Manufacture of homogeneous titanium alloy parts via laminated object manufacturing

Abstract

Methods and systems for the laminated object manufacturing of homogenized titanium alloy parts. Some embodiments include a method that includes stacking a plurality of metal sheets, wherein at least one sheet comprises majority titanium and the remaining sheets comprise a distinct elemental composition from the at least one sheet; and homogenizing the stack, wherein the homogenized stack comprises a titanium alloy of a desired composition.

Description

MANUFACTURE OF HOMOGENEOUS TITANIUM ALLOY PARTS VIA LAMINATED OBJECT MANUFACTURINGCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims the benefit of and priority to United States Provisional Application No. 63 / 665,119, filed on June 27, 2024, and PCT Application No. PCT / US24 / 31709, filed on May 30, 2024, the entire disclosure of each of which is hereby incorporated by reference as if set forth in its entirety herein.TECHNICAL FIELD

[0002] Embodiments described herein generally relate to methods and apparatus for producing titanium alloy parts, and more specifically to the manufacture of homogeneous titanium alloy parts via laminated object manufacturing.BACKGROUND

[0003] Titanium and its alloys are widely used in various industrial applications due to their properties such as high strength, corrosion resistance, and biocompatibility. Ti-6A1-4V, for example, is commonly used in structural aerospace components, offering a favorable balance of strength and weight.

[0004] However, the manufacture of titanium alloys for industrial parts faces several challenges. Titanium has a relatively high melting point (over 1600°C), low thermal conductivity, and a tendency to react with tooling and atmospheric gases at elevated temperatures. These characteristics contribute to the difficulty and cost of conventional manufacturing processes, such as casting and forging, particularly when producing parts with intricate geometries or internal features.

[0005] Accordingly, a need exists for improved methods of manufacturing titanium alloy parts.SUMMARY

[0006] This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description section. This summary is not intended to identify or exclude key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

[0007] In some aspects, the techniques described herein relate to a method to produce a homogenized titanium alloy part, the method including stacking a plurality of metal sheets, wherein at least one sheet includes majority titanium and the remaining sheets include a distinctelemental composition from the at least one sheet; and homogenizing the stack, wherein the homogenized stack includes a titanium alloy of a desired composition.

[0008] In some aspects, at least one of the remaining sheets includes majority aluminum or aluminum -vanadium .

[0009] In some aspects, at least one sheet includes a core layer clad with at least one clad layer on at least one side of the core layer.

[0010] In some aspects, the clad layer is bonded to the core layer before homogenizing the stack.

[0011] In some aspects, at least one sheet includes a core layer clad with at least two clad layers on both sides of the core layer, and wherein the clad layers differ in composition.

[0012] In some aspects, the remaining sheets include at least one mobile element.

[0013] In some aspects, the mobile element is present in different concentrations within at least two metal sheets.

[0014] In some aspects, homogenizing the stack equalizes the concentration of the mobile element across all the metal sheets.

[0015] In some aspects, homogenizing the stack includes heating the stack so that the mobile element diffuses without exceeding the melting point of any of the metal sheets.

[0016] In some aspects, the mobile element includes at least one of aluminum, tin, zirconium, molybdenum, niobium, chromium, iron, copper, nickel, or vanadium.

[0017] In some aspects, homogenizing the stack includes heating the stack.

[0018] In some aspects, each metal sheet includes at least one part region and at least one support region.

[0019] In some aspects, at least one element is present in substantially equal concentrations in at least two metal sheets, and wherein the element does not diffuse in significant quantities during the homogenization of the stack.

[0020] In some aspects, the techniques described herein relate to a system for manufacturing a laminated object, the system including a laminated object manufacturing device configured to stack a plurality of metal sheets, wherein at least one sheet includes majority titanium and the remaining sheets include a distinct elemental composition from the at least one sheet; and a pressorconfigured to apply at least one of pressure or heat to homogenize the stack, wherein the homogenized stack includes a titanium alloy of a desired composition.

[0021] In some aspects, the pressor is further configured to bond the metal sheets together before homogenizing the stack.

[0022] In some aspects, at least one of the remaining sheets includes majority aluminum or aluminum -vanadium .

[0023] In some aspects, at least one sheet includes a core layer clad with at least one clad layer on at least one side of the core layer.

[0024] In some aspects, the remaining sheets include at least one mobile element.

[0025] In some aspects, homogenizing the stack includes heating the stack.

[0026] In some aspects, the techniques described herein relate to a homogenized titanium alloy part formed via a laminated object manufacturing process, the process including stacking a plurality of metal sheets, wherein at least one sheet includes majority titanium and the remaining sheets include a distinct elemental composition from the at least one sheet; and homogenizing the stack, wherein the homogenized stack includes a titanium alloy of a desired composition.

[0027] In some aspects, the techniques described herein relate to a cladded metal sheet, the sheet having a core comprising the balance Ti, between 3.5-4.5 wt.% V, and between 0-6.75 wt.% Al; a clad comprising the balance Al and between 3.5-4.5 wt.% V; and the homogenized cladded metal sheet having an average composition corresponding to the specifications for a grade 5 titanium alloy.

