WO2025165245A1

WO2025165245A1 - Systems and methods for limiting core movement during firing of ceramic molds

Info

Publication number: WO2025165245A1
Application number: PCT/PL2024/050004
Authority: WO
Inventors: Ethan Conrad Schaeffer; Canan Uslu Hardwicke; Jared Michael Iverson; Suman Das; Nicholas A. HOGBERG
Original assignee: GE Infrastructure Technology LLC
Current assignee: GE Vernova Infrastructure Technology LLC
Priority date: 2024-01-30
Filing date: 2024-01-30
Publication date: 2025-08-07
Anticipated expiration: 2026-07-30

Abstract

A fixturing system includes a fixturing plate including at least one aperture defined therein, the fixturing plate sized to be inserted within the cavity. The fixturing plate further including an outer boundary that is at least partially shaped complementary to an inner surface of a shell. The fixturing system includes at least one of a fixturing rod sized to be inserted through the aperture of the fixturing plate, such that the at least one the fixturing rod extends into the cavity between the fixturing plate and the core to facilitate securing a relative position of the core during a firing process.

Description

SYSTEMS AND METHODS FOR LIMITING CORE MOVEMENT DURING FIRING OF CERAMIC MOLDS

FIELD

[0001] The field of the disclosure relates generally to ceramic components that include a core and more particularly, to systems and methods that limit core movement during firing of shell and core ceramic components.

BACKGROUND

[0002] Turbine buckets or blades, such as those used with gas turbine engines, aircraft engines, and/or steam turbines, for example, may be formed using a mold and casting process. Conventionally, molds are formed of ceramic materials and include an outer ceramic shell having an internal surface defining a cavity and one or more ceramic cores positioned within the cavity that form interior cooling passageways within the cast bucket. Ceramic molds may be formed using a lost-wax casting process, wherein cores are first formed by ceramic injection molding into a machine core die. Molded cores may then be fired to high temperatures in order to strengthen the core, and then subsequently, the fired core is placed in another machined wax die for forming the shell surrounding the core. More recently, manufacturing processes may form the core and shell ceramic component using a 3-D printing process and the core and the shell may be fired at the same time. Movement or deflection of the core within the cavity during firing may result in distortion of the cooling passageways, may cause narrowing between an inner wall of the shell and the core, and/or in some cases, may cause core kissout, a condition when the core contacts an inner surface of the shell.

[0003] In known conventional casting methods multiple firing fixtures, such as platinum pins may be used to secure the position of the core within the shell. The fixtures used to hold the core in place may be temporarily inserted through openings defined in the shell of the ceramic mold. After firing, the fixtures are removed, and the openings formed in the shell must be repaired and/or filled, thus increasing the time and cost to form molds that include cores.

[0004] Accordingly, a need exists for systems and methods of limiting core movement during firing of ceramic molds that overcome the limitations described above. SUMMARY

[0005] In one aspect, a fixturing system for use with a mold used for fabricating a component is provided. The fixturing system includes a fixturing plate including at least one aperture defined therein. The fixturing plate is sized to be inserted within a cavity defined within a shell of the mold. The fixturing plate further having an outer boundary that is shaped at least partially complementary to an inner surface of the shell. The fixturing system includes at least one of a fixturing rod sized to be inserted through the aperture of the fixturing plate such that the at least one fixturing rod extends into the cavity and between the fixturing plate and a core of the mold to facilitate securing a relative position of the core during a firing process.

[0006] In another aspect, a mold system for use in fabricating a component is provided. The mold includes a shell defining a cavity and a core positioned within the cavity; and a fixturing system for use in securing a position of the core relative to the shell during a firing process, the fixturing system includes a fixturing plate comprising at least one aperture defined therein. The fixturing plate is sized to be inserted within the shell cavity and including an outer boundary that is shaped at least partially complementary to an inner surface of the shell. The mold system includes at least one fixturing rod sized to be inserted through the aperture of the fixturing plate such that the at least one fixturing rod extends into the cavity and between the fixturing plate and the core to facilitate securing a relative position of the core during a firing process.

[0007] In yet another aspect, a method of forming a mold for forming a cast component is provided. The method includes positioning a fixturing plate within a cavity defined by a shell of a mold used to form the component. The fixturing plate includes at least one aperture defined therein. The method includes inserting a securing member at least partially through the aperture such that the securing member extends between the fixturing plate and a core positioned within the shell, and such that the securing member contacts the core.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] These and other features, aspects, and advantages of the present disclosure will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein: [0009] FIG. 1 is a side view of an exemplary mold that may be used with a core fixturing system to form a component, such as a component shown in FIG. 11, for example.

[0010] FIG. 2 is a top view of the mold and core fixturing system shown in FIG. 1.

[0011] FIG. 3 is a bottom view of the mold and core fixturing system shown in FIGS. 1 and 2.

[0012] FIG. 4 is a cross-sectional view of the mold shown in FIG. 1 along line A-A, showing a core positioned within a cavity, and the core fixturing system including a fixturing plate, at least one fixturing rod, and at least one fixturing insert.

