layer 28 comprises a polycrystalline cermet in the form of tungsten carbide particles sintered with cobalt particles. A cermet is generally a composite material composed of ceramic particles (examples of which include an oxide, a boride or a carbide) bonded together with a metallic material (eg, nickel, molybdenum and cobalt). The encapsulant 28 is different from the wear resistant member 26 in that, in this embodiment, but not necessarily in all embodiments, it has a lesser hardness. The encapsulant is, in this embodiment, but not necessarily in all embodiments, polycrystalline and before its brazing cable manufacture, may be present in different forms such as having adjacent non-reactive shaving grains and unbound, completely sintered with measurable porosity from low to zero. Alternatively, the rounded outer layer 28 may comprise a metal matrix composite, for example tungsten or polycrystalline molybdenum in a metal binder such as cobalt, nickel or iron. FIG. 4 is a backscattered scanning electron micrograph of the encapsulant 28. In this micrograph, the polycrystalline material, in this case tungsten carbide 44, has sintered and connected neighboring grains. A sintering aid material, in this case cobalt 46, was partially softened by heating during the formation of the plurality of round particles to form the encapsulant or pellet and thus "bridged" or assembled with it and in polycrystalline material 44. In this particular example, the structure is not completely densified and voids or holes 48 are present within the structure. A semi-porous structure, with small pores that provide high capillary forces, may be advantageous in terms of metallurgical bonding during the brazing process. The density levels of the material used to form the grains in the encapsulant are higher than those of the superhard element (> 6g.cm-3). The density and overall hardness of the encapsulant depend on the material used and the degree of sintering. Regardless of the degree of sintering, the encapsulant greatly increases the density of the plurality of round particles. In the case where sintering is necessary, metals can be used in powder form as sintering aid. Examples of the materials used in the polycrystalline material include, but are not limited to, tungsten and tungsten carbide. Examples of sintering aids that can be used include, but are not limited to, cobalt, nickel and iron. The methods used to encapsulate the elements in the encapsulant generally, but not necessarily, encourage high degrees of sphericity, even when the elements are not circular or spherical in nature, for example, cuboidal, acicular or elliptical. The majority of pellets used (> 50%) contain one element. The majority (> 50%) of the elements are encapsulated in the encapsulant, so there may be a minority of examples (<50%) in which the element is not encapsulated at all by the encapsulant. In the examples of Figures 1 and 2, but not necessarily in all the examples, the element 26 is metallurgically connected to an intermediate coating of the element 26 and the encapsulating material 28. The coating can be deposited using different techniques, including, but not limited to, chemical vapor deposition, physical vapor deposition and metallization. Such techniques provide a coating which is generally of the order of one to a few microns in thickness; for example 1 to 2 microns. Examples of coating materials include, but are not limited to, titanium and silicon, where element 26 is a diamond.

FIG. 5 is a backscattered scanning electron micrograph of a fracture through particle 24. The disclosed intermediate coating of elements 26 and encapsulating materials is, in this embodiment, but not necessarily in all modes of realization, a metal coating comprising titanium. In the micrograph of Figure 5, the titanium 30 which completely completely surrounds the element 26 and is connected thereto, has been partially removed on the fracture. The opposite surface or fracture pocket (not shown) contains remnants of the titanium, indicating the equivalent metallurgical bond between the titanium and the element and the titanium and the encapsulant. The volume of the coating is significantly less (generally, but not necessarily less than 1/100) that of the element 26. The effect of the coating 30, in this embodiment, but not necessarily in all embodiments does not contribute much to the overall density of the element 26. The coating 30 can provide a stronger bond between the element 26 and the encapsulation material 28, together with the thermal and chemical protection of the element 26 during the manufacture and use of the brazing cable.