[0028] In some aspects the trace elements in the core and clad compositions include at most 0.3 wt.% Fe, at most 0.2 wt.% O, at most 0.08 wt.% C, at most 0.05 wt.% N, at most 0.015 wt.% H, at most 0.005 wt.% Y, and with any other elemental species present at less than 0.05 wt.% and the total of all other elements less than 0.3 wt.%.

[0029] In some aspects the clad is at most 9% of the total thickness of the cladded metal sheet.

[0030] In some aspects the sheet thickness is between 25 pm and 1000 pm.

[0031] In some aspects the core is the first layer of the metal sheet and the clad is the second layer of the metal sheet.

[0032] In some aspects the first layer forms a first clad of the metal sheet, a second layer forms the core of the metal sheet, and a third layer forms a second clad of the metal sheet.

[0033] In some aspects, the techniques described herein relate to a cladded metal sheet, the sheet having a core comprising the balance Ti, between 0-6.0 wt.% Al, and between 1.0-4.0 wt.% Sn; a clad comprising the balance Al and between 1.0-4.0 wt.% Sn; and the homogenized cladded metal sheet having an average composition corresponding to the specifications for a grade 6 titanium alloy.

[0034] In some aspects the trace elements in the core and clad are at most 0.08 wt.% C, at most 0.5 wt.% Fe, at most 0.02 wt.% H, at most 0.05 wt.% N, at most 0.2 wt.% O, and with any other elemental species present at less than 0.05 wt.% and the total of all other elements less than 0.3 wt.%.

[0035] In some aspects, the techniques described herein relate to a cladded metal sheet, the sheet having a core comprising the balance Ti and between 1.0-4.0 wt.% V and between 0-3.5 wt.% Al; a clad comprising the balance Al and between 1.0-4.0 wt.% V; and the homogenized cladded metal sheet having an average composition corresponding to the specifications for a grade 9 titanium alloy.

[0036] In some aspects the trace elements in the core and clad are at most 0.08 wt.% C, at most 0.25 wt.% Fe, at most 0.015 wt.% H, at most 0.03 wt.% N, at most 0.15 wt.% O, and with any other elemental species present at less than 0.05 wt.% and the total of all other elements less than 0.3 wt.%.

[0037] In some aspects, the techniques described herein relate to a cladded metal sheet, the sheet having a core comprising the balance Ti, between 0.04-0.1 wt.% Pd, between 1.0-4.0 wt.% V, and between 0-3.5 wt.% Al; a clad comprising the balance Al, between 0-0.08 wt.% Pd, and between 1.0-4.0 wt.% V; and the homogenized cladded metal sheet having an average composition corresponding to the specifications for a grade 18 titanium alloy.

[0038] In some aspects the trace elements in the core and clad are at most 0.08 wt.% C, at most 0.25 wt.% Fe, at most 0.015 wt.% H, at most 0.03 wt.% N, at most 0.15 wt.% O, and with any other elemental species present at less than 0.05 wt.% and the total of all other elements less than 0.3 wt.%.

[0039] In some aspects, the techniques described herein relate to a cladded metal sheet, the sheet having a core comprising the balance Ti, between 1.2-1.8 wt.% Fe, between 0.2-0.3 wt.% O, between 1.0-3.0 wt.% V, and between 0-4.5 wt.% Al; a clad comprising the balance Al, and between 1.0-3.0 wt.% V; and the homogenized cladded metal sheet having an average composition corresponding to the specifications for a grade 38 titanium alloy.

[0040] In some aspects the trace elements in the core and clad are at most 0.08 wt.% C, at most 0.015 wt.% H, at most 0.03 wt.% N, and with any other elemental species present at less than 0.05 wt.% and the total of all other elements less than 0.3 wt.%.

[0041] In some aspects, the techniques described herein relate to a cladded metal sheet, the sheet having a core comprising the balance Ti, between 0-6.2 wt.% Al, between 5.8-6.2 wt.% Mo, 1.8-2.2 wt.% Sn, and 3.8-4.2 wt.% Zr; a clad comprising the balance Al, between 5.8-6.2 wt.% Mo, 1.8-2.2 wt.% Sn, and 3.8-4.2 wt.% Zr; and the homogenized cladded metal sheet having an average composition corresponding to the specifications for a Ti-6246 titanium alloy.

[0042] In some aspects the trace elements in the core and clad at most 0.1 wt.% C, at most 0.45 wt.% Fe, at most 0.015 wt.% H, at most 0.035 wt.% K, at most 0.25 wt.% Mg, at most 0.04 wt.% N, at most 0.15 wt.% O, at most 0.35 wt.% Si, and with any other elemental species present at less than 0.05 wt.% and the total of all other elements less than 0.3 wt.%.

[0043] In some aspects, the techniques described herein relate to a cladded metal sheet, the sheet having a core comprising the balance Ti and trace elements; a clad comprising the balance Al and trace elements; and the homogenized cladded metal sheet having an average composition corresponding to the specifications for Ti3Al.

[0044] In some aspects the trace elements in the core and clad present at less than 0.05 wt.% and the total of all other elements less than 0.5 wt.%.

[0045] In some aspects the clad is between 16% and 34% of the total thickness of the cladded metal sheet.

