Sand casting hybrid tooling pattern plate manufacturing by direct additive manufacturing on a planar surf

Abstract

A method of manufacturing a sand casting hybrid tooling pattern plate used to form a mold in foundry sand includes providing a base plate having a planar surface, creating a surface condition on the planar surface of the base plate for subsequent additive manufacturing directly on the surface, and forming, via additive manufacturing, a mold-cavity-forming pattern member on the planar surface of the base plate.

Description

Attorney Docket No. 208273-0014-W001SAND CASTING HYBRID TOOLING PATTERN PLATE AND METHOD OF MANUFACTURING THE SAME BY DIRECT ADDITIVE MANUFACTURING ON A PLANAR SURFACE OF A PLATECROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 701,667, filed October 1, 2024, the entire contents of which is incorporated herein by reference.FIELD

[0002] Embodiments relate to sand casting hybrid tooling pattern plate and method of manufacturing the same.BACKGROUND OF THE DISCLOSURE

[0003] To produce parts in metals via sand casting methods, it is necessary to compress prepared foundry sand with tooling to form a suitable mold, with cavities into which metal may be poured.

[0004] This requires tooling representative of the desired part which is the ‘master’ or ‘pattern’ from which the mold is being made. To produce both sides of a mold at once, a pattern usually takes the form of a ‘match plate’, a plate with the top and bottom part geometries mounted on their respective sides. This plate is traditionally either cut from a monolithic block of material, assembled from multiple machined components, or built up out of carved and handworked pieces of wood, tooling board, or other suitable materials worked and blended together to produce a suitable pattern against which to compress foundry sand to form molds.

[0005] The production of pattern plates by traditional methods is both time and labor intensive, and machining approaches require substantial material removal to achieve desired part forms.

[0006] For multi-component patterns, assembly usually requires extensive use of fasteners to combine the parts together, which introduces a number of knock-on effects and concerns which can require considerable additional labor and cost to resolve.Attorney Docket No. 208273-0014-W001SUMMARY

[0007] In some aspects, the techniques described herein relate to a method of manufacturing a sand casting hybrid tooling pattern plate, the tooling pattern plate used to form a mold in foundry sand, the method including: providing a base plate having a planar surface; creating a surface condition on the planar surface of the base plate for subsequent additive manufacturing directly on the surface; and forming, via additive manufacturing, a mold-cavity-forming pattern member on the planar surface of the base plate.

[0008] In some aspects, the techniques described herein relate to a method, wherein the base plate includes a metal.

[0009] In some aspects, the techniques described herein relate to a method, wherein the base plate includes aluminum or steel.

[0010] In some aspects, the techniques described herein relate to a method, wherein the base plate includes a polymer.

[0011] In some aspects, the techniques described herein relate to a method, wherein the polymer includes chopped carbon fibers.

[0012] In some aspects, the techniques described herein relate to a method, wherein forming, via additive manufacturing, the pattern member includes forming, via additive manufacturing, the pattern member from a photopolymer.

[0013] In some aspects, the techniques described herein relate to a method, wherein the photopolymer has a compressive and / or flexural strength to resist deformation and / or failure under a pressure of up to 200psi.

[0014] In some aspects, the techniques described herein relate to a method, wherein creating the surface condition includes creating a surface roughness on the planar surface.

[0015] In some aspects, the techniques described herein relate to a method, wherein the surface roughness is created via a process selected from the group consisting of laser etching, chemical etching, media tumbling, media blasting, peening, machining, abrading, and directAttorney Docket No. 208273-0014-W001 application of material deposition onto as-formed surfaces through near-net processes such as casting.

[0016] In some aspects, the techniques described herein relate to a method, wherein the surface roughness is created on an entirety of the planar surface.

[0017] In some aspects, the techniques described herein relate to a method, further including applying a ceramic coating to the base plate.