Figure 6 shows a plurality of round particles. A majority of round particles 24 in this embodiment, but not necessarily in all embodiments, each have a diameter between 70% and 130% of an average diameter of the plurality of round particles. In other embodiments, the majority of the plurality of round particles may each have a diameter of between 80% and 120% of an average diameter of the plurality of round particles. In yet other embodiments, the majority of the plurality of round particles may each have a diameter of between 90% and 110% of an average diameter of the plurality of round particles. In yet other embodiments, the majority of the plurality of round particles may each have a diameter between 95% and 105% of an average diameter of the plurality of round particles. Applicants believe that the smaller the diameter distribution, the less a compact structure of the plurality of round particles will have defects and the better will be the performance of the wear resistant coating. Bulk material or powder (hereinafter referred to as "powder") comprising a plurality of round particles having a narrow diameter distribution may, however, be relatively more expensive to produce. Figure 7 shows a diagram in which the interstices of a plurality of round particles in a brazing cable (or wear-resistant coating formed using the brazing cable) are occupied by another plurality of particles, The temporary binder and the wear-resistant coating binder are omitted for the sake of clarity. Each of the other plurality of particles has an element 34 of superhard material encapsulated by an encapsulant 36, as described herein, with respect to the plurality of particles. Fig. 8 is a diagram in which the interstices of a plurality of round particles, such as at reference numeral 25, in a brazing cable (or a wear resistant coating formed using the brazing cable). are occupied by the other plurality of particles, such as at reference numeral 38, which have no encapsulant. The temporary binder and the wear-resistant coating binder are omitted for the sake of clarity. In this case, but not necessarily in all cases, the other plurality of particles is harder than the encapsulant. Fig. 9 is a diagram in which the interstices of a plurality of round particles in a brazing cable (or a wear-resistant coating formed using the brazing cable), as in reference numeral 25, are occupied by the other plurality of particles which comprises a first plurality of particles, such as particle 40 having a first average diameter and a second plurality of particles, such as particle 42, having a second average diameter which is smaller than the first average diameter. The second average diameter in this embodiment, but not all, may be less than 10% of the first average diameter. The plurality of particles is in a brazing cable (or a wear-resistant coating formed using the brazing cable). The temporary binder and the wear-resistant coating binder are omitted for the sake of clarity. The inclusion of the second plurality of particles may result in better closure of the interstices. In one example, the plurality of round particles have an average diameter of 0.333 mm, the first plurality of particles (main interstitial particles) have an average diameter of 0.098 mm and the second plurality of particles (secondary interstitial particles) have a mean diameter of 0.008 mm. The other plurality of particles may comprise a third plurality of particles (tertiary interstitial particles) which have an average diameter which is smaller than the second average diameter, i.e. 0.001 mm. The other plurality of particles may be constructed of different materials such as diamond, tungsten carbide, tungsten, alumina, silicon carbide and silicon nitride or generally any suitable material. Their size and distribution can be chosen to maximize compaction density and wear behavior when deposited in consumable replenishment. In this embodiment, it is tungsten carbide. In Figs. 7 to 9, the plurality of round particles have a compact arrangement. Since the particles are round, they can adopt a compact arrangement that can be denser than other compact arrangements. Therefore, the number of elements per unit volume may be greater than for brazing cables and wear-resistant coatings having particles that are not in a compact arrangement. Increasing the number of elements per unit volume generally improves the wear resistance of the coating. Compact compaction can enhance the capillary action that displaces the melt brazing material through the plurality of round particles during bonding wherein the solder material infiltrates the interstices between the plurality of round particles. Therefore, the compact package can provide a relatively high structural integrity by a relatively better assembly of the plurality of round particles and largely avoid defects that may be encountered in the brazed material systems, caused by the distances between particles that are too important. Perfect compact arrangements can be obtained - generally a face-centered cubic arrangement, but in some embodiments, a compact hexagonal arrangement - when the plurality of round particles are identical perfect spheres. The compact arrangement of the plurality of round particles generally, but not necessarily, is flawed because the plurality of round particles generally move away from the perfect spheres and have different sizes. Nevertheless, the advantages provided by a defective compact arrangement of the plurality of round particles may approach those of a perfect compact arrangement.