[0046] In some aspects the core is the first layer of the metal sheet and the clad is the second layer of the metal sheet.

[0047] In some aspects the first layer forms a first clad of the metal sheet, a second layer forms the core of the metal sheet, and a third layer forms a second clad of the metal sheet.

[0048] In some aspects, the techniques described herein relate to a cladded metal sheet, the sheet having a core comprising the balance Ti and trace elements; a clad comprising the balance Al and trace elements; and the homogenized cladded metal sheet has an average composition corresponding to the specifications for TiAl.

[0049] In some aspects the trace elements in the core and clad present at less than 0.05 wt.% and the total of all other elements less than 0.5 wt.%.

[0050] In some aspects the clad is between 44% and 54% of the total thickness of the cladded metal sheet.

[0051] In some aspects the core is the first layer of the metal sheet and the clad is the second layer of the metal sheet.

[0052] In some aspects the first layer forms a first clad of the metal sheet, a second layer forms the core of the metal sheet, and a third layer forms a second clad of the metal sheet.

[0053] In some aspects, the techniques described herein relate to a cladded metal sheet, the sheet having a core comprising the balance Ti and trace elements; a clad comprising the balance Al and trace elements; and the homogenized cladded metal sheet has an average composition corresponding to the specifications for TiA12.

[0054] In some aspects the trace elements in the core and clad present at less than 0.05 wt.% and the total of all other elements less than 0.5 wt.%.

[0055] In some aspects the clad is between 64% and 66% of the total thickness of the cladded metal sheet.

[0056] In some aspects the core is the first layer of the metal sheet and the clad is the second layer of the metal sheet.

[0057] In some aspects the first layer forms a first clad of the metal sheet, a second layer forms the core of the metal sheet, and a third layer forms a second clad of the metal sheet.

[0058] In some aspects, the techniques described herein relate to a cladded metal sheet, the sheet having a core comprising the balance Ti and trace elements; a clad comprising the balance Al and trace elements; and the homogenized cladded metal sheet has an average composition corresponding to the specifications for TiA13.

[0059] In some aspects the trace elements in the core and clad present at less than 0.05 wt.% and the total of all other elements less than 0.5 wt.%.

[0060] In some aspects the clad is between 74% and 76% of the total thickness of the cladded metal sheet.

[0061] In some aspects the core is the first layer of the metal sheet and the clad is the second layer of the metal sheet.

[0062] In some aspects the first layer forms a first clad of the metal sheet, a second layer forms the core of the metal sheet, and a third layer forms a second clad of the metal sheet.BRIEF DESCRIPTION OF DRAWINGS

[0063] Non-limiting and non-exhaustive embodiments of this disclosure are described with reference to the following figures, wherein like reference numerals refer to like parts throughout the various views unless otherwise specified:

[0064] Figure 1 depicts a cross-section of a layered stack;

[0065] Figure 2 depicts a cross-section of another layered stack;

[0066] Figure 3 depicts a cross-section of still another layered stack;

[0067] Figure 4 depicts a cross-section of yet another layered stack;

[0068] Figure 5 depicts a cross-section of another layered stack;

[0069] Figure 6 depicts a table describing compositions of various titanium alloys that may be manufactured via this process; and

[0070] Figure 7 depicts a table describing the core and clad compositions of a roll-bonded titanium-aluminum sheet that may be homogenized to form a grade 5 titanium object.DETAILED DESCRIPTION

[0071] Various embodiments are described more fully below with reference to the accompanying drawings, which form a part hereof, and which show specific exemplary embodiments. However, the concepts of the present disclosure may be implemented in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided as part of a thorough and complete disclosure, to fully convey the scope of the concepts, techniques and implementations of the present disclosure to those skilled in the art. Embodiments may be practiced as methods, systems or devices. The following detailed description is, therefore, not to be taken in a limiting sense.

[0072] Reference in the specification to “one embodiment” or to “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiments is included in at least one example implementation or technique in accordance with the present disclosure. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment.

[0073] In addition, the language used in the specification has been principally selected for readability and instructional purposes and may not have been selected to delineate or circumscribe the disclosed subject matter. Accordingly, the present disclosure is intended to be illustrative, and not limiting, of the scope of the concepts discussed herein.Definitions

[0074] Unless otherwise specified, the following terms as used herein shall have the meanings as provided below:

[0075] The term “laminated object manufacturing” (LOM) refers to a method of manufacturing a part, containing additive and subtractive steps, beginning with contiguous sheets of material, and processing sheets sequentially to form a part.

[0076] The term “bonding” refers to the process through which the contiguous sheets of material are formed into a part. The workpiece is subjected to a combination of heat and applied force which form covalent and / or metallic bonds between the sheets of material, forming an object.

[0077] The term “workpiece” refers to a stack of metal sheets to be bonded into at least one part and at least one corresponding support structure.

[0078] The term “metal sheet” refers to a metal sheet or foil that is stacked in a workpiece. In some embodiments, the metal sheet may comprise a core layer and / or a clad layer. In some embodiments, the metal sheet may comprise at least one of titanium, aluminum, copper, magnesium, aluminum alloy, magnesium alloy, and / or titanium alloy.