[0013] FIG. 5 is a cross-sectional view of the mold shown in FIG. 1 along line B-B.

[0014] FIG. 6 is a top view of the fixturing plate.

[0015] FIG. 7 is a perspective view of a fixturing insert.

[0016] FIG. 8 is a cross-sectional view of yet another exemplary mold that may be used with the core fixturing system shown in FIGS. 1 and 2, taken along line C-C.

[0017] FIG. 9 is a cross-sectional view of a further exemplary mold that may be used with the core fixturing system shown in FIGS. 1 and 2, taken along line C-C.

[0018] FIG. 10 is a perspective transparent view of a cast metal component formed using the mold and core fixturing system shown in FIGS. 1 and 2, taken along line C-C.

[0019] FIG. 11 is a process flow diagram of an exemplary method for fixturing a core for use with the core fixturing system FIGS. 1-3 for example.

[0020] Unless otherwise indicated, the drawings provided herein are meant to illustrate features of embodiments of the disclosure. These features are believed to be applicable in a wide variety of systems comprising one or more embodiments of the disclosure. As such, the drawings are not meant to include all conventional features known by those of ordinary skill in the art to be required for the practice of the embodiments disclosed herein.

DETAILED DESCRIPTION

[0021] In the following specification and the claims, reference will be made to a number of terms, which shall be defined to have the following meanings. The singular forms “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise. “Optional” or “optionally” means that the subsequently described event or circumstance may or may not occur, and that the description includes instances where the event occurs and instances where it does not. Furthermore, references to “one embodiment” are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. Moreover, unless explicitly stated to the contrary, embodiments “including” or “having” an element or a plurality of elements having a particular property may include additional such elements not having that property.

[0022] As used herein, the term “real-time” refers to either the time of occurrence of the associated events, the time of measurement and collection of predetermined data, the time to process the data, or the time of a system response to the events and the environment. In the embodiments described herein, these activities and events occur substantially instantaneously.

[0023] In the exemplary embodiments described herein, a core fixturing system and methods for manufacturing a mold is provided. The mold may be used to produce a cast component, such as a turbine bucket, which includes at least one interior cooling passageway formed therein. In the exemplary embodiment, the mold includes a shell that at least partially defines a cavity therein. The mold also includes one or more cores positioned within the cavity defined by the shell. The mold, including the shell and the core, may be used to cast an object formed with a hollow chamber, such as a cooling cavity or passageway, which extends through or partially into the cast component. In particular, the mold cavity defines the shape of the cast component, for example, in the exemplary embodiment, the mold cavity is the space defined between an inner surface of the shell and an outer surface of the core. The inner surface of the shell forms an outer surface of the cast turbine bucket and the outer surface of the core forms an inner cooling chamber of the cast turbine bucket.

[0024] In some embodiments described herein, the buckets may be formed using a casting process wherein molten metal is cast into the ceramic mold. In particular, molten metal is poured into the cavity defined by an internal surface of the shell, encapsulating an external surface of the ceramic core. After the molten metal is cooled and solidifies, the shell and the core are removed resulting in a desired metallic turbine blade including an internal cooling chamber formed by the core.

[0025] The mold may be printed, or formed using any suitable manufacturing technique, using a ceramic material that is fired via a kiln or any other suitable oven, for example. In the exemplary embodiments, cores are manufactured by printing the core and the shell at the same time or substantially the same time using any suitable 3D printing process, for example and without limitation, sunk-type digital light processing, stereolithography, and/or printing layers of the shell and the core and/or by injection molding of ceramic slurries into a machined die.

[0026] In some embodiments, the ceramic material may include ceramic matrix composites, carbide, oxides, nitrides, one or more of the following compounds, SiO2, A12O3, BN, BC, Si3N4, HfO2, ZrO2, SiC, silicates, phosphates, etc., and/or ceramic fibers. Alternatively, the ceramic mold may be formed of any suitable material, using any suitable manufacturing technique that enables the systems and methods to function as described herein.

[0027] In exemplary embodiments described herein, the method of manufacturing the mold, including the shell and the core, prevents creep or deflection of the core within the cavity during firing and/or eliminates post cast manufacturing processes, such as machining and/or drilling to repair defects. Conventionally, defects may be created by extending shell core fixturing features through the shell of the mold to facilitate holding the core in position during firing. Additionally, defects may be caused by misalignment or movement of the core during firing. The exemplary embodiments described herein eliminate one or more mold and/or post cast manufacturing processes by maintaining the position and alignment of the core using core fixturing that does not extend through the shell and/or disrupt the inner surface of the shell.

[0028] In the embodiments described herein, a core fixturing system is provided that enables a mold including the shell and the core by maintaining the alignment and/or position of the core within the cavity to facilitate preventing or reducing narrowing in a space between the core and the shell and/or preventing kissout during high temperature firing of the mold. As used herein, the term kissout may refer to contact between the core and the shell during the firing process, such that a cast part, formed from a mold having kissout, will undesirably be formed with at least one opening and/or at least one thinned wall. In the exemplary embodiment, the core fixturing system includes a fixturing plate and at least one fixturing rod, and/or at least one fixturing insert. In some embodiments, the fixturing rods extend downwardly from a tip portion of the mold towards a tail portion of the mold. The fixturing inserts extend upwardly from the tail portion of the mold towards the tip portion of the mold. [0029] In embodiments described herein, the fixturing system is modular and thus enables users to selectively utilize any suitable combination of rods or inserts, simultaneously (e.g., a combination a rods and inserts) and/or separately or independently (e.g., using only rods or using only inserts) necessary to support the core. The rods and inserts also may be variably positioned at various depths to support the core at various locations along a length of the core. In addition, the shape and/or size of the rods and/or the inserts may also be selectively adjusted to support the core. For example, the inserts may include one or more surfaces that are shaped complimentary to a surface of the core, such that when the insert supports the core, the insert contacts the core over a contact surface area. The diameter of the rods may be variably increased or decreased to enable the contact area between the core and rods to be varied. The apertures of the fixturing insert plate may also be variably sized and/or spaced, e.g., spacing between apertures, size of aperture, insertion direction etc., to enable the placement and insertion directions of rods used to support the core to be customized.

[0030] FIGS. 1-5 illustrate an exemplary core fixturing system 100 that may be used for forming a mold 110. The mold 110 includes a shell 112 and at least one core 114 positioned within a cavity 116 that is defined, at least partially, by an inner surface 118 of the shell 112. The core 114 is positioned within the cavity 116 such that the cavity 116 extends between an outer surface 120 of the core 114 and the inner surface 118 of the shell 112, as best seen in Fig.4, which illustrates a cross-sectional view of the mold 110 shown in Fig. 1. The core 114 may be separated from the shell 112 by a distance dl 14. The shell 112 has a height Hl 12 that extends between a lower end 122 and an upper end 124 that is generally opposite along a vertical direction Z. The shell 112 includes a tip portion 130, a body portion 132 (e.g., an airfoil section of a blade), a tail portion 134 (e.g., a shank), and a base 136 (visible in Fig. 3). In the exemplary embodiment, the mold 110 may be used during a casting process to form a turbine blade 300 (shown and described with respect to FIG. 10), having one or more cooling passageways formed by the core 114 of the mold 110, as described below.

[0031] The core 114 has a height Hl 14 extending between a lower end 140 and an upper end 144 generally along the vertical direction Z. In some embodiments, the core 114 may be supported by the base 136 and extend from the lower end of the shell 112, in the vertical direction Z, through the tail portion 134. In some embodiments, the core 114 may extend, from the base 136, through the body portion 132 and/or through the tip portion 130. The core 114 may have any suitable height as required by the component to be formed. In some embodiments, the core 114 may be centrally located within the cavity 116, such that the core 114 is substantially equidistant between opposing sides of the inner shell surface 118 defining the cavity 116. In other embodiments, the core 114 may be positioned in any other suitable location within the cavity 116. The core 114 may have any suitable shape as desired and/or selected by an operator to achieve a resultant cast object. For example, the core 114 may include at least one arcuate surface, e.g., one or more concave surfaces and/or one or more convex surfaces. See Fig. 5. In some embodiments, the core 114 may be a solid component. Alternatively, in some embodiments, the core 114 may be hollow and the core 114 may have a wall thickness (not shown). In some embodiments, the core 114 may include one or more core channels 156, described below.

[0032] The core fixturing system 100 may be used to maintain the position or alignment of the core 114 within the cavity 116, particularly during firing of the mold 110. In the exemplary embodiment, the core fixturing system 100 includes a fixturing plate 150, and one or more fixturing rods 152 and one or more fixturing inserts 154. In embodiments described herein, the core fixturing system 100 is modular, such that any suitable number of rods 152 and/or inserts 154, may be used, e.g., a combination of rods 152 and inserts 154, and/or used independently, e.g., only rods 152 or only inserts 154.

[0033] In the illustrated embodiments, the mold 110 may include one upper opening 160 (shown in FIG. 2). The mold 110 may include one or more slots 162 formed in the base 136 of the mold 110. For example, in the exemplary embodiment, the mold 110 may include a first and second slot 163 and 164 (shown in FIG. 3), oriented substantially parallel to each other. The slots 162 may be elongated and have a length LI 62 and a width W162. In other embodiments, the mold 110 may include any suitable number of upper openings 160 and/or any suitable number of slots 162. The fixturing plate 150 may be positioned within the cavity 116 such that it is adjacent to, or within, the tip portion 130. The fixturing plate 150 may be shaped complimentary to the inner surface 118 of the tip portion 130. In other embodiments, the fixturing plate 150 may have any shape that enables the system 100 to function as described herein. In some embodiments, the fixturing plate 150 may extend across the upper opening 160.

[0034] The fixturing plate 150 may be selectively coupled to the shell 112 by resting the fixturing plate 150 against a shelf 146, visible in FIG. 2, formed integrally with the shell 112 and extending therefrom towards the cavity 116. In some embodiments described herein, the fixturing plate 150 includes an outer boundary 168 that is shaped complimentary to the inner surface 118 of the tip portion 130. When the plate 150 is positioned within the cavity 116, the outer boundary 168 of the fixturing plate 150 may be in contact with the inner surface 118 of the tip portion 130, e.g., when the lower surface 172 of the fixturing plate 150 is resting on the shelf 146.