In the embodiment of Figures 1 and 2, for example, the volume fraction of the plurality of round particles is at least 0.05 and not more than 0.85. The wear-resistant member of each of the plurality of round particles may have an ISO 6106 mesh size of at least 18 and not more than 120. In another embodiment (otherwise identical to that of FIGS. 2, for example), the wear-resistant member of each of the plurality of round particles may have an ISO 6106 mesh size of at least 18 and not more than 80. ISO stands for the International Organization for Standardization and the documents describing the 6106 standard are available to the public. FIG. 10 shows a flowchart for a method 100 for making the brazing cable 10. At a step 102 of the method, a mixture is formed, the mixture comprising the plurality of round particles 24, the wear-resistant coating binder. which, in the present embodiment, is in the form of a powder, and the temporary binder 16 which binds the mixture. Each of the plurality of round particles 24 comprises a rounded outer layer 28 encapsulating a wear resistant member 26. The method 100 includes the step 104 of extending the mixture. The wear-resistant coating binder may take the form of, for example, a powder comprising at least one of nickel, tungsten carbide, chromium and a fluxing agent. The fluxing agents can be self-fluxing and / or chemical fluxing agents. Examples of self-fluxing agents include silicon and boron, whereas chemical fluxing materials may be borate-based. In this embodiment, however, a fluxing agent and a deoxidant in the form of 2% silicomanganese carbon (ELKEM CHEMICALS or CHEMALLOY) are added to the mixture. In order to form the mixture, the plurality of round particles, the wear-resistant coating binder, the temporary binder and the other particles, as used including the other plurality of particles, may be mixed in a blender. industrial, fall into a free fall mixer or generally mixed using any suitable mixing process. Differences in density and shape may favor the segregation of the components of the mixture during cable manufacture. The use of a temporary binder can improve segregation. Once mixed, the mixture usually has a uniform distribution of its components. The mixture comprising the temporary binder can then be configured as a cable without significant segregation. Examples of temporary binders include, but are not limited to, mineral oil, polyethylene glycol, resin, an example of which includes, but is not limited to, RESINOXTM manufactured by OXYCHEM ™, and methyl cellulose based materials. In addition to eliminating the effects of segregation, the use of some temporary binders allows one to construct a cable form using material injection molding or extrusion. The mixture can be removed from the industrial blade mixer and then compressed in a uniaxial cold press to produce a cylinder 110 of the mixture, Figure 11. A bore may be formed in the cylinder, for example, by a drilling process or by squeezing mixing around a rod in the uniaxial cold press, which is then removed from the cylinder. Generally, the cylinder and the bore may be formed using any suitable technique. Fig. 12 shows an example of an extrusion apparatus 120 that can be used to form the brazing cable 10. A housing 122 of the apparatus 120 defines a cavity 124 in which the mixing cylinder 110 is disposed. The apparatus extrudes the mixture through an opening 132 of a die 130. The housing has a line port 134 for entering the line as a nickel wire 128 into the cavity. The line goes through the central bore of the mixture. Line 128 may be provided from a line coil (not shown). The extruded mixture, which is elongated by the extrusion, closes around the line, fixing the mixture to the line. The line is, in this embodiment, embedded in the mixture. In alternative embodiments, the mixture can not be attached to the line. The cable thus formed can then be wound on a reel or drum 126.