[0079] The term “core layer” refers to a layer of a metal sheet that forms the core or central portion of the metal sheet.

[0080] The term “clad layer” refers to a layer of a metal sheet that clads a core layer on one or both sides.

[0081] The term “mobile element” refers to an element that is present in differing concentrations across the various layers and is capable of diffusing at a significant rate during thermal processing.Embodiments

[0082] Embodiments of this invention include methods and systems for producing titanium alloy parts via laminated object manufacturing (LOM). In LOM processes, a layered stack consisting of a plurality of metal sheets may be assembled. The stack may be assembled in a laminated fashion with the metal sheets. In this manner, the stack may be a layered workpiece assembled by depositing the metal sheets. The metal sheets may be patterned such that the pattern of the metal sheets partitions the workpiece into at least one support region and at least one part region. The metal sheets may be bonded in a heated press, a more complicated bonding machine comprising a heated press and a vacuum chamber, and / or a bonding machine of any configurationappropriate for laminated object manufacturing of metal parts. The metal sheets may be bonded by applying a mechanical force along at least one axial direction of the metal sheets.

[0083] In embodiments of this invention, a layered stack of metal sheets may be homogenized to produce titanium alloys of a desired compensation. The metal sheets may be stacked on top of each other so that each metal sheet acts as a layer of the layered stack. The layered stack may include at least two distinct elemental compositions. At least one of the layers within the stack may include a titanium-based alloy. The remaining layers may include titanium-based alloys and / or other compositions selected to contribute desired alloying elements to the final homogenized stack. The layered stack may be homogenized after the layers are stacked and optionally bonded.

[0084] In some implementations, the metal sheets may be pre-processed to aid the homogenization process and / or other downstream processes. For example, the metal sheets may undergo surface cleaning (e.g., to remove containments), chemical treatments, surface coating treatments (e.g., to promote bonding), and / or surface texturing or patterning.

[0085] In some embodiments, the layered stack may include at least one mobile element. The mobile element may be an alloying element that is not titanium. The layered stack may be subjected to a homogenization process, during which the mobile element may diffuse across all the layers (and / or at least a portion) of the layered stack. This may equalize the concentration of the mobile element across the layers of the layered stack so that the layered stack includes a substantially uniform distribution of the mobile element. The mobile element may be selected based on at least one characteristic of the mobile element, such as a rate of diffusion at a desired temperature, a melting point (e.g., relative to titanium), a solubility level, and / or a thermodynamic compatibility level. For example, a mobile element with a high rate of diffusion may be selected.

[0086] In some embodiments, the layered stack may include at least one non-mobile element. The non-mobile element may resist diffusion in significant quantities during the homogenization process. For example, the non-mobile element may already be present in substantially equal concentrations across the distinct elemental compositions. In other examples, the non-mobile element may remain spatially localized or unevenly distributed after the homogenization process.

[0087] In some embodiments, the mobile element may be aluminum. Other exemplary mobile elements may include, but are not limited to, tin, zirconium, molybdenum, niobium, chromium, iron, copper, nickel, and / or vanadium. In some embodiments, at least two mobile elements may be used in combination to produce a desired homogenous structure.

[0088] In some embodiments, the concentration of specific alloying elements, such as vanadium or molybdenum, may be selected in at least one layer such that the final homogenized concentration of the elements falls within a defined range. For example, the vanadium content in at least one layer may be pre-selected so that the homogenized concentration falls within the 3.5- 4.5% range, as defined for Ti-6A1-4V alloy compositions.

[0089] In some embodiments, other elements may be present as trace constituents, residual impurities, and / or minor alloying additions. Such elements may include iron in concentrations less than 0.3%, oxygen in concentrations less than 0.2%, carbon in concentrations less than 0.08%, nitrogen in concentrations less than 0.05%, hydrogen in concentrations less than 0.15%, yttrium in concentrations less than 0.005%, and / or the sum of all other elements in concentrations less than 0.3%.

[0090] In some embodiments, at least one metal sheet of the layered stack may include a core layer and / or at least one clad layer. The core layer may be clad on one or both sides by a clad layer. The clad layer may be bonded and / or otherwise adhered to the core layer (e.g., before stacking the sheets to form the layered stack). For example, the clad and core layers may undergo a bonding process such as roll bonding and / or diffusion bonding.

[0091] Figure 1 depicts a cross-section of a layered stack. As shown, the layered stack may include clad layers 101 that clad titanium sheets 102 on both sides. The clad layers 101 may be mobile element-rich layers. The clad layers 101 may be bonded to the surface of a titanium sheet 102 prior to stacking the titanium sheets 102. The stack may be subsequently homogenized into a titanium alloy part.

[0092] Figure 2 depicts a cross-section of a layered stack. As shown, the layered stack may include clad layers 201 that clad titanium sheets 202 on one side. The clad layers 201 may be mobile element-rich layers. The clad layers 201 may be bonded to the surface of a titanium sheet 202 prior to stacking the titanium sheets 202. The stack may be subsequently homogenized into a titanium alloy part.