[0018] In some aspects, the techniques described herein relate to a method, wherein the planar surface of the base plate is a first planar surface of the base plate and the mold-cavity- forming pattern member is a first mold-cavity-forming pattern member, the method further including: providing a second planar surface on the base plate, opposite the first planar surface, creating a surface condition on the second planar surface of the base plate for subsequent additive manufacturing directly on the second surface, and forming, via additive manufacturing, a second mold-cavity-forming pattern member on the second planar surface of the base plate.

[0019] In some aspects, the techniques described herein relate to a method, wherein the first mold-cavity -forming pattern member and the second mold-cavity -forming pattern member are formed of dissimilar materials.

[0020] In some aspects, the techniques described herein relate to a method, wherein creating the surface condition on the first planar surface is dissimilar from creating the surface condition on the second planar surface.

[0021] In some aspects, the techniques described herein relate to a method, wherein the surface condition of the first surface is created via a process selected from the group consisting of laser etching, chemical etching, media tumbling, media blasting, peening, machining, abrading, and direct application of material deposition onto as-formed surfaces through near-net processes such as casting, and wherein the surface condition of the second surface is created via a second process different from the first process and selected from the group consisting of laser etching, chemical etching, media tumbling, media blasting, peening, machining, abrading, andAttorney Docket No. 208273-0014-W001 direct application of material deposition onto as-formed surfaces through near-net processes such as casting.BRIEF DESCRIPTION OF THE DRAWINGS

[0022] FIG. l is a method for manufacturing a sand casting hybrid tooling pattern plate.

[0023] FIG. 2 is a schematic view of the sand casting hybrid tooling pattern plate formed via the method of FIG. 1.DETAILED DESCRIPTION

[0024] Before any embodiments are explained in detail, it is to be understood that the application is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. Other embodiments than those described below, are capable of being practiced or of being carried out in various ways.

[0025] FIG. 1 illustrates a method 100 of manufacturing a sand casting hybrid tooling pattern plate (e.g., hybrid pattern plate). The resulting tooling pattern plate 200 (FIG. 2), once manufactured, is used to form a mold from foundry sand. The method 100 for manufacturing the sand casting hybrid tooling pattern plate may include, at step 104, providing a base plate 204 having a first surface 204a and a second surface 204b opposite the first surface 204a. Each of the first surface 204a and the second surface 204b are flat or planar. The method 100 may further include, at step 108, creating a surface condition (e.g., surface roughness, texture, etc.) on at least one of the planar surfaces 204a, 204b of the base plate 204. The method 100 may further include, at step 112, forming, via additive manufacturing, a pattern member 300a, 300b onto at least one of the planar surfaces of the base plate 204. Accordingly, once the material of the pattern member 300a, 300b is cured, the pattern member 300a, 300b may be directly coupled to the planar surfaces 204a, 204b of the base plate 204. Additionally, preferably, the pattern member 300a, 300b is coupled to the base plate 204 with minimal or no mechanical fasteners. In addition, direct printing of pattern member 300a, 300b onto the base plate 204 can allow for minimal to noAttorney Docket No. 208273-0014-W001 use of an adhesive as described herein. Collectively, the pattern members 300a, 300b make up a pattern of the tooling pattern plate 200, which is used to create the mold.

[0026] Though “additive manufacturing” is an industry standard term (ASTM F2792), additive manufacturing encompasses various manufacturing and prototyping techniques known under a variety of names, including freeform fabrication, 3D printing, rapid prototyping / tooling, and the like. Additive manufacturing techniques are capable of fabricating complex components from a wide variety of materials. Generally, a freestanding object can be fabricated from a computer aided design (CAD) model. A particular type of additive manufacturing process uses light to solidify a photopolymer, creating a solid three-dimensional object.

[0027] The method 100 may further include forming the base plate 204 from a metallic material (e.g., a flat plate stock). Accordingly, the base plate 204 can include a metal. For example, the base plate 204 may be formed via casting, forging, extruding, rolling, or machining the base plate 204 from a metallic material, such as aluminum, a magnesium alloy (e.g., Dowmetal), cast iron, or steel, although any suitable metal may be used.