The rounded outer layers of the plurality of round particles can prevent contact of wear resistant materials with the die. Since the rounded outer layer is generally softer than the wear-resistant materials, wear on the die caused by contact of the hard-wearing materials with the die can be reduced. Alternative methods for extending the mixture to form a cable include rolling the mixture. Generally, any suitable method can be used. Figure 13 shows a micrograph of a wear resistant surface that can be formed using the cable. Making the plurality of round particles An exemplary method for making examples of the plurality of round particles is now described. Generally, any process for producing round particles can be used. A mixture of tungsten carbide powder having a Fisher 1 μm fine grain size and 1.2 μm Fisher finest grain size cobalt powder were mixed in 50/50 by weight. Alternatively or in addition to cobalt, any suitable metal powder may be used, for example a powder comprising at least one of nickel, copper and their alloys. 40/50 MBS955 Si2 diamonds in the mixture of tungsten carbide powder and cobalt powder were dropped with a binder in the form of methyl cellulose while controlled amounts of water were simultaneously sprayed on this last. Each diamond is covered to form the plurality of round particles in the green state. The plurality of round particles in the green state can then be heated in a Borel furnace in a hydrogen protective atmosphere. The plurality of green round particles may be heated from room temperature to above 500 ° C for approximately one hour. The plurality of round particles is maintained at 500 ° C for about 30 minutes. The temperature is then raised to 850 ° C for 180 minutes. The plurality of sintered round particles is allowed to cool. Applications Brazing cable 10 can be used to form a wear resistant coating on any suitable substrate. Some suggested applications are described now, however, it should be noted that there are many applications of wear-resistant coating. Stabilizers are used in the exploration and production of oil and gas. Their function is to provide drill stability and maintain dimensional control of the hole. The large sections of the stabilizer are in direct contact with the walls of the steel hole or box. Through rotation of the drill string and progressive drilling, the guards and the reloads are prone to wear, which can ultimately result in repair, end of life or dimensionally dimensional diameters. unacceptable. The stabilizer having a wear-resistant coating described herein, applied to it, can reduce or eliminate these problems. The twist and bicone rotary drills are made with protrusions or "teeth" that are machined from a parent steel. A drill with a wear-resistant coating described herein applied to it may have an increased life and exhibit reduced "tooth" wear, which can increase drilling performance and productivity. During the mechanical excavation and removal of the rocks, the main wear can be observed on the excavator's teeth and buckets. The excavator's teeth and buckets having a wear-resistant coating described herein applied thereto, can have an extended service life and hence replacement costs can be reduced. The outer diameter of a polycrystalline diamond drill is subject to sliding wear. A polycrystalline drill bit having a wear-resistant coating described here applied thereto may have an increased service life. During the life of a polycrystalline diamond drill, the body and drill blades that support the cutting structure may be subject to wear-limiting wear. The bodies and blades having a wear-resistant coating described herein applied to them can reduce erosive wear, which can increase tool life and reduce costs. Peaks are used during the mechanical excavation of the rock and the surface coating of road surfaces. A spike is generally made in two parts: the body and the insert. The body is conventionally steel and the insert is commonly tungsten carbide. In some circumstances, inserts containing diamond are used. The life of the body is usually limited by excessive wear or "wash".

A body having a wear-resistant coating as described herein and in close proximity to the insert may have an extended service life, and reduce the time required to replace worn out peaks. Mill teeth can be used in a variety of applications including mechanical oil extraction from oil-bearing sand. The grinder teeth can be positioned around a rotating drum and mechanically interact with rock, sand and oil. Wear can be important. Crusher teeth having a wear-resistant coating as described herein applied thereto, may have an extended service life.

In the context of oil and gas drilling, a mud-driven motor drives the rotation of the drill and the torque. The motor can contain both radial and axial bearings that are in sliding contact with opposite bearings or rolling elements. A bearing having a wear-resistant coating as described herein applied to it can significantly increase its service life, reduce bearing length and provide the capability for more bearing assemblies that favor higher drill weights and better drilling productivity for oil and gas. Now that the embodiments have been described, it should be noted that some embodiments may have some of the following advantages: A brazing cable may be suitable for forming a wear resistant coating on a substrate. Wear resistant elements have a relatively low density. Therefore, in the prior art, the wear-resistant elements may be poorly distributed in the wear-resistant coating and may be in close proximity to one another, or even touch one another, which may weaken the structure. since solder infiltration can be reduced. Fine coatings on a super hard material may not completely overcome these differences in density or prevent part-to-part contact. Encapsulation of the wear-resistant elements can improve these problems. - The round nature of the encapsulant and / or the careful selection of the sizes and shapes of the particles occupying the interstices promotes high compaction and further optimizes wear resistance. - The structure of the encapsulant can be an open or closed structure. Open semipore topography can provide a large surface area and significant capillary forces for reaction and infiltration. During cooling and solidification of the brazing material, the encapsulated wear-resistant elements can be placed under compression by the encapsulant, providing improved retention and improved wear properties. - Liquid metal infiltration of the encapsulant during the brazing process and subsequent solidification can provide a mechanically enhanced compressional tension that maintains and connects the wear resistant members. The super hard encapsulated elements may not benefit from this advantage. The wear resistant elements discussed herein may have considerably increased hardness and wear resistance compared to tungsten carbide metal dies formed by conventional hardfacing materials. - The wear-resistant elements can be metallurgically connected to the wear-resistant binder by means of the intermediate coating 30.