[0093] In some examples, a first titanium alloy layer of a first composition (e.g., the core layer) may be clad with a second titanium alloy layer of a second composition (e.g., the clad layer) to create the layered stack. The first and / or second titanium alloy layers may be majority titanium. The thickness and composition of the first and / or second titanium alloy layers may be selected so that the average percentage of the alloying constituents across the layered stack conforms to a desired composition. The second titanium alloy layer may comprise up to 50% of the totalthickness of the layered stack and may be applied to one or both faces of the first titanium alloy layer.

[0094] In some examples, the core layer may be majority titanium while the clad layer may be majority aluminum. The aluminum-rich clad layer may act as the primary source of aluminum as a mobile element. The clad layer may be applied to one or both sides of the core layer. In some embodiments, the clad layer may comprise up to 50% of the total thickness of the layered stack.

[0095] In some embodiments, multiple metal sheets may be stacked to form the layered stack. The metal sheets may be bonded together and heat-treated to produce a homogenized stack with a desired composition. At least two of the sheets may have two distinct elemental compositions. The first elemental composition may be majority titanium. The second elemental composition may include at least one alloying element and have a lower melting point than the first elemental composition. For example, a first sheet that is majority titanium or aluminum-vanadium may be stacked with a second sheet that is majority aluminum or aluminum-vanadium. The thickness ratios and compositions of the sheets may be selected so that a high purity titanium sheet may be homogenized with sufficient aluminum (and / or other alloying elements such as but not limited to vanadium) to form a titanium alloy of a desired composition.

[0096] Figure 3 depicts a cross-section of a layered stack. The layered stack may include mobile element-rich sheets 301 stacked between titanium sheets 302. The sheets 301 may be majority aluminum. The stack may be subsequently homogenized into a titanium alloy part.

[0097] Figure 4 depicts a cross-section of a layered stack. The layered stack may include multiple mobile element-rich sheets of different compositions (e.g., sheets 401 and 402) stacked between titanium sheets 403. The sheets 401 and 402 may be majority aluminum or a mixture of aluminum and vanadium. The stack may be subsequently homogenized into a titanium alloy part.

[0098] Figure 5 depicts a cross-section of a layered stack. The layered stack may include titanium sheets 501 clad on both sides by clad layers 502 and 503. As shown, clad layers 502 and 503 may differ in composition. The stack may be subsequently homogenized into a titanium alloy part. When stacked, the clad layer 502 may contact the clad layer 503 on an adjacent sheet.

[0099] In some embodiments, the compositions of the layered stack are selected to homogenize to the composition of a desired grade of titanium alloy. In some embodiments, this is a commercially available titanium alloy. Figure 6 depicts a table 600 which outlines the desired composition specifications of various titanium alloys for manufacturing homogeneous titaniumalloy parts. To produce an alloy of the desired grade, compositions of the layers in the layer stack are selected so that the mathematical average matches a composition in the table 600.

[0100] In some embodiments, the desired composition may be a grade 5 (Ti-6A1-4V) alloy. A combination of metal sheets may be selected so that the desired composition matches specifications corresponding to Ti-6A1-4V. In one embodiment, a roll-bonded sheet stock may be configured with a core titanium layer and at least one aluminum layer corresponding to the formulations provided in Figure 7, table 700. In some embodiments, the aluminum-vanadium layer may be roll-bonded to both sides of the titanium core. For example, to produce a Ti-6A1-4V alloy, the total aluminum-vanadium layer thickness may be 4% to 9% of the total stack thickness to achieve the specification provided in table 600. Optionally, the vanadium concentration in each sheet may be 3.5% to 4.5%. Other alloying elements may be present, with their concentrations being no more than 0.05% per element and 0.3% in total.

[0101] In some embodiments, a Ti-6A1-4V alloy may be produced with a first sheet comprising titanium and vanadium, and a second sheet comprising aluminum. The thickness of the second sheet may be between 4% to 9% of the total stack. The vanadium content in the first sheet may be selected such that the average vanadium concentration is between 3.5% and 4.5% in the homogenized stack.

[0102] In some embodiments, the desired composition may be a titanium aluminide intermetallic alloy. The combination and thickness of titanium and aluminum metal sheets may be selected so that the desired composition matches the stoichiometric ratio of Ti3Al, TiAl, TiA12, or TiA13. These embodiments may have trace elements present at not more than 0.05% per species and 0.3% in total.

[0103] In some embodiments, the desired composition may be one of a range of aluminum containing titanium superalloys including, but not limited to Ti-6Al-7Nb, Ti-10V-2Fe-3Al, and Ti-5Al-2Sn-2Zr-4Cr-4Mo using the approach above. This process could be used by someone skilled in the art to produce a wide range of heat-treatable titanium-aluminum alloys, including one not even invented yet. In some embodiments, the process may be used by someone skilled in the art to produce a wide range of other heat-treatable titanium alloys with a second major element comprising at least one of the mobile elements such as aluminum, tin, zirconium, molybdenum, niobium, chromium, iron, copper, nickel, or vanadium.

[0104] In some embodiments, the layered stack may undergo a homogenization process to produce a homogenized stack. The homogenization process may produce a uniform titanium alloycomposition or any other desired composition. The layered stack may be homogenized after the metal sheets are stacked and optionally bonded together.