[0028] The method 100 may further include forming the base plate 204 from a nonmetallic material. For example, in some embodiments, the base plate 204 may be formed, via any suitable process (such as machining), from wood. In another example, the base plate 204 may be formed via additive manufacturing using a polymer material. Accordingly, the base plate 204 can include a polymer. Any suitable additive manufacturing technique may be used to create the base plate 204. Additionally, the base plate 204 may be formed in any suitable way. For example, the base plate 204 can be made via filament or pellet-fed extrusion deposition, sheet lamination, directed-energy deposition, selective laser sintering, continuous fiber placement, material jetting, casting, injection molding, compression molding, thermoforming, or machined from stock, to name some potential techniques.

[0029] If used, the polymer used for the base plate 204 is not generally limited, and can be any polymer that has the requisite mechanical properties to function as a base plate 204 in a sand casting tool pattern plate. For example, match plates need sufficient flexural and compressive strength to tolerate up to ~150psi transient loads, thermal operating range to maintain strength in hot foundry conditions and processing steps up to 150°F, abrasion resistance to foundry sandAttorney Docket No. 208273-0014-W001 with a minimum ASTM-D3363 rating of 8H, and stiffness to resist deflection under uneven sand packing. Example polymers which can be used include, but are not limited to nylons, PET, PPA, PEEK, PEKK, PC, ASA, ABS, and UHMW. The polymer can be used neat or compounded with an additive such as reinforcing spherical, rough, or fibrous additives. Compounded polymers may also be referred to as polymer composites. In embodiments where the polymer is a polymer composite, the polymer can include at least one other material that can improve mechanical properties of the polymer. An example material includes, but is not limited to, a fiber (e.g., a reinforcing fiber). The fiber can be suspended or spread out in a polymer matrix. Example fibers include, but are not limited to, glass, carbon, basalt, aramid, and combinations thereof. In some embodiments, the polymer includes an additive, such as but not limited to, chopped carbon fibers.

[0030] With respect to step 108, creating a surface condition may include creating a surface roughness on one or both of the planar surfaces 204a, 204b. The surface roughness may be created via, e.g., laser etching, chemical etching, media tumbling or blasting, peening, machining, abrading or direct application of material deposition onto as-formed surfaces through near-net processes such as casting, or a combination of these. In some embodiments, the surface roughness may also be created on an entirety or a portion of the respective surface 204a, 204b. In some embodiments, a dissimilar surface roughness may be provided on the first surface 204a and the second surface 204b. In other embodiments, a similar surface roughness may be created on each (e.g., via a same method).

[0031] In some embodiments, step 108 may be omitted if the planar surfaces 204a, 204b of the base plate 204 are sufficient for adhesion by the material of the pattern members 300a, 300b. In other embodiments, step 108 may be omitted if the base plate 204 is formed in such a way that the planar surfaces 204a, 204b thereof naturally have a suitable surface roughness / texture. For example, if the base plate 204 is formed via SLS additive manufacturing the planar surfaces 204a, 204b of the resulting base plate 204 may have an inherent surfaces roughness / texture that that is sufficient for adhesion by the material of the pattern members 300a, 300b. In other embodiments, step 108 may be omitted and replaced by a step of applying a coating or film of material onto the planar surfaces 204a, 204b suitably promotes adhesion by the material of the pattern members 300a, 300b.Attorney Docket No. 208273-0014-W001

[0032] With respect to step 112, in some embodiments, the pattern members 300a, 300b may be formed directly on the planar surfaces 204a, 204b of the base plate 204 such that the pattern member 300a, 300b is coupled to the base plate 204 and extends therefrom. As shown in FIG. 2, a first pattern member 300a is formed directly on the first planar surface 204a and a second pattern member 300b is formed directly on the second planar surface 204b. In some embodiments, the first and second pattern members 300a, 300b are made of dissimilar materials. In other embodiments, there may be pattern members on only the first or second planar surface 204a, 204b. In other embodiments, there may be more than one pattern member on either the first or second planar surface 204a, 204b. Preferably, the pattern members 300a, 300b overly the surface condition such that the material of the pattern members 300a, 300b bonds with the respective planar surface 204a, 204b of the base plate 204.