This can improve the attachment of the wear resistant elements and the performance and service life of the wear resistant coating. Variations and / or modifications may be made to the described embodiments without departing from the spirit and scope of the invention. For example, while the substrate described above is steel, it should be noted that embodiments may be used on other substrate materials, for example another metal such as aluminum, a carbide of tungsten or generally any suitable substrate material. The present embodiments must, therefore, be considered in all respects as illustrative and not restrictive.

The prior art described herein, if it exists, should not be taken as an admission that the prior art is part of the general common knowledge in any jurisdiction. In the following claims and in the preceding description of the invention, unless otherwise indicated by language expression or necessary implication, the term "understand" or variants such as "comprises" or "comprising" is used in a inclusive meaning that must specify the presence of established characteristics but does not exclude the presence or addition of other features in different embodiments of the invention.

Claims (18)

REVENDICATIONS1. Brazing cable for forming a wear-resistant coating on a substrate by a brazing process, the brazing cable comprising a mixture comprising a plurality of round particles, a wear-resistant coating binder to bind the plurality of round particles in the wear-resistant coating when formed, and a temporary binder which binds the blend, each of the plurality of round particles comprising a rounded outer layer encapsulating a wear-resistant member. 2. Brazing cable according to claim 1, comprising a line along which the mixture is placed. Brazing cable according to claim 2, wherein the mixture is fixed on the line. 20 4. Brazing cable according to one of claims 2 and 3, wherein the line comprises at least one of iron and nickel. 25 The brazing cable of any one of claims 2 to 4, wherein the line comprises one of a wire and a braided cord. The brazing cable of any one of claims 1 to 5, wherein the wear resistant member of each of the plurality of round particles has a metallurgically bonded coating thereto, the coating being Metallurgically connected to the wear-resistant coating binder. A method of making a brazing cable to form a wear resistant coating on a substrate by a brazing process, the method comprising the steps of: forming a mixture comprising a plurality of round particles, a coating binder wear-resistant to bind the plurality of round particles in the wear-resistant coating, when formed, and a temporary binder which binds the mixture, wherein each of the plurality of round particles comprises an outer layer rounded encapsulating a wear resistant element; and lengthen the mixture. 15 The method of claim 7, wherein the step of extending the mixture comprises the step of arranging the mixture along a line. The method of claim 8, wherein the step of extending the mixture comprises the step of securing the mixture along the line. The method of claim 9, wherein the mixture is secured along the line by simultaneously extruding the mixture through a die and stretching the line in the die. 30 The method of claim 10, wherein the step of extending the mixture comprises the step of rolling the mixture. 20 25 The method of any one of claims 7 to 11, wherein the step of extending the mixture comprises the step of configuring the mixture into a cable form. A method according to any one of claims 7 to 12, wherein the wear resistant member of each of the plurality of round particles has a metallurgically bonded coating thereto, the coating being connectable by metallurgical material with wear-resistant coating binder. 14. A wear-resistant coating on a substrate, the wear-resistant coating comprising: a composite material comprising a plurality of round particles connected together by a wear-resistant coating binder, wherein each of the plurality of round particle comprises a rounded outer layer encapsulating a wear-resistant member, the wear-resistant coating binder penetrates the rounded outer layer and is metallurgically bonded to a metallurgically bonded coating to the wear resistant member; the wear of each of the plurality of particles, wherein the wear-resistant coating binder is metallurgically bonded to at least one of an inner surface and an outer surface of the rounded outer layer of each of the plurality of round particles. The wear resistant coating of claim 14, wherein the wear resistant coating binder comprises a metal bonding material. The wear-resistant coating of one of claims 14 and 15, wherein the metal bonding material comprises a monolithic matrix of the metal bonding material. 17. A method of forming a wear-resistant coating on a substrate, the method comprising the steps of: heating a brazing cable according to any of claims 1 to 6 to form a solder binder brazing cable; wear-resistant coating melted; and allowing the molten brazing cable to flow over a surface of the substrate. 18. The method of claim 17, wherein the wear-resistant coating so formed is according to any one of claims 14 to 16.