WO2020072109A1

WO2020072109A1 - System and method for producing gradient structures in a powder bed, and articles produced therefrom

Info

Publication number: WO2020072109A1
Application number: PCT/US2019/038985
Authority: WO
Inventors: Daniel J. SAUZA; Lynne KARABIN
Original assignee: Arconic Inc.
Priority date: 2018-10-04
Filing date: 2019-06-25
Publication date: 2020-04-09

Abstract

Systems and methods for making gradient structures via a powder bed, and a part produced therefrom are provided. For example, the system comprises a powder bed deposition region, a powder deposition module, and a joining module. The powder bed deposition region is adapted to receive powder and comprises a powder bed deposition surface. The powder deposition module is adapted to dispose a first layer consisting of a first powder in the powder bed deposition region, and to dispose a second layer consisting of a second powder in the powder bed deposition region in contact with the first layer. The first and second powders differ. The joining module is adapted to affix at least a selected region of the second layer to at least a selected region of the first layer.

Description

TITLE

SYSTEM AND METHOD FOR PRODUCING GRADIENT STRUCTURES IN A POWDER BED, AND ARTICLES PRODUCED THEREFROM

CROSS-REFERENCE

[0001] This application claims priority to U.S. Provisional Patent Application No.

62/741,117, which was filed on October 4, 2018. The contents of which is incorporated by reference into this specification.

FIELD OF USE

[0002] The present disclosure relates to a system and method for making gradient structures in a powder bed, and to a part produced using the system and/or method. In certain embodiments, the system and method are applied in an additive manufacturing process.

BACKGROUND

[0003] As used herein,“additive manufacturing” means“a process of joining materials to make objects from 3D model data, usually layer upon layer, as opposed to subtractive manufacturing methodologies”, as defined in ASTM F2792-12a, entitled“Standard

Terminology for Additively Manufacturing Technologies”. Non-limiting examples of additive manufacturing processes useful in producing products from feedstocks include, for example, BJAM (binder jet additive manufacturing), DMLS (direct metal laser sintering), SLM (selective laser melting), SLS (selective laser sintering), and EBM (electron beam melting), among others. Obtaining suitable physical properties in additively manufactured parts presents challenges.

SUMMARY

[0004] According to one aspect of the present disclosure, a powder bed additive

manufacturing system comprises a powder bed deposition region, a powder deposition module, and a joining module. The powder bed deposition region is adapted to receive powder and comprises a powder bed deposition surface. The powder deposition module is adapted to dispose a first layer consisting of a first powder in the powder bed deposition region, and to dispose a second layer consisting of a second powder in the powder bed deposition region in contact with the first layer. The first and second powders differ. The joining module is adapted to affix at least a selected region of the second layer to at least a selected region of the first layer, thereby forming a portion of a part.

[0005] According to another aspect of the present disclosure, a powder bed additive manufacturing method is provided. According to the method, a first layer consisting of a first powder is deposited in a powder bed deposition region of a powder bed additive

manufacturing system. A second layer consisting of a second powder is deposited on at least a region of the first layer. The first powder and the second powder differ. At least a region of the first layer is affixed to the second layer, thereby forming a portion of a part.

[0006] According to yet another aspect of the present disclosure, a part produced by a powder bed additive manufacturing method is provided. The part comprises a first layer and a second layer. The first layer is formed from a first powder, the second layer is formed from a second powder, and the first layer is affixed to the second layer to form a portion of the part. The first powder and the second powder differ.

[0007] It is understood that the inventions disclosed and described in this specification are not limited to the aspects summarized in this Summary. The reader will appreciate the foregoing details, as well as others, upon considering the following detailed description of various non-limiting and non-exhaustive aspects according to this specification.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The features and advantages of the examples, and the manner of attaining them, will become more apparent, and the examples will be better understood, by reference to the following description taken in conjunction with the accompanying drawings, wherein:

[0009] FIG. l is a schematic depiction of a front elevational view of a non-limiting embodiment of an additive manufacturing system according to the present disclosure;

[0010] FIG. 2A is a perspective view of a non-limiting embodiment of an additive manufacturing system according to the present disclosure incorporating a first re-coater and a second re-coater, wherein a first re-coater is shown in a first position; [0011] FIG. 2B is a perspective view of the additive manufacturing system of FIG. 2A wherein the first re-coater is shown in a second position;

[0012] FIG. 2C is a perspective view of the additive manufacturing system of FIG. 2A wherein the first re-coater is shown in a third position;

[0013] FIG. 3 is a perspective view of a non-limiting embodiment of an additive

manufacturing system according to the present disclosure including a re-coater adapted to obtain and dispense two powders;

[0014] FIG. 4 is a cross-sectional view of a non-limiting embodiment of a part produced by a powder bed additive manufacturing process according to the present disclosure; and

[0015] FIG. 5 is a flow chart illustrating a non-limiting embodiment of a powder bed additive manufacturing method according to the present disclosure.