[0035] In the exemplary embodiment, the fixturing plate 150 is generally planar and has a thickness tl50 of between 0-10 mm , measured between a substantially planar upper surface 170 and a substantially planar lower surface 172 that is oriented substantially parallel to the upper surface 170 as best seen in FIG. 4. In the exemplary embodiment, the fixturing plate 150 includes one or more apertures 166, as will be described in more detail below.

[0036] In further reference to FIG. 9, the rods 152 and the inserts 154 may be used simultaneously during the same firing process, to secure the position and/or the alignment of the core 114 within the cavity 116 and relative to the shell 112. In some embodiments, the inserts 154 and the rods 152 extend along, or are each substantially parallel to, the vertical direction Z. In alternative embodiments, the rods 152 and/or the inserts 154 may extend in any direction and/or for any length, which enables the systems and methods to function as described herein. In some embodiments, the rods 152 may be oriented at an angle relative to the axial direction Z.

[0037] In some embodiments, the fixturing inserts 154 may be formed of a ceramic material. In some embodiments, the fixturing insert 154 may be formed of the same material as the shell 112 and/or the core 114. In some embodiments, the fixturing inserts 154 may be printed during printing of the core 114 and shell 112. In some embodiments, the fixturing inserts 154 may be formed separately from the core 114 and shell 112 and then the fixturing inserts 154 may be inserted, through one of the slots 162, 163, into the cavity 116. Alternatively, the fixturing insert 154 may be formed during forming of the shell 112 and core 114, e.g., for mold 110 configurations having complicated geometries that do not allow the fixturing insert 154 to be inserted into the cavity 116 without interfering with the core 114. In reference to FIG. 7, in some embodiments, the fixturing insert 154 includes a body portion 176 and a base portion 178. The base portion 178 may have a width W178 that is greater than a width W176 of the body portion 176. The fixturing insert 154 may have a height H154. The height H154 of the fixturing insert 154 may be substantially the same as the height Hl 14 of the core 114. In some embodiments, the height H154 of the fixturing insert 154 may be less than the height Hl 14 of the core 114. The fixturing insert 154 may have a thickness tl54. The thickness tl54 is selected such that the fixturing insert 154 may be disposed between the core 114 and the shell 112. The thickness tl54 may be relatively constant along the height Hl 14. The thickness tl54 may vary along the height Hl 14 and/or the width W176 as selected such that the fixturing insert 154 fits between the core 114 and shell 112. The fixturing insert 154 may, or may not, contact the inner surface 118 of the shell 112 and/or contact the outer surface 120 of the core 114.

[0038] In some embodiments, fixturing inserts 154 may have other configurations and/or dimensions. In some alternative embodiments, the fixturing inserts 154 may be formed of ceramic sheets. In some embodiments, the ceramic sheets may be flexible and may be inserted through the slots 162, 163. In other alternative embodiments, the fixturing inserts may be embodied as a plurality of individual spheres, e.g., ceramic spheres, which may be inserted through the slots 162, 163, or in some embodiments, through the upper opening 160. The spheres may have a diameter between .1-10 mm. The spheres may have any suitable dimension and/or number which may be used to retain the core position and alignment, e.g., to fill the space between core 114 and the shell 112.

[0039] In some embodiments, the rods 152 extend downwardly from the tip portion 130 towards the tail portion 134 of the mold 110. In some embodiments, the rods 152 may not extend fully to the tail portion 134. The rods 152 may extend, from the tip portion 130 to the core 114 such that at least a portion of the fixturing rod 152 contacts the core 114. In some embodiments, the rods 152 extend downwardly from the tip portion 130 and contact the core outer surface 120 to retain the core 114 in a fixed or semi-fixed position. The core 114 includes one or more core channels 156 formed in the core 114 having a complementary shape to the rods 152, such that the rods 152 may be inserted into the core 114. For example, the one or more core channels 156 may have a diameter dl56 that is similar or slightly larger than a diameter of the rods 152. In some embodiments, the fixturing rod 152 contacts, but does not penetrate the core 114 outer surface 120. In some embodiments, the rods 152 may penetrate the core 114 to a depth of approximately 10mm. In some embodiments, the rods 152 may penetrate the core 114 all the way through the core 114, to the base 136. In some embodiments, the rods 152 may be inserted to any suitable penetration depth. In some embodiments, the rods 152 may include a tapered and/or a pointed end. In some embodiments, the rods 152 have a flattened end. The tapered and/or a flattened end of the rods 152 may facilitate insertion of rods 152 into the core channels 156. In some embodiments, the core channel 156 may be shaped complementary to the rods 152, having a tapered surface to engage with a tapered surface of the rods 152. [0040] In further reference to FIG. 6, in the exemplary embodiment, the rods 152 may be secured in place via the fixturing plate 150. The rods 152 may extend through the apertures 166 defined in the fixturing plate 150. In the exemplary embodiment, the rods 152 extend between the fixturing plate 150 and the core 114 to an insertion depth dl52. In some embodiments, fixturing plate 150 may include an array of apertures 166, arranged in a grid-like pattern wherein adjacent apertures 166 are spaced substantially equidistant apart. In other embodiments, the apertures 166 may be arranged in a concentric circular pattern. Alternatively, the apertures may be arranged in any orientation and/or pattern enabling selective placement of the fixturing rods 152.