[0105] In some embodiments, the homogenization process may include heating the layered stack. The sheets may be heated to a temperature sufficient to promote diffusion of the mobile elements into the titanium-rich layers, while remaining below the melting point of any individual layer. For example, the homogenization temperature may be maintained between approximately 500°C and 950°C (e.g., for embodiments including aluminum-rich layers). In some embodiments, the layer with the lowest melting point may be the mobile element-rich layer, such as an aluminum- rich clad layer and / or metal sheet.

[0106] In some embodiments, the homogenization process may use a multi-step temperature profile. As the mobile elements diffuse across the layers, the minimum liquidus temperature of the layers may be increased in multiple steps, allowing for increased homogenization temperatures without reaching full melting. At least one of these steps may involve a controlled ramp-up in temperature so that the temperature is held below the melting point of the sheets.

[0107] In some embodiments, the homogenization process may be performed in a vacuum or inert gas environment, such as argon, to prevent surface oxidation or contamination. Following homogenization, the homogenized stack may be subjected to controlled cooling to achieve the desired composition. The resulting stack may include a substantially uniform composition.

[0108] In some embodiments, the homogenized stack may be further processed to produce various titanium alloy parts. For example, the homogenized stack may be formed, shaped, treated with heat, welded or joined with other parts, extruded, and / or rolled. In some embodiments, the metal sheets may be patterned such that the pattern of the metal sheets partitions the layered stack into at least one support region and / or at least one part region. Each part region may form a cross- sectional slice of the final part, such as an aerospace and / or automotive part.

[0109] In some embodiments, any of the aforementioned processes may be used to manufacture titanium alloy parts. For example, titanium sheets may be stacked with additional layers comprising aluminum, aluminum-vanadium, and / or other alloying elements, and subsequently bonded and homogenized into a uniform titanium part.Equivalents

[0110] The methods, systems, and devices discussed above are examples. Various configurations may omit, substitute, or add various procedures or components as appropriate. For instance, in alternative configurations, the methods may be performed in an order different fromthat described, and that various steps may be added, omitted, or combined. Also, features described with respect to certain configurations may be combined in various other configurations. Different aspects and elements of the configurations may be combined in a similar manner. Also, technology evolves and, thus, many of the elements are examples and do not limit the scope of the disclosure or claims.[OHl] Embodiments of the present disclosure, for example, are described above with reference to block diagrams and / or operational illustrations of methods, systems, and computer program products according to embodiments of the present disclosure. The functions / acts noted in the blocks may occur out of the order as shown in any flowchart. For example, two blocks shown in succession may in fact be executed substantially concurrent or the blocks may sometimes be executed in the reverse order, depending upon the functionality / acts involved. Additionally, or alternatively, not all of the blocks shown in any flowchart need to be performed and / or executed. For example, if a given flowchart has five blocks containing functions / acts, it may be the case that only three of the five blocks are performed and / or executed. In this example, any of the three of the five blocks may be performed and / or executed.

[0112] A statement that a value exceeds (or is more than) a first threshold value is equivalent to a statement that the value meets or exceeds a second threshold value that is slightly greater than the first threshold value, e.g., the second threshold value being one value higher than the first threshold value in the resolution of a relevant system. A statement that a value is less than (or is within) a first threshold value is equivalent to a statement that the value is less than or equal to a second threshold value that is slightly lower than the first threshold value, e.g., the second threshold value being one value lower than the first threshold value in the resolution of the relevant system.

[0113] Specific details are given in the description to provide a thorough understanding of example configurations (including implementations). However, configurations may be practiced without these specific details. This description provides example configurations only, and does not limit the scope, applicability, or configurations of the claims. Rather, the preceding description of the configurations will provide those skilled in the art with an enabling description for implementing described techniques. Various changes may be made in the function and arrangement of elements without departing from the spirit or scope of the disclosure.

[0114] Having described several example configurations, various modifications, alternative constructions, and equivalents may be used without departing from the spirit of the disclosure. For example, the above elements may be components of a larger system, wherein other rules may takeprecedence over or otherwise modify the application of various implementations or techniques of the present disclosure. Also, a number of steps may be undertaken before, during, or after the above elements are considered.

Claims

CLAIMSWhat is claimed is:

1. A method to produce a homogenized titanium alloy part, the method comprising: stacking a plurality of metal sheets, wherein at least one sheet comprises majority titanium and the remaining sheets comprise a distinct elemental composition from the at least one sheet; and homogenizing the stack, wherein the homogenized stack comprises a titanium alloy of a desired composition.

2. The method of claim 1 wherein at least one of the remaining sheets comprises majority aluminum or aluminum-vanadium.

3. The method of claim 1 wherein at least one sheet comprises a core layer clad with at least one clad layer on at least one side of the core layer.

4. The method of claim 3 wherein the clad layer is bonded to the core layer before homogenizing the stack.

5. The method of claim 1 wherein at least one sheet comprises a core layer clad with at least two clad layers on both sides of the core layer, and wherein the clad layers differ in composition.

6. The method of claim 1 wherein the remaining sheets comprise at least one mobile element.

7. The method of claim 6 wherein the mobile element is present in different concentrations within at least two metal sheets.

8. The method of claim 6 wherein homogenizing the stack equalizes the concentration of the mobile element across all the metal sheets.

9. The method of claim 6 wherein homogenizing the stack comprises heating the stack so that the mobile element diffuses without exceeding the melting point of any of the metal sheets.

10. The method of claim 6 wherein the mobile element comprises at least one of aluminum, tin, zirconium, molybdenum, niobium, chromium, iron, copper, nickel, or vanadium.

11. The method of claim 1 wherein homogenizing the stack comprises heating the stack.

12. The method of claim 1 wherein each metal sheet comprises at least one part region and at least one support region.

13. The method of claim 1 wherein at least one element is present in substantially equal concentrations in at least two metal sheets, and wherein the element does not diffuse in significant quantities during the homogenization of the stack.

14. A system for manufacturing a laminated object, the system comprising: a laminated object manufacturing device configured to stack a plurality of metal sheets, wherein at least one sheet comprises majority titanium and the remaining sheets comprise a distinct elemental composition from the at least one sheet; and a pressor configured to apply at least one of pressure or heat to homogenize the stack, wherein the homogenized stack comprises a titanium alloy of a desired composition.

15. The system of claim 14 wherein the pressor is further configured to bond the metal sheets together before homogenizing the stack.

16. The system of claim 14 wherein at least one of the remaining sheets comprises majority aluminum or aluminum-vanadium.

17. The system of claim 14 wherein at least one sheet comprises a core layer clad with at least one clad layer on at least one side of the core layer.

18. The system of claim 14 wherein the remaining sheets comprise at least one mobile element.

19. The system of claim 14 wherein homogenizing the stack comprises heating the stack.

20. A homogenized titanium alloy part formed via a laminated object manufacturing process, the process comprising: stacking a plurality of metal sheets, wherein at least one sheet comprises majority titanium and the remaining sheets comprise a distinct elemental composition from the at least one sheet; and homogenizing the stack, wherein the homogenized stack comprises a titanium alloy of a desired composition.

21. A cladded metal sheet comprising: a core comprising the balance Ti, between 3.5-4.5 wt.% V, and between 0-6.75 wt.% Al; a clad comprising the balance Al and between 3.5-4.5 wt.% V; and the homogenized cladded metal sheet has an average composition corresponding to the specifications for a grade 5 titanium alloy.

22. The cladded metal sheet of claim 21, with the trace elements in the core and clad compositions comprising at most 0.3 wt.% Fe, at most 0.2 wt.% O, at most 0.08 wt.% C, at most 0.05 wt.% N, at most 0.015 wt.% H, at most 0.005 wt.% Y, and with any other elemental species present at less than 0.05 wt.% and the total of all other elements less than 0.3 wt.%.

23. The cladded metal sheet of claim 21, wherein the clad is at most 9% of the total thickness of the cladded metal sheet.

24. The cladded metal sheet of claim 21, wherein the sheet thickness is between 25 pm and 1000 pm.

25. The cladded metal sheet of claim 21, wherein the core is the first layer of the metal sheet and the clad is the second layer of the metal sheet.

26. The cladded metal sheet of claim 21, wherein the first layer forms a first clad of the metal sheet, a second layer forms the core of the metal sheet, and a third layer forms a second clad of the metal sheet.

27. A cladded metal sheet comprising: a core comprising the balance Ti, between 0-6.0 wt.% Al, between 1.0-4.0 wt.% Sn;a clad comprising the balance Al and between 1.0-4.0 wt.% Sn; and the homogenized cladded metal sheet has an average composition corresponding to the specifications for a grade 6 titanium alloy.

28. The cladded metal sheet of claim 27, with the trace elements in the core and clad comprise at most 0.08 wt.% C, at most 0.5 wt.% Fe, at most 0.02 wt.% H, at most 0.05 wt.% N, at most 0.2 wt.% O, and with any other elemental species present at less than 0.05 wt.% and the total of all other elements less than 0.3 wt.%.

29. A cladded metal sheet comprising: a core comprising the balance Ti and between 1.0-4.0 wt.% V and between 0-3.5 wt.% Al; a clad comprising the balance Al and between 1.0-4.0 wt.% V; and the homogenized cladded metal sheet has an average composition corresponding to the specifications for a grade 9 titanium alloy.

30. The cladded metal sheet of claim 29, with the trace elements in the core and clad are at most 0.08 wt.% C, at most 0.25 wt.% Fe, at most 0.015 wt.% H, at most 0.03 wt.% N, at most0.15 wt.% O, and with any other elemental species present at less than 0.05 wt.% and the total of all other elements less than 0.3 wt.%.

31. A cladded metal sheet comprising: a core comprising the balance Ti, between 0.04-0.1 wt.% Pd, between 1.0-4.0 wt.% V, and between 0-3.5 wt.% Al; a clad comprising the balance Al, between 0-0.08 wt.% Pd, and between 1.0-4.0 wt.% V; and the homogenized cladded metal sheet having an average composition corresponding to the specifications for a grade 18 titanium alloy.

32. The cladded metal sheet of claim 31, with the trace elements in the core and clad are at most 0.08 wt.% C, at most 0.25 wt.% Fe, at most 0.015 wt.% H, at most 0.03 wt.% N, at most0.15 wt.% O, and with any other elemental species present at less than 0.05 wt.% and the total of all other elements less than 0.3 wt.%.

33. A cladded metal sheet comprising: a core comprising the balance Ti, between 1.2-1.8 wt.% Fe, between 0.2-0.3 wt.% O, between 1.0-3.0 wt.% V, and between 0-4.5 wt.% Al; a clad comprising the balance Al, and between 1.0-3.0 wt.% V; and the homogenized cladded metal sheet has an average composition corresponding to the specifications for a grade 38 titanium alloy.

34. The cladded metal sheet of claim 33, with the trace elements in the core and clad are at most 0.08 wt.% C, at most 0.015 wt.% H, at most 0.03 wt.% N, and with any other elemental species present at less than 0.05 wt.% and the total of all other elements less than 0.3 wt.%.

35. A cladded metal sheet comprising: a core comprising the balance Ti, between 0-6.2 wt.% Al, between 5.8-6.2 wt.% Mo, 1.8-2.2 wt.% Sn, and 3.8-4.2 wt.% Zr; a clad comprising the balance Al, between 5.8-6.2 wt.% Mo, 1.8-2.2 wt.% Sn, and 3.8-4.2 wt.% Zr; and the homogenized cladded metal sheet has an average composition corresponding to the specifications for a Ti-6246 titanium alloy.

36. The cladded metal sheet of claim 35, with the trace elements in the core and clad at most 0.1 wt.% C, at most 0.45 wt.% Fe, at most 0.015 wt.% H, at most 0.035 wt.% K, at most 0.25 wt.% Mg, at most 0.04 wt.% N, at most 0.15 wt.% O, at most 0.35 wt.% Si, and with any other elemental species present at less than 0.05 wt.% and the total of all other elements less than 0.3 wt.%.

37. A cladded metal sheet comprising: a core comprising the balance Ti and trace elements; a clad comprising the balance Al and trace elements; and the homogenized cladded metal sheet has an average composition corresponding to the specifications for Ti3 Al.

38. The cladded metal sheet of claim 37, with the trace elements in the core and clad present at less than 0.05 wt.% and the total of all other elements less than 0.5 wt.%.

39. The cladded metal sheet of claim 37, wherein the clad is between 16% and 34% of the total thickness of the cladded metal sheet.

40. The cladded metal sheet of claim 37, wherein the core is the first layer of the metal sheet and the clad is the second layer of the metal sheet.

41. The cladded metal sheet of claim 37, wherein the first layer forms a first clad of the metal sheet, a second layer forms the core of the metal sheet, and a third layer forms a second clad of the metal sheet.

42. A cladded metal sheet comprising: a core comprising the balance Ti and trace elements; a clad comprising the balance Al and trace elements; and the homogenized cladded metal sheet has an average composition corresponding to the specifications for TiAl.

43. The cladded metal sheet of claim 42, with the trace elements in the core and clad present at less than 0.05 wt.% and the total of all other elements less than 0.5 wt.%.

44. The cladded metal sheet of claim 42, wherein the clad is between 44% and 54% of the total thickness of the cladded metal sheet.

45. The cladded metal sheet of claim 42, wherein the core is the first layer of the metal sheet and the clad is the second layer of the metal sheet.

46. The cladded metal sheet of claim 42, wherein the first layer forms a first clad of the metal sheet, a second layer forms the core of the metal sheet, and a third layer forms a second clad of the metal sheet.

47. A cladded metal sheet comprising: a core comprising the balance Ti and trace elements; a clad comprising the balance Al and trace elements; and the homogenized cladded metal sheet has an average composition corresponding to the specifications for TiA12.

48. The cladded metal sheet of claim 47, with the trace elements in the core and clad present at less than 0.05 wt.% and the total of all other elements less than 0.5 wt.%.

49. The cladded metal sheet of claim 47, wherein the clad is between 64% and 66% of the total thickness of the cladded metal sheet.

50. The cladded metal sheet of claim 47, wherein the core is the first layer of the metal sheet and the clad is the second layer of the metal sheet.

51. The cladded metal sheet of claim 47, wherein the first layer forms a first clad of the metal sheet, a second layer forms the core of the metal sheet, and a third layer forms a second clad of the metal sheet.

52. A cladded metal sheet comprising: a core comprising the balance Ti and trace elements; a clad comprising the balance Al and trace elements; and the homogenized cladded metal sheet has an average composition corresponding to the specifications for TiA13.

53. The cladded metal sheet of claim 52, with the trace elements in the core and clad present at less than 0.05 wt.% and the total of all other elements less than 0.5 wt.%.

54. The cladded metal sheet of claim 52, wherein the clad is between 74% and 76% of the total thickness of the cladded metal sheet.

55. The cladded metal sheet of claim 52, wherein the core is the first layer of the metal sheet and the clad is the second layer of the metal sheet.

56. The cladded metal sheet of claim 52, wherein the first layer forms a first clad of the metal sheet, a second layer forms the core of the metal sheet, and a third layer forms a second clad of the metal sheet.

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