[0033] With respect to step 112, in some embodiments, the pattern members 300a, 300b may be formed directly on the planar surfaces 204a, 204b of the base plate 204 from a material comprising a polymer. For example, the polymer may be a photopolymer, which can be used to form the pattern members 300a, 300b via large format vat photopolymerization. That is, the base plate 204 is positioned within the build vat such that the material of the pattern member 300a, 300b can be cured in place directly on the base plate 204. For beneficial interactions between the base plate 204 and the pattern members 300a, 300b and to aid in the overall integrity of the tooling pattern plate 200, the material of the base plate 204 should be compatible with the material used to form the pattern members 300a, 300b, as well as the constituents of unreacted monomers, oligomers and photoinitiators in the vat. That is, the material of the base plate 204 should retain the necessary structural integrity that the application requires while in the vat such that the material of the pattern members 300a, 300b can adequately bond and couple to the base plate 204. In some embodiments, the pattern members 300a, 300b may be formed from a polymer via other suitable additive manufacturing techniques other than vat photopolymerization. As used herein, a photopolymer system is a combination of monomers, oligomers, and suitable catalysts (photoinitiators) that can be cured into final polymer chains (e.g., transformed from a liquid state to a solid state) in the presence of an activating wavelength band of light that stimulates the photoinitiator in the polymer system, such as one or more of ultraviolet light, visible-light, or infrared-light. Photopolymers can be commercially purchasedAttorney Docket No. 208273-0014-W001 and can be derived from monofunctional and / or multifunctional monomers having different functional groups, which can comprise polymers systems such as, but not limited to, acrylates, methylacrylates, urethanes, and epoxies. The polymer used to form the pattern member 300a, 300b can have advantageous properties that make it useful for a sand casting tool pattern plate. For example, the polymer can have compressive and flexural strength to resist deformation and / or failure under sand-forming pressures up to 200psi, abrasion resistance to avoid erosion due to sand deposition at velocity, hardness to resist sand embedment at above mentioned pressures (200psi) and sufficient thermomechanical stability to resist deformation or softening in the foundry processing environment, which can reach temperatures up to 150°F. The polymer can have one or any combination of the foregoing properties.

[0034] The pattern of the resulting tooling pattern plate 200 creates cavities (e.g., negative features) within the mold cavity. In still other embodiments, any of the pattern members 300a, 300b may include one or more recesses (not shown) or grooves (not shown) that may be used to create positive features (e.g., ridges, lips, flanges, projections, etc.) of the mold cavity. The recesses / grooves may have any suitable size and shape.

[0035] Additionally, in some embodiments, either of the method 100 may further include applying a ceramic coating to the tooling pattern plate 200. The ceramic coating may aid in the durability of the tooling pattern plate 200. In some embodiments, the ceramic coating may be applied to all or a portion of the base plate 204, all or a portion of the pattern members 300a, 300b, or both. The ceramic coating increases the hardness of the tooling pattern plate 200, particularly the pattern members 300a, 300b. Additionally, over time, the ceramic coating can be reapplied to maintain the hardness of the tooling pattern plate with successive use. The ceramic coatings may include combinations of multiple different engineering ceramics, refractory resins, pigments, and other functional additives. An example commercially available and suitable ceramic coating includes, but is not limited to, formulations offered by CERAKOTE®. In some embodiments, the ceramic coating is comprised of a suitable polymer system such as, but not limited to, a polyurethane, epoxy, acrylate, methyl or phenyl modified silicone, utilized as a matrix material to form a composite coating with engineering ceramics, such as but not limited to, alumina, zirconia, carbides, and nitrides.Attorney Docket No. 208273-0014-W001

[0036] In some embodiments, the method includes applying a second ceramic coating. The second ceramic coating can be applied to at least a portion (e.g., surface) of the ceramic coating. The description of the ceramic coating can also be applied to the second ceramic coating. Embodiments that include the ceramic coating and the second ceramic coating can be used to assess wear of the tooling pattern plate 200. For example, the ceramic coating can include a pigment, and the second ceramic coating can include a pigment that is different from the pigment of the ceramic coating. As the second ceramic coating experiences wear and is removed from the tooling pattern plate 200, the pigment of the ceramic coating will become more visible. The change of color can be used to assess wear of the ceramic coating(s) and inform a user when the tooling pattern plate 200 requires additional application of a ceramic coating.

[0037] A conventional tooling pattern plate is often made entirely via machining. The time required to create a tooling pattern plate via machining alone is significant because small features and smooth surfaces require extensive process time and small tools to produce. Additionally, because the details are difficult to produce, mistakes during machining are common, and the cost to re-machine the tooling pattern plate is considerable. In contrast, the disclosed method (using additive and subtractive manufacturing) and the resulting tooling pattern plate 200 is an easier, faster, and more cost-effective production method for the tooling pattern plate 200. This is because using machining for only the base plate 204 reduces the complexity of the machining process, and using additive manufacturing for the pattern members (which include the details of the tooling pattern plate 200) is faster and easier. Accordingly, the disclosed method and resulting tooling pattern plate 200 allows for a reduction in raw materials costs, due to reducing required input starting material for machining portions of the assembly. Additionally, there is reduced labor and machine-time requirement to produce machined portions of the assembly, due to moving complex features to parts produced by additive manufacturing. Even further, modularity of the pattern members, allows for easier iterative upgrades / modifications to improve sand casting hybrid tooling design or with end-product design, and replacement in the case of failures.

[0038] ClausesAttorney Docket No. 208273-0014-W001

[0039] Clause 1. A method of manufacturing a sand casting hybrid tooling pattern plate, the tooling pattern plate used to form a mold in foundry sand, the method comprising: providing a base plate having a planar surface; creating a surface condition on the planar surface of the base plate for subsequent additive manufacturing directly on the surface; and forming, via additive manufacturing, a mold-cavity-forming pattern member on the planar surface of the base plate.

[0040] Clause 2. The method of clause 1, wherein the base plate comprises a metal.

[0041] Clause 3. The method of clause 2, wherein the base plate comprises aluminum or steel.

[0042] Clause 4. The method of clause 1, wherein the base plate comprises a polymer.

[0043] Clause 5. The method of clause 4, wherein the polymer comprises chopped carbon fibers.

[0044] Clause 6. The method of clause 1, wherein forming, via additive manufacturing, the pattern member includes forming, via additive manufacturing, the pattern member from a photopolymer.

[0045] Clause 7. The method of clause 6, wherein the photopolymer has a compressive and / or flexural strength to resist deformation and / or failure under a pressure of up to 200psi.

[0046] Clause 8. The method of clause 1, wherein creating the surface condition includes creating a surface roughness on the planar surface.

[0047] Clause 9. The method of clause 8, wherein the surface roughness is created via a process selected from the group consisting of laser etching, chemical etching, media tumbling, media blasting, peening, machining, abrading, and direct application of material deposition onto as-formed surfaces through near-net processes such as casting.

[0048] Clause 10. The method of clause 8, wherein the surface roughness is created on an entirety of the planar surface.Attorney Docket No. 208273-0014-W001

[0049] Clause 11. The method of clause 1, further comprising applying a ceramic coating to the base plate.

[0050] Clause 12. The method of clause 1, wherein the planar surface of the base plate is a first planar surface of the base plate and the mold-cavity-forming pattern member is a first moldcavity-forming pattern member, the method further comprising: providing a second planar surface on the base plate, opposite the first planar surface, creating a surface condition on the second planar surface of the base plate for subsequent additive manufacturing directly on the second surface, and forming, via additive manufacturing, a second mold-cavity-forming pattern member on the second planar surface of the base plate.

[0051] Clause 13. The method of clause 12, wherein the first mold-cavity-forming pattern member and the second mold-cavity-forming pattern member are formed of dissimilar materials.

[0052] Clause 14. The method of clause 12, wherein creating the surface condition on the first planar surface is dissimilar from creating the surface condition on the second planar surface.

[0053] Clause 15. The method of clause 14, wherein the surface condition of the first surface is created via a process selected from the group consisting of laser etching, chemical etching, media tumbling, media blasting, peening, machining, abrading, and direct application of material deposition onto as-formed surfaces through near-net processes such as casting, and wherein the surface condition of the second surface is created via a second process different from the first process and selected from the group consisting of laser etching, chemical etching, media tumbling, media blasting, peening, machining, abrading, and direct application of material deposition onto as-formed surfaces through near-net processes such as casting.

[0054] Although the invention has been described in detail with reference to certain preferred embodiments, variations and modifications exist within the scope and spirit of one or more independent aspects of the invention as described.

[0055] Various features of the invention are set forth in the following claims.

Claims

Attorney Docket No. 208273-0014-W001CLAIMSWhat is claimed is:

1. A method of manufacturing a sand casting hybrid tooling pattern plate, the tooling pattern plate used to form a mold in foundry sand, the method comprising: providing a base plate having a planar surface; creating a surface condition on the planar surface of the base plate for subsequent additive manufacturing directly on the surface; and forming, via additive manufacturing, a mold-cavity-forming pattern member on the planar surface of the base plate.

2. The method of claim 1, wherein the base plate comprises a metal.

3. The method of claim 2, wherein the base plate comprises aluminum or steel.

4. The method of claim 1, wherein the base plate comprises a polymer.

5. The method of claim 4, wherein the polymer comprises chopped carbon fibers.

6. The method of claim 1, wherein forming, via additive manufacturing, the pattern member includes forming, via additive manufacturing, the pattern member from a photopolymer.

7. The method of claim 6, wherein the photopolymer has a compressive and / or flexural strength to resist deformation and / or failure under a pressure of up to 200psi.

8. The method of claim 1, wherein creating the surface condition includes creating a surface roughness on the planar surface.

9. The method of claim 8, wherein the surface roughness is created via a process selected from the group consisting of laser etching, chemical etching, media tumbling, media blasting, peening, machining, abrading, and direct application of material deposition onto as-formed surfaces through near-net processes such as casting.Attorney Docket No. 208273-0014-W00110. The method of claim 8, wherein the surface roughness is created on an entirety of the planar surface.

11. The method of claim 1, further comprising applying a ceramic coating to the base plate.

12. The method of claim 1, wherein the planar surface of the base plate is a first planar surface of the base plate and the mold-cavity -forming pattern member is a first mold-cavity- forming pattern member, the method further comprising: providing a second planar surface on the base plate, opposite the first planar surface, creating a surface condition on the second planar surface of the base plate for subsequent additive manufacturing directly on the second surface, and forming, via additive manufacturing, a second mold-cavity-forming pattern member on the second planar surface of the base plate.

13. The method of claim 12, wherein the first mold-cavity-forming pattern member and the second mold-cavity-forming pattern member are formed of dissimilar materials.

14. The method of claim 12, wherein creating the surface condition on the first planar surface is dissimilar from creating the surface condition on the second planar surface.

15. The method of claim 14, wherein the surface condition of the first surface is created via a process selected from the group consisting of laser etching, chemical etching, media tumbling, media blasting, peening, machining, abrading, and direct application of material deposition onto as-formed surfaces through near-net processes such as casting, and wherein the surface condition of the second surface is created via a second process different from the first process and selected from the group consisting of laser etching, chemical etching, media tumbling, media blasting, peening, machining, abrading, and direct application of material deposition onto as-formed surfaces through near-net processes such as casting.

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