[0041] In the exemplary embodiment, the apertures 166 are each circular and each has a diameter D166. Each aperture 166 extends through the thickness tl50 of the fixturing plate 150, such that each aperture 166 defined by a wall 174 that is generally cylindrical in shape. The wall 174 defining the apertures 166 may be shaped complementary to the outer shape of the rods 152. In the illustrated embodiment, the rods 152 are cylindrical and may be inserted within the cylindrically shaped apertures 166. In alternative embodiments, the rods 152 may be rectangular and the apertures 166 may be shaped with a complementary rectangular shape sized to enable the rectangular- shaped rods to extend through the rectangular- shaped apertures 166. In some embodiments, at least one aperture 166 may be cylindrical and at least one of the apertures 166 may be rectangular. The apertures 166 may have any suitable shape that enables the systems and methods to function as described herein.

[0042] In some embodiments, when the fixturing plate 150 is positioned within the shell 112, the apertures 166 extend through the fixturing plate 150 along the vertical direction Z. In some embodiments, when the fixturing plate 150 is positioned within the shell 112, at least one of the apertures 166 is aligned such that it extends through the fixturing plate 150 at an angle relative to the vertical direction Z, such that rods 152 inserted through that aperture 166 extend obliquely through the cavity 116 relative to the vertical direction Z.

[0043] Because the plurality of apertures 166 are spaced across the fixturing plate 150, operators have the flexibility to vary the number of rods 152, the placement of the rods 152, and/or the shape of the rods 152, based on the particular shape and/or configuration of the core 114. The apertures 166 may be arranged in any suitable pattern and/or configuration that enables the fixturing system 100 to function as described herein. As such, in the embodiments described herein, the fixturing system 100 is modular such that a user may use any number of suitable rods 152 necessary to facilitate preventing or limiting deflection of the core 114 during firing of the mold 110.

[0044] The one or more inserts 154 extend upwardly from the tail portion 134 toward the tip portion 130 of the mold 110. In some embodiments, the inserts 154 extend only partially from the tail portion 134 towards the tip portion 130. In other embodiments, the inserts 154 extend fully from the base 136 of the mold 110 upwardly towards the upper end 144 of the core 114.

[0045] The inserts 154 have a first fixturing surface 180 that faces the core 114 and a second fixturing surface 182 that faces the shell 112. The first and second surfaces 180 and 182, respectively, may be opposing surfaces. The first surface 180 may be shaped complimentary to the outer surface 120 of the core 114. The first fixturing surface 180 may contact the core 114 over a contacting surface area. The first fixturing surface 180 may extend along the full height Hl 14 of the core 114. In some embodiments, the total first fixturing surface area 180, based on the totality of all of the inserts 154, may extend across a majority of the core 114 outer surface 120. The core contacting surface, i.e., the first fixturing surface, 180 is variably sized to support the core 114 in an upright position and/or to facilitate preventing the core 114 from deflecting, shifting, or moving, particularly during firing. The first fixturing surface 180 may prevent the core 114 from deflecting.

[0046] In some embodiments described herein, the mold 110 may be formed of a ceramic material during a printing process, for example, also referred to as an additive manufacturing process, and then subsequently, the formed mold 110 may be fired, e.g., in an oven or a kiln, for example, to cure and sinter the ceramic mold 110 into a hardened ceramic material. In the embodiments described herein, the shell 112 and the core 114 may be printed at the same time or substantially the same time using any suitable 3D printing process, for example and without limitation, sunk-type digital light processing, stereolithography, binder jet or extrusion processes, and/or printing layers of the shell 112 and the core 114. In some embodiments, for example, the shell 112 and the core 114 are printed separately or independently and are then assembled. In such embodiments, a ceramic printer may print the core 114 and later print the shell 112 around the exterior of the core 114. In some other embodiments, the printer may alternate between printing layers of the core 114 and layers of the shell 112. In some embodiments, the printed core 114 may be used in a wax process and the shell 112 may be created by a ceramic dipping process. In another embodiment, during core 114 and shell 112 printing, sections and/or layers of the shell may be printed and subsequently or iteratively, additional layers of the shell 114 may be built-up by a slurry dipping process. In further reference to FIG. 10, the turbine blade 300 may be formed of a metal or metal alloy. Molten metal may be poured into the cavity 116 defined by the inner surface 118 of the shell 112 and the outer surface 120 of the core 114. In such an embodiment, the outer surface 120 of the core 114 is spaced and remains a distance dl 14 from the inner surface 118 of the shell 112. The distance dl 14 may be any suitable distance that enables a suitable wall thickness of the turbine blade 300 to be formed. After cooling, the mold 110 or portions of the mold 110 may be removed from the hardened metal, resulting in the formed turbine blade 300 including a portion 332 and a portion 334. The turbine blade 300 may include a cooling chamber 314, formed by the core 114. The rods 152 may be used to form cooling passages 352.

[0047] In some embodiments, one or more of a ceramic shim, not shown, may be inserted through the upper opening 160. The ceramic shims may be positioned between the core and the shell to maintain a tip gap therebetween.

[0048] In some embodiments, the shell 112 may include a tip core positioned within the tip portion 130 and/or the body portion 132. In embodiments including a tip core, a shortened fixturing rod 152 may be used to hold the position of the tip core relative to the shell 112. In addition, one or more inserts 154 may be inserted through the upper opening 160, to be positioned between the tip core and the shell 112 to hold the position of the tip core.

[0049] While embodiments of systems and methods described herein relate to molds used for casting turbine buckets, the mold 110 and fixturing system 100 may be used to cast other items. For example, the systems and methods described herein may be used to manufacture molds for casting any objects having an outer surface and an inner cavity formed by the core 114 of the mold 110.

[0050] FIG. 11 is a process flow of an exemplary method 900 for forming a mold 110, for example, using the core fixturing system 100 shown in Figs. 1-10. The method 900 may include one or more process steps described below.

[0051] Method 900 may include forming, prior to firing, the mold 110 including the shell 112 and the core 114. Forming the mold 110 may include forming the shell 112 defining the cavity 116. Forming the mold 110 may also include forming the core 114. In some embodiments, the core 114 may be formed separately from the shell 112 and then subsequently the core 114 may be positioned within the cavity 116. In some embodiments, the core 114 may be formed within the cavity 116. Forming the mold 110 may include printing the mold 110, e.g., from ceramic material. The shell 112 and core 114 are printed at the same time, or substantially the same time, e.g., using any suitable 3D printing process, for example and without limitation, sunk-type digital light processing, stereolithography, binder jet, slurry extrusion, and/or printing layers of the shell 112 and the core 114.

[0052] Method 900 may further include additional steps for forming the mold 110 prior to firing, in order to facilitate maintaining the relative position of the core 114 within the cavity 116 during the firing process.

[0053] In some embodiments, method 900 may include forming the fixturing plate 150 for use with the core fixturing system 100. Forming the core fixturing plate 150 may include cutting or stamping the boundary of the core fixturing plate 150 in a shape complimentary to the inner surface 118 of the shell 112. Forming the fixturing plate 150 may include cutting, forming, or stamping out one or more apertures 166 through the plate 150.

[0054] Method 900 may include positioning 902 the core fixturing plate 150 within the cavity 116 defined by the inner surface 118 of the shell 112. Positioning 902 the core fixturing plate 150 may include resting the core fixturing plate 150 on the shelf 146.

[0055] Method 900 may include positioning 902 at least one rod 152 through at least one aperture 166 defined in the core fixturing plate 150. Positioning 902 the at least one rod 152 may include extending the fixturing rod 152 between the core fixturing plate 150 and the core 114. Positioning 902 the at least one rod 152 may include passing the fixturing rod 152 through the aperture 166 along the full length of the mold 110 until a distal end of the fixturing rod 152 comes into contact with the core 114. The fixturing rod 152 may contact the outer surface 120 of the core 114 such that the rod 152 is not inserted into the core 114. Method 900 may include positioning a plurality of rods 152 at various locations around the circumference of the core 114 and/or a various insertions depths such that a plurality of rods 152 may contact the core 114 at various locations along the height Hl 14 of the core 114.

[0056] Method 900 may include positioning 904 at least one insert 154 within cavity 116. Positioning 904 at least one fixturing insert may include extending the fixturing insert through one or both of the slots 162 defined in the base 136 of the mold 110. Positioning 904 the inserts 154 may include inserting the fixturing insert through the slot until at least a portion of the fixturing insert 154 comes into contact with an exterior surface of the core 114. Method 900 may include positioning a plurality of inserts 154 at various locations around the outer surface 120 of the core 114 and/or at various insertion depths such that a plurality of inserts 154 may be positioned into contact with the core 114 at various locations along the height Hl 14 of the core 114. Method 900 may include positioning one or more rods 152 and positioning one or more inserts 154 such that the rods 152 and inserts 154 overlap in the vertical direction. In some embodiments, method 900 may further include using only inserts 154 or using only using rods 152. Method 900 includes firing 906 the mold 110, wherein the core 114 is secured in place by at least one rod 152 and/or at least one insert 154.

[0057] Method 900 may include firing 908 the mold 110, with at least one of the fixturing plate 150, inserts 154 and/or rods 152 positioned to maintain the relative position of the core 114 within the shell 112. Method 900 includes, after firing 908, removing 910 the fixturing insert 154, removing 910 the rods 152 and/or removing 910 the core fixturing plate 150 from within the cavity 116. Removing 910 may include manually pulling the insert 154 or rods 152 to remove them from the cavity 116. In some embodiments, the inserts 154 may shrink, e.g., during firing, loosening the position of the inserts 154 within the cavity 116, such that the inserts 154 may be easily removed from the cavity 116.

[0058] In some embodiments, rods 152 are not removed before casting the turbine bucket, rather the rods 152 remain in place, e.g., disposed with the core channels 156, are used to form cooling passages, e.g., cooling passages 352 shown in Fig. 10, in the cast turbine bucket. In some embodiments, the fixturing plate 150 is also not removed before casting the bucket.

[0059] In some embodiments, method 900 does not include repairing the shell 112. For example, if the inserts 154 and the rods 152 do not extend through the shell 112, then the inserts and rods will not form openings in the shell 112 that need to be repaired after firing. In some embodiments, method 900 does not include repositioning the core 114 within the shell 112, as the core 114 is maintained in position using the core fixturing system 100.

[0060] Further aspects of the present disclosure are provided by the subject matter of the following clauses:

[0061] 1. A fixturing system for use with a mold used for fabricating a component, the fixturing system comprising: a fixturing plate including at least one aperture defined therein, the fixturing plate sized to be inserted within a cavity defined within a shell of the mold, the fixturing plate further having an outer boundary that is shaped at least partially complementary to an inner surface of the shell; and at least one of a fixturing rod sized to be inserted through the aperture of the fixturing plate such that the at least one fixturing rod extends into the cavity and between the fixturing plate and a core of the mold to facilitate securing a relative position of the core during a firing process.

[0062] 2. The system in accordance with any preceding clause, wherein the fixturing system further comprises: a fixturing insert that is sized to be positioned within the cavity between the core and the shell.

[0063] 3. The system in accordance with any preceding clause, wherein the fixturing insert has a height that is approximately the same as a height of the core.

[0064] 4. The system in accordance with any preceding clause, wherein the aperture of the fixturing plate is defined by an outer boundary that is sized and shaped substantially complementary to an outer surface of the fixturing rod.

[0065] 5. The system in accordance with any preceding clause, wherein the at least one fixturing insert includes an outer surface, wherein a portion of the outer surface is shaped substantially complimentary to a portion of an outer surface of the core.

[0066] 6. The system in accordance with any preceding clause, wherein the fixturing system further includes a first fixturing insert and a second fixturing insert that is positioned on an opposite side of the core from the first fixturing insert.

[0067] 7. The system in accordance with any preceding clause, wherein the fixturing plate includes at least a first aperture having a first diameter and a second aperture having a second diameter that is different from the first diameter.

[0068] 8. The system in accordance with any preceding clause, wherein the fixturing plate is defined by an outer boundary that is shaped substantially complementary to an inner surface of the cavity, wherein the fixturing plate is positioned on a shelf protruding from the shell.

[0069] 9. A mold system for use in fabricating a component, the mold system comprising: a mold for use in fabricating the component, the mold comprising a shell defining a cavity and a core positioned within the cavity; and a fixturing system for use in securing a position of the core relative to the shell during a firing process, the fixturing system comprising: a fixturing plate comprising at least one aperture defined therein, the fixturing plate sized to be inserted within the shell cavity and including an outer boundary that is shaped at least partially complementary to an inner surface of the shell; and at least one fixturing rod sized to be inserted through the aperture of the fixturing plate such that the at least one fixturing rod extends into the cavity and between the fixturing plate and the core to facilitate securing a relative position of the core during a firing process.

[0070] 10. The mold system in accordance with any preceding clause, wherein the fixturing system further comprises a fixturing insert sized to be positioned in the cavity between the core and the shell.

[0071] 11. The mold system in accordance with any preceding clause, wherein the fixturing insert has a height that is approximately the same as a height of the core.

[0072] 12. The mold system in accordance with any preceding clause, wherein the fixturing plate aperture is defined by an outer boundary that is sized and shaped substantially complementary to an outer surface of the fixturing rod.

[0073] 13. The mold system in accordance with any preceding clause, wherein the at least one fixturing insert comprises an outer surface having a portion that is shaped substantially complimentary to a portion of an outer surface of the core.

[0074] 14. The mold system in accordance with any preceding clause, wherein the fixturing system further comprises a first fixturing insert and a second fixturing insert positioned on an opposite side of the core from the first fixturing insert.

[0075] 15. A method of forming a mold for forming a cast component, the method comprising: positioning a fixturing plate within a cavity defined by a shell of a mold used to form the component, wherein the fixturing plate includes at least one aperture defined therein; and inserting a securing member at least partially through the aperture such that the securing member extends between the fixturing plate and a core positioned within the shell, and such that the securing member contacts the core.

[0076] 16. The method in accordance with any preceding clause, wherein the method further comprises positioning a fixturing insert within the cavity between the core and the shell.

[0077] 17. The method in accordance with any preceding clause, wherein the method further comprises: firing, simultaneously, the shell, the core, the fixturing plate and the securing member; and removing the fixturing plate from within the cavity. [0078] 18. The method in accordance with any preceding clause, wherein the fixturing plate is positioned within cavity without damaging the shell.

[0079] 19. The method in accordance with any preceding clause, wherein positioning the fixturing insert includes positioning the fixturing insert within the cavity without the fixturing insert contacting the shell.

[0080] 20. The method in accordance with any preceding clause, wherein inserting the securing member includes inserting the securing member within the cavity without the securing member contacting the shell

[0081] The above description is meant to be exemplary only, and one skilled in the art will recognize that changes may be made to the embodiments described without departing from the scope of the invention disclosed. Modifications, which fall within the scope of the present invention, will be apparent to those skilled in the art, in light of a review of this disclosure, and such modifications are intended to fall within the appended claims.

[0082] Although specific features of various embodiments of the disclosure may be shown in some drawings and not in others, this is for convenience only. In accordance with the principles of the disclosure, any feature of a drawing may be referenced and/or claimed in combination with any feature of any other drawing.

[0083] This written description uses examples to disclose the embodiments of systems and methods, including the best mode, and also to enable any person skilled in the art to practice the systems and methods, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the systems and methods is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.

Claims

1. A fixturing system for use with a mold used for fabricating a component, the fixturing system comprising: a fixturing plate including at least one aperture defined therein, the fixturing plate sized to be inserted within a cavity defined within a shell of the mold, the fixturing plate further having an outer boundary that is shaped at least partially complementary to an inner surface of the shell; and at least one of a fixturing rod sized to be inserted through the aperture of the fixturing plate such that the at least one fixturing rod extends into the cavity and between the fixturing plate and a core of the mold to facilitate securing a relative position of the core during a firing process.

2. The system in accordance with Claim 1, wherein the fixturing system further comprises: a fixturing insert that is sized to be positioned within the cavity between the core and the shell.

3. The system in accordance with Claim 1, wherein the fixturing insert has a height that is approximately the same as a height of the core.

4. The system in accordance with Claim 1, wherein the aperture of the fixturing plate is defined by an outer boundary that is sized and shaped substantially complementary to an outer surface of the fixturing rod.

5. The system in accordance with Claim 2, wherein the at least one fixturing insert includes an outer surface, wherein a portion of the outer surface is shaped substantially complimentary to a portion of an outer surface of the core.

6. The system in accordance with Claim 1, wherein the fixturing system further includes a first fixturing insert and a second fixturing insert that is positioned on an opposite side of the core from the first fixturing insert.

7. The system in accordance with Claim 1, wherein the fixturing plate includes at least a first aperture having a first diameter and a second aperture having a second diameter that is different from the first diameter.

8. The system in accordance with Claim 1, wherein the fixturing plate is defined by an outer boundary that is shaped substantially complementary to an inner surface of the cavity, wherein the fixturing plate is positioned on a shelf protruding from the shell.

9. A mold system for use in fabricating a component, the mold system comprising: a mold for use in fabricating the component, the mold comprising a shell defining a cavity and a core positioned within the cavity; and a fixturing system for use in securing a position of the core relative to the shell during a firing process, the fixturing system comprising: a fixturing plate comprising at least one aperture defined therein, the fixturing plate sized to be inserted within the shell cavity and including an outer boundary that is shaped at least partially complementary to an inner surface of the shell; and at least one fixturing rod sized to be inserted through the aperture of the fixturing plate such that the at least one fixturing rod extends into the cavity and between the fixturing plate and the core to facilitate securing a relative position of the core during a firing process.

10. The mold system in accordance with Claim 9, wherein the fixturing system further comprises a fixturing insert sized to be positioned in the cavity between the core and the shell.

11. The mold system in accordance with Claim 9, wherein the fixturing insert has a height that is approximately the same as a height of the core.

12. The mold system in accordance with Claim 9, wherein the fixturing plate aperture is defined by an outer boundary that is sized and shaped substantially complementary to an outer surface of the fixturing rod.

13. The mold system in accordance with Claim 9, wherein the at least one fixturing insert comprises an outer surface having a portion that is shaped substantially complimentary to a portion of an outer surface of the core.

14. The mold system in accordance with Claim 9, wherein the fixturing system further comprises a first fixturing insert and a second fixturing insert positioned on an opposite side of the core from the first fixturing insert.

15. A method of forming a mold for forming a cast component, the method comprising: positioning a fixturing plate within a cavity defined by a shell of a mold used to form the component, wherein the fixturing plate includes at least one aperture defined therein; and inserting a securing member at least partially through the aperture such that the securing member extends between the fixturing plate and a core positioned within the shell, and such that the securing member contacts the core.

16. The method in accordance with Claim 15, wherein the method further comprises positioning a fixturing insert within the cavity between the core and the shell.

17. The method in accordance with Claim 15, wherein the method further comprises: firing, simultaneously, the shell, the core, the fixturing plate and the securing member; and removing the fixturing plate from within the cavity.

18. The method in accordance with Claim 15, wherein the fixturing plate is positioned within cavity without damaging the shell.

19. The method in accordance with Claim 16, wherein positioning the fixturing insert includes positioning the fixturing insert within the cavity without the fixturing insert contacting the shell.

20. The method in accordance with Claim 15, wherein inserting the securing member includes inserting the securing member within the cavity without the securing member contacting the shell.