[0016] Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate certain embodiments, in one form, and such exemplifications are not to be construed as limiting the scope of the appended claims in any manner.

DETAILED DESCRIPTION OF NON-LIMITING EMBODIMENTS

[0017] Various embodiments are described and illustrated herein to provide an overall understanding of the structure, function, and use of the disclosed methods, systems, and parts. The various embodiments described and illustrated herein are non-limiting and non- exhaustive. Thus, the invention is not limited by the description of the various non-limiting and non-exhaustive embodiments disclosed herein. Rather, the invention is defined solely by the claims. The features and characteristics illustrated and/or described in connection with various embodiments may be combined with the features and characteristics of other embodiments. Such modifications and variations are intended to be included within the scope of this specification. As such, the claims may be amended to recite any features or characteristics expressly or inherently described in, or otherwise expressly or inherently supported by, this specification. Further, Applicant reserves the right to amend the claims to affirmatively disclaim features or characteristics that may be present in the prior art. The various embodiments disclosed and described in this specification can comprise, consist of, or consist essentially of the features and characteristics as variously described herein.

[0018] Any patent, publication, or other disclosure material identified herein is incorporated herein by reference in its entirety unless otherwise indicated but only to the extent that the incorporated material does not conflict with existing definitions, statements, or other disclosure material expressly set forth in this specification. As such, and to the extent necessary, the express disclosure as set forth in this specification supersedes any conflicting material incorporated by reference herein. Any material, or portion thereof, that is said to be incorporated by reference into this specification, but which conflicts with existing definitions, statements, or other disclosure material set forth herein, is only incorporated to the extent that no conflict arises between that incorporated material and the existing disclosure material. Applicant reserves the right to amend this specification to expressly recite any subject matter, or portion thereof, incorporated by reference herein.

[0019] Any references herein to“various embodiments,”“some embodiments,”“one embodiment,”“an embodiment,” or like phrases, means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases“in various embodiments,”“in some embodiments,”“in one embodiment,”“in an embodiment,” or like phrases, in the

specification do not necessarily refer to the same embodiment. Furthermore, the particular described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Thus, the particular features, structures, or characteristics illustrated or described in connection with one embodiment may be combined, in whole or in part, with the features, structures, or characteristics of one or more other embodiments without limitation. Such modifications and variations are intended to be included within the scope of the present embodiments.

[0020] In this specification, unless otherwise indicated, all numerical parameters are to be understood as being prefaced and modified in all instances by the term“about,” in which the numerical parameters possess the inherent variability characteristic of the underlying measurement techniques used to determine the numerical value of the parameter. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter described herein should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. [0021] Also, any numerical range recited herein includes all sub-ranges subsumed within the recited range. For example, a range of“1 to 10” includes all sub-ranges between (and including) the recited minimum value of 1 and the recited maximum value of 10, that is, having a minimum value equal to or greater than 1 and a maximum value equal to or less than 10. Any maximum numerical limitation recited in this specification is intended to include all lower numerical limitations subsumed therein and any minimum numerical limitation recited in this specification is intended to include all higher numerical limitations subsumed therein. Accordingly, Applicant reserves the right to amend this specification, including the claims, to expressly recite any sub-range subsumed within the ranges expressly recited. All such ranges are inherently described in this specification.

[0022] The grammatical articles“a,”“an,” and“the,” as used herein, are intended to include “at least one” or“one or more,” unless otherwise indicated, even if“at least one” or“one or more” is expressly used in certain instances. Thus, the foregoing grammatical articles are used herein to refer to one or more than one (i.e., to“at least one”) of the particular identified elements. Further, the use of a singular noun includes the plural, and the use of a plural noun includes the singular, unless the context of the usage requires otherwise.

[0023] As used herein,“powder” refers to a material comprising a plurality of particles. Powder may be used in a powder bed in an additive manufacturing system or process to produce a tailored alloy product via additive manufacturing. Powder, as used herein, may comprise a single material or a blend of two or more materials. In certain embodiments, powder can comprise shavings.

[0024] As used herein, a“median particle size” of a powder refers to the diameter at which 50% of the volume of the particles in the powder have a smaller diameter ( e.g Dso). Dio of a powder refers to the diameter at which 10% of the volume of the particles in the powder have a smaller diameter. D90 of a powder refers to the diameter at which 90% of the volume of the particles in the powder have a smaller diameter. As used herein, median particle size, Dio, and D90 are determined in accordance with ASTM standard B822.

[0025] A part made by conventional additive manufacturing techniques is created from a single powder composition. Typically, the resulting additively manufactured part has substantially the same composition throughout the part. The present inventors observed that it may be desirable to have different physical properties at different regions of an additively manufactured part. The present inventors provide herein embodiments directed towards various systems and methods for producing gradient structures in a powder bed and in a resulting part. The gradient structures within the powder bed and the additively

manufactured part produced therefrom can provide different physical properties in different regions of the part such that, for example, the resulting part is configured with tailored properties/performance characteristics at different locations within the part.

[0026] Referring to FIG. 1, a schematic representation of a front elevational view of a non limiting embodiment of an additive manufacturing system 100 according to the present disclosure is provided. The additive manufacturing system 100 can be adapted to conduct at least one additive manufacturing process such as, for example, BJAM, DMLS, SLM, SLS, or EBM. The additive manufacturing system 100 can comprise a powder bed deposition region 102 including a powder bed deposition surface 104, a powder deposition module 106, and a joining module 108. The powder bed deposition region 102 is adapted to receive powder.

[0027] The powder bed deposition region 102 is adapted to receive layers of powder deposited by the powder deposition module 106. In various embodiments, the powder deposition module 106 can comprise at least one of a re-coater, a roller, a brush, and a hopper to facilitate deposition of powder layers. For example, a re-coater can spread powder on the powder bed deposition surface 104 from a reservoir.

[0028] The powder initially is deposited on the powder bed deposition surface 104 and is subsequently deposited on one or more powder layers previously deposited in powder bed 102. In various embodiments, the powder bed deposition surface 104 is adapted to translate vertically to move the powder bed and facilitate deposition of further powder layers in the powder bed deposition region 102. The powder deposition module 106 of system 100 is adapted to deposit layers of at least two different powders in the powder bed deposition region 102. For example, the powder deposition module 106 can deposit a first layer 112 consisting of first powder in the powder bed deposition region 102 and can deposit a second layer 114 consisting of second powder in the powder bed deposition region 102 on at least a portion of the first layer 112. The first powder and second powder can differ in at least one respect. For example, and without limitation, the first powder can comprise a first material and the second powder can comprise a second material that differs from the first material. In various embodiments, the powder deposition module 106 and the system 100 is adapted to deposit a plurality of layers consisting of the first powder in the powder bed deposition region 102, including the first layer 112, and a plurality of layers consisting of the second powder in the powder bed 102, including the second layer 114.

[0029] The number of different powders described and illustrated herein should not be considered limiting as there may be a plurality of different powders deposited as individual layers by the powder deposition module 106. For example, two or more powders, or three or more powders may be selectively deposited as layers in the powder bed deposition region 102 by the powder deposition module 106. For example, the powder deposition module 106 can be adapted to deposit a third layer (not shown) consisting of third powder in the powder bed deposition region 102 in contact with at least a portion of the second layer 114. The first powder, the second powder, and third powder can differ in at least one respect.

[0030] In certain embodiments, each of the different powders ( e.g ., first, second, third) that can be deposited by the system 100 can comprise at least one of metallic particles, polymer particles (e.g., plastic particles), and ceramic particles. In various embodiments, each of the powders are metallic particles selected from at least one of titanium particles, titanium alloy particles, aluminum particles, aluminum alloy particles, nickel particles, nickel alloy particles, iron particles, iron alloy particles, cobalt particles, cobalt alloy particles, copper particles, copper alloy particles, molybdenum particles, molybdenum alloy particles, magnesium particles, magnesium alloy particles, tantalum particles, tantalum alloy particles, tungsten particles, tungsten alloy particles, zinc particles, zinc alloy particles, silver particles, silver alloy particles, chromium particles, chromium alloy particles, tin particles, tin alloy particles, gold particles, gold alloy particles, platinum particles, platinum alloy particles, zirconium particles, and zirconium alloy particles. In certain non-limiting embodiments of system 100, one or more of the powders consists of ceramic particles selected from, for example, oxide particles and non-oxide particles. In various embodiments, at least one of the powders comprises ceramic particles comprising one or more of an oxide, a carbide, a nitride, and a boride.

[0031] In various embodiments, the system and method according to the present disclosure utilizes at least two different powders having different compositions. For example, a first powder may consist of titanium or titanium alloy particles and a second powder may consist of nickel or nickel alloy particles. In various embodiments, the first powder may consist of a first aluminum alloy and the second powder may consist of a second aluminum alloy different than the first. In various other embodiments, the first powder may comprise a blend of titanium and nickel particles in a first ratio, and second powder may comprise a blend of titanium and nickel particles in a second ratio that differs from the first ratio.

[0032] In various embodiments, utilizing different powder compositions can create parts comprising complex metal matrix composite materials. In various embodiments, ceramic particles and/or polymer particles can be used to create features that could improve printing of complex geometries, properties of the part, and/or post-processing of the part. For example, the ceramic particles and/or plastic particles can be deposited at a select location to improve support during printing in order to create complex structures and then later be removed as a sacrificial layer.

[0033] The median particle size of each powder can be adapted for powder bed additive manufacturing. For example, the median particle size of each powder can be adapted to spread a uniform layer of powder across the powder bed deposition surface 104. The median particle size of each powder can be in a range of 1 pm to 300 pm, such as, for example, 1 pm to 300 pm, 5 pm to 300 pm, 5 pm to 100 pm, 10 pm to 180 pm, 100 pm to 180 pm, 10 pm to 100 pm, 105 pm to 180 pm, 20 pm to 50 pm, 60 pm to 90 pm, 50 pm to 100 pm, 10 pm to 50 pm, 10 pm to 80 pm, 10 pm to 20 pm, or 25 pm to 50 pm. In certain embodiments, the powder can include a median particle size not greater than 300 pm, such as, for example, not greater than 290 pm, not greater than 275 pm, not greater than 250 pm, not greater than 225 pm, not greater than 200 pm, not greater than 175 pm, not greater than 150 pm, not greater than 125 pm, not greater than 100 pm, not greater than 90 pm, not greater than 70 pm, not greater than 10 pm, or not greater than 5 pm. In certain embodiments, the powder can include a median particle size of at least 1 pm, such as, for example, at least 5 pm, at least 10 pm, at least 70 pm, at least 90 pm, at least 100 pm, at least 125 pm, at least 150 pm, at least 175 pm, at least 200 pm, at least 225 pm, at least 250 pm, at least 275 pm, or at least 290 pm.

[0034] In various embodiments, each powder can have the same or different median particle size. For example, the first powder can have a first median particle size and the second powder can have a second median particle size different than the first median particle size. In various embodiments, the ratio of the first median particle size to the second median particle size can be from 2: 1 to 20: 1, such as, for example, 2: 1 to 10: 1, 5: 1 to 10: 1, or 6: 1 to 9: 1. In various embodiments, the ratio of the first median particle size to the second median particle size can be from at least 2: 1, such as, for example, at least 5: 1, at least 6:1, at least 9: 1, or at least 10: 1. In various embodiments, the ratio of the first median particle size to the second median particle size can be from no greater than 20: 1, such as, for example, no greater than 10 : 1 , no greater than 9 : 1 , no greater than 6 : 1 , or no greater than 5: 1. In various embodiments, the ratio of the first median particle size to the second median particle size can be 7: 1. In various embodiments, the difference in particle sizes between the powders can enable formation of a denser powder bed in the powder bed deposition region 102 and/or a denser part formed from the powder bed. In various embodiments, the difference in particle sizes between the powders can facilitate separation of the powders that are not incorporated into the part. For example, a mixture of the first and second powders with different median particle sizes can be separated by air classification or sieving. In various embodiments, the D90 of the first powder and the Dio of the second powder can be different by at least 5 pm, such as, for example, at least 10 pm or least 20 microns. The difference in the D90 of the first powder and the Dio of the second powder can facilitate the separation of the powders.

[0035] The median particle size of the powder can be compatible with the thickness of a layer formed form the powder in the powder bed deposition region 102. For example, the layer thickness can be from 1 time to 10 times the median particle size of the powder in the layer, such as, for example, 2 to 8 times the median particle size, or 2 to 4 times the median particle size. In some embodiments, the layer thickness can be 3 times the median particle size. The layer thickness can be, for example, from 100 nm to 3,250 pm, such as, for example, 1 pm to 2,000 pm, 10 pm to 2,000 pm, 10 pm to 1,000 pm, or 50 pm to 300 pm.

In various embodiments, the layer thickness can be 1,000 pm.

[0036] The composition, physical properties, and size of each powder may be chosen based on desired physical properties of the powder for the additive manufacturing process and/or the physical properties of a part or part region formed from the powder. The physical property can comprise, for example, at least one of strength, toughness, crack resistance, printability, corrosion resistance, fatigue, density, ductility, hardness, shear modulus, coefficient of thermal expansion, thermal conductivity, electrical resistivity, creep, and stiffness. In various embodiments, the first powder may be configured with a high strength and a low ductility, and the second powder may be configured with a low strength and high ductility comparative to the first powder. The first powder and second powder may be disposed in different pre-selected regions of the part to create part regions that are stronger than other region and part regions that are more ductile than other regions. [0037] In various embodiments, within each layer 112, 114 the composition of the powder can change. For example, region 1 l2a of layer 112 may comprise a first powder composition that is different than a second powder composition in region 1 l2b of layer 112. In various embodiments, the change in the powder composition from the first powder composition in region 1 l2a to the second powder composition in region 1 l2b can be gradual or steep. For example, a gradual change can be a change of 2 weight percent or less of a component (e.g., first powder, second powder) from the first powder composition to the second powder composition. A steep change can be a change of greater than 2 weight percent of a component from the first powder composition to the second powder composition. In various embodiments, region 1 l2c may comprise a third powder with a composition different from the first and second powders. In various embodiments, the change in the powder composition from the second powder composition in region 1 l2b to the third powder composition in region 1 l2c can be gradual or steep.

[0038] In various embodiments, the powder deposition module 106 can comprise a re-coater, such as, for example, at least one of first re-coater 206a and second re-coater 206b shown in FIGs. 2A-C, or re-coater 306 shown in FIG. 3. The powder deposition module 106 as shown in FIG. 1 can obtain powder from at least two powder reservoirs, such as, a first reservoir 2l0a and a second reservoir 210b as shown in FIGs. 2A-C, and a first reservoir 3 lOa and a second reservoir 310b as shown in FIG. 3. Referring back to FIG. 1, the powder deposition module 106 can move the obtained powder to the powder bed deposition region 102 and deposit the first layer 112 in the powder bed deposition region 102. The powder deposition module 106 can deposit the second layer 114 in the powder bed deposition region 102 on all or one or more regions of the top surface of the first layer 112. In various embodiments, the powder deposition module 106 can repeat the deposition of layers of powder as necessary to create layers of an additively manufactured part.

[0039] At least a selected region 116 of the powder in first layer 112 in the powder bed deposition region 102 can be bound together by the joining module 108. At least a selected region 118 of the powder in second layer 114 in the powder bed deposition region 102 can be affixed together by the joining module 108. Affixing the powder in the selected region 118 can bind or fuse at least the selected region 118 of the second layer 114 to the first layer 112. For example, the selected region 118 in the second layer 114 can be affixed to the selected region 116 in the first layer 112. The bound selected regions 116, 118 can each form a build layer of the additively manufactured part.

[0040] Each powder layer in the part can be individually affixed by the joining module 108 or, alternatively, two or more powder layers can be affixed simultaneously. For example, the powder deposition module 106 can deposit a single layer of powder or a plurality of layers of powder. Next, the joining module 108 can affix a selected region or regions in the powder bed deposition region 102 including an exposed region. In various embodiments, powder in at least a selected region 116 in the first layer 112 in the powder bed deposition region 102 can be bound together by the joining module 108 prior to deposition of the powder forming the second layer 114. In various embodiments, powder in at least the selected region 116 in the first layer 112 and the selected region 118 in the second layer 114 are bound

simultaneously. In various embodiments, the joining module 108 can affix the first layer 112 at least partially to the powder bed deposition surface 104.

[0041] The joining module 108 can be at least one of a binder deposition module and an energy source. The binder deposition module can be adapted to deposit a binder on an exposed layer of powder in the powder bed deposition region 102 to bind the powder in the selected region of the layer together and to powder in an immediately adjacent underlying layer (e.g., of powder, previously affixed powder, powder bed deposition surface). For example, the selected region 118 in the second layer 114 can be affixed to the selected region 116 in the first layer 112 by the binder applied by the joining module 108. In various embodiments, the binder can be a liquid binder.

[0042] In embodiments in which the joining module 108 is an energy source, the source can be adapted to selectively sinter and/or melt powder in a selected region of an exposed layer of powder in the powder bed deposition region 102 to fuse the powder in the selected region of the layer together and to an immediately adjacent underlying layer. For example, the selected region 118 in the second layer 114 can be fused to the selected region 116 in the first layer 112 by the energy source. The energy source can comprise, for example, at least one of a laser module, an electron beam module, and a plasma torch module. A laser module can be adapted to direct a laser beam onto and heat at least a selected region of an exposed layer of powder in the powder bed deposition region 102 to fuse powder in the selected region together and to an immediately adjacent underlying layer. An electron beam module can be adapted to direct an electron beam onto and heat at least a selected region of an exposed layer of powder in the powder bed reposition region 102 to fuse powder in the selected region together and to an immediately adjacent underlying layer. A plasma torch module can be adapted to direct plasma onto and heat at least a selected region of an exposed layer of powder in the powder bed deposition region 102 to fuse the powder in the selected region together and to an immediately adjacent underlying layer. For example, the selected region 118 in the second layer 114 can be fused to the selected region 116 in the first layer 112 by the laser module, electron beam module, or plasma torch module. In various embodiments, the source can be adapted to selectively sinter and/or melt powder in a selected region of an exposed layer of powder in the powder bed deposition region 102 to fuse the powder in the selected region of the layer together and to at least two layer underlying layers including an immediately adjacent underlying layer and an additional layer of powder underlying the immediately adjacent underlying layer.

[0043] The sequence of depositing a layer or layers of powder and affixing a selected region or regions of the layer or layers can be repeated as needed to produce layers of the additively manufactured part, which includes powder particles bound/fused together.

[0044] FIGs. 2A-C illustrates a non-limiting embodiment of an additive manufacturing system 200 having a powder bed deposition region 202 including a powder deposition surface, and at least two re-coaters including a first re-coater 206a and a second re-coater 206b. The first re-coater 206a can be adapted to dispose layers of a first powder in the powder bed deposition region 202 obtained from a first powder reservoir 2l0a. The first re- coater 206a can contact exposed powder in the first powder reservoir 2l0a and push or otherwise facilitate movement of the first powder to the powder bed deposition region 202. For example, the first re-coater 206a can move laterally from a first position illustrated in FIG. 2A to a second position illustrated in FIG. 2B so that the first re-coater 206a pushes a mass of the first powder laterally out of the first powder reservoir 2l0a and deposits a layer of the first powder in the powder bed deposition region 202. In various embodiments, the first powder is deposited in a layer on the powder deposition surface of the powder bed deposition region 202, or is deposited on an exposed surface of a previously deposited layer of powder in the powder bed deposition region 202.

[0045] The first re-coater 206a can move laterally from the second position illustrated in FIG. 2B to a third position illustrated in FIG. 2C. The lateral movement of the first re-coater 206a to the third position can complete deposition of the mass of the first powder pushed from the first reservoir 2l0a into a layer in the powder bed deposition region 202. In certain embodiments, excess first powder pushed from the first powder reservoir 2l0a by the lateral movement of the first re-coater 206a shown in FIGs. 2A-C may not be deposited in the layer and can be removed from the powder bed deposition region 202. For example, the excess portion of the first powder can be pushed to and deposited in the first recycle compartment 220a by further movement of the first re-coater 206a. In various embodiments, the excess portion of the first powder can be returned to the first powder reservoir 2l0a from the first recycle compartment 220a.

[0046] The second re-coater 206b can be adapted to dispose a layer or layers of powder in the powder bed 202 from a second reservoir 210b. The second re-coater 206b can obtain second powder from the second reservoir 210b. The second re-coater 206b can contact exposed powder in the second reservoir 210b and push or otherwise facilitate movement of the second powder to the powder bed 202. For example, the second re-coater 206b can move laterally so that the second re-coater 206b pushes a mass of the second powder laterally out of the second reservoir 210b and can deposit a layer of the second powder along an exposed surface of an immediately underlying powder layer, such as a layer of the first powder deposited by the first re-coater 206a.

[0047] The second re-coater 206b can move laterally to spread the mass of the second powder obtained from the second reservoir 210b into a layer in the powder bed deposition region 202. In certain embodiments, excess second powder pushed from the second reservoir 210b by the lateral movement of the second re-coater 206b may not be deposited in the layer and can be removed from the powder bed deposition region 202. For example, the excess portion of the second powder can be deposited in a second recycle compartment 220b. In various embodiments, the excess portion of the second powder can be returned to the second reservoir 210b from the second recycle compartment 220b.

[0048] In various embodiments, the additive manufacturing system 200 can comprise a joining module (not shown) such as, for examplejoining module 108 shown in FIG. 1. For example, the joining module can affix ( e.g bind or fuse) powder in a selected region or regions of the layer or layers deposited by the first re-coater 206a and/or the second re-coater 206b in the powder bed deposition region 202. The sequence of depositing a layer or layers of powder and binding or fusing powder in the selected region or regions of the layer or layers can be repeated as needed to produce all or portions of the additively manufactured part.

[0049] Referring to FIG. 3, a perspective view of a non-limiting embodiment of an additive manufacturing system 300 including a re-coater 306 configured to dispense two or more different powders is provided. The re-coater 306 can communicate with a dispenser 322, which in turn can communicate with two or more powder reservoirs such as, for example, first powder reservoir 3 lOa and second powder reservoir 3 lOb. Each reservoir 3 lOa, 3 lOb can be adapted to store a powder. For example, first powder reservoir 3 lOa can contain a first powder, and second powder reservoir 3 lOb can contain a second powder, which may differ in at least one respect form the first powder.

[0050] The powder reservoirs 3 lOa, 3 lOb can deposit powder into the dispenser 322. The dispenser 322 can be adapted to selectively receive the first powder from the first powder reservoir 3 lOa and/or the second powder from the second powder reservoir 3 lOb. In other words, the dispenser 322 can be adapted to receive powder from one powder reservoir at a time or from two or more powder reservoirs at one time. In various embodiments, the dispenser 322 can receive the first powder from first powder reservoir 3 lOa and introduce the first powder to the re-coater 306. The dispenser 322 can receive second powder from the second powder reservoir 3 lOb and introduce the second powder to the re-coater 306. In various embodiments, the dispenser 322 can receive first powder from the first powder reservoir 3 lOa and also receive second powder from the second powder reservoir 3 lOb, either simultaneously or consecutively, and blend the first and second powders in a preselected weight or volume ratio to create a blended powder. The blended powder can then be introduced to the re-coater 306 and disposed as a layer in the powder bed deposition region 202. In various embodiments, two or more different powders can be blended in desired ratios prior to adding the resulting powder blend to the dispenser 322.

[0051] In various embodiments, the dispenser 322 can receive a blend of the first powder and the second powder that varies over time. For example, the weight or volume ratio of the first powder to the second powder in a blend of the two powders at the time the powder blend initially is passed to the re-coater 306 from the powder dispenser 322 can be different from the ratio of the first powder to the second powder in the powder blend passed to the re-coater 306 from the powder dispenser after a period of time. The amount and rate of change in the ratio of first to second powders over time can be selected as desired to produce powder layers with the re-coater 306 having the desired blend ratio of powders in various regions of the layer. Thus, for example, the dispenser 322 can dynamically adjust the ratio of two or more powders in a powder blend provided from the dispenser 322 to the re-coater 306.

[0052] In various embodiments, the dispenser 322 may be stationary and have an opening adapted to dispense powder uniformly in a line extending from a first side 324 of the re- coater 306 to a second side 326 of the re-coater 306 to deposit powder 328. In various embodiments, the dispenser 322 can move from the first side 324 of the re-coater 306 to the second side 326 of the re-coater 306 and dispense powder at a uniform rate as the dispenser moves to create a line of powder 328. The dispenser 322 may move from the second side 326 of the re-coater 306 to the first side 324 of the re-coater 306 and dispense powder at a uniform rate as the dispenser moves to create a line of powder 328.

[0053] The re-coater 306 can be in communication with and receive powders from the dispenser 322 and can be adapted to dispose a layer or layers of powder in the powder bed deposition region 302. The re-coater 306 and dispenser 322 can be adapted to dispose a layer or layers consisting of the first powder in the powder bed deposition region 302 from the first powder reservoir 3 lOa and a layer or layers consisting of the second powder in the powder bed deposition region 302 from the second powder reservoir 3 lOb. In various embodiments, the dispenser 322 can be adapted to dispose layers consisting of a blended powder including at least the first powder and the second powder in the powder bed deposition region 302. In various embodiments, the powder bed deposition region 302 comprises a powder deposition surface (not shown) such as, for example, powder bed deposition surface 104 as shown in FIG. 1, which can translate vertically downward to increase the volume of the powder bed deposition region 302 to facilitate deposition of a new powder layer.

[0054] The re-coater 306 can receive powder from the dispenser 322 and can facilitate movement of the powder to the powder bed deposition region 302. For example, the re- coater 306 can move laterally as powder is introduced to the re-coater 306 from the dispenser 322 so that the re-coater 306 can deposit the powder as a layer in the powder bed deposition region 302. The layer may be deposited on the powder deposition surface, if exposed, or on the exposed surface of a previously deposited powder layer. The re-coater 306 can move laterally to complete deposition of a mass of powder from the dispenser 322 in a layer in the powder bed deposition region 302. In certain embodiments, excess powder from the dispenser 322 may not be deposited in the layer and can be removed from the powder bed deposition region 302. For example, the excess powder can be moved to and deposited in the recycle compartment 320 disposed at one end of the powder bed deposition region 302, which can be adapted to receive and store the excess powder ( e.g ., excess first powder, excess second powder, or excess blended powder) from the powder bed deposition region 302.

[0055] In various embodiments, the additive manufacturing system 300 can comprise a joining module (not shown in Fig. 3) such as, for examplejoining module 108 as shown in FIG. 1. The joining module can affix (e.g., bind or fuse) powder all or a selected region or regions of a powder layer or powder layers deposited by the re-coater 306. The sequence of depositing a layer or layers of powder and binding or fusing powder in the selected region or regions of the layer or layers can be repeated as needed to produce all or a portion of the additively manufactured part.

[0056] Excess blended powders and other powders collected in the first recycle compartment 220a and second recycle compartment 220b as shown in FIG. 2, or in the recycle

compartment 320 as shown in FIG. 3, can be separated into the constituent powders collected in those recycle compartments. For example, the individual powders making up a collected blended powder may have different physical properties and can be sorted based on one or more of those differing physical properties. In various embodiments, the physical properties can include median particle size, a magnetic property, bulk density, and solubility. For example, the median particle size of the first powder can differ from a median particle size of the second powder, and the additive manufacturing system 100, 200, 300 according to the present disclosure may further comprise a sieve adapted to separate the first powder and the second powder from powder collected in the corresponding recycle container.

[0057] In various embodiments, the first powder can be magnetic and the second powder can be non-magnetic and the additive manufacturing system 100, 200, 300 according to the present disclosure may further comprise a magnetic apparatus adapted to separate the first powder from the second powder. In other embodiments, a bulk density of the first powder can differ from a bulk density of the second powder and the additive manufacturing system 100, 200, 300 according to the present disclosure may further comprise an apparatus that sorts on the basis of density such as, for example, an air classifier. [0058] Referring to FIG. 4, a cross-sectional view of a non-limiting embodiment of a part 400 produced by a powder bed additive manufacturing process or system according to the present disclosure is shown. The part 400 can include a plurality of layers such as layers 402a-n. The layers 402a-n can be affixed to one another to form a monolithic structure in the desired part shape. Each layer 402a-n can be formed from powder which can be the same or differ from powder used to form another of the layers 402a-n. In various embodiments, the powder used to form any of the layers 400a-n can be a blended powder. The depicted cross- section of the part 400 can comprise, for example, sides 400a, 400b, 400c, and 400d. In certain embodiments, the powder used to form a layer 400a-n can have a composition that varies as one traverses the layer from a first side 400a of the part 400 to a second side 400b of the part 400. Thus, the individual layers of the part 400 can comprise a gradient composition as one moves along a layer 402a-402n from a first side 400a to a second side 400b of the particular layer. The composition of individual layers also can differ from one layer to another and, therefore, a gradient composition also can be present as one moves from layer to layer from the third side 400c to the fourth side 400d of the part 400. Accordingly, the part 400 can comprise various physical properties in different regions of the part 400, and the composition of individual layers and regions of individual layers can be varied by suitable selection of individual powders or powder blends to produce gradients of properties as one moves from location to location in the part 400.

[0059] In one example, a“layer Xi” and a“layer X₂” refer to any two adjacent layers selected from layers 400a-n in FIG. 4. Layer Xi can be formed from a first powder and layer X2 can be formed from a second powder that differs from the first powder in at least one respect. For example, the first powder can have a different elemental composition than the second powder. The layer X2 can be affixed to the layer Xi. In various embodiments, layer X2 can be fused to layer Xi using an energy source. In other embodiments, layer X2 can be affixed to layer Xi by a binder such as, for example a binder conventionally used in BJAM. Thus, the adjacent layers Xi, X2 can have different compositions.

[0060] In various embodiments, layer 402a can consist of a composition formed from the first powder, layer 402n can consist of a composition formed from a second powder, and intervening layers 402b-m can be formed from a blended powder composed of the first powder and second powder. Upon traversal of the part 400 from layer 402a to layer 402n, the ratio of the first powder to the second powder used to form the respective layer may decrease to form a composition gradient across the part 400 from side 400c to side 400d. In some embodiments, layers 402a-f can consist a composition formed from a first powder and layers 402g-n can consist of a composition formed from a second powder such that there is an abrupt change in the material composition of the part 400 at the interface of layers 402f and 402g. In various embodiments, layers 402a-c can comprise a composition formed from a first powder, layers 402d-f can comprise a composition formed from a second powder, and layers 402g-n can comprise a composition formed from a third powder, and the first, second, and third powders differ. The described compositions and arrangements of the layers 402a-n herein is for purposes of illustration only and should not be considered limiting.

[0061] FIG. 5 presents a flow chart 500 illustrating a non-limiting embodiment of a process for the producing a part by powder bed additive manufacturing according to the present disclosure. As shown, a first layer consisting of a first powder can be deposited on a powder deposition surface in a powder bed deposition region of a powder bed additive manufacturing apparatus 502. In various embodiments, after depositing the first layer, excess first powder can be moved to and deposited in a first recycle compartment 504. Powder in all or a region of the first layer can be affixed to the powder deposition surface and/or affixed together 506.

[0062] A powder is selected or preselected for a subsequent layer 508. In various

embodiments, for example, the powder may include two or more powders blended in a preselected weight or volume ratio to form a blended powder. The subsequent layer consisting of the selected and/or preselected powder can be deposited on at least a region of the first layer 510. The first powder and the powder blend can differ in one or more respects. In various embodiments, after depositing the subsequent layer on the first layer, an excess amount of the powder used to form the subsequent layer can be moved to and deposited in a recycle compartment that is the same as or differ from the first recycle compartment 512. At least a region of the subsequent layer is affixed ( e.g ., using a binder or by applying energy) to the underlying layer 514. Steps 508 to 514 may be repeated as necessary to build a part 516. In various embodiments, steps 508 to 512 can be repeated as necessary to build up multiple layers of powder prior to step 514. For example, at step 514, multiple layers can be affixed (e.g., using a binder or by applying energy) simultaneously. In various embodiments, the powder in the first recycle compartment, a second recycle compartment, and/or other recycle compartments can be separated into two or more separate powders utilizing a physical property of the powder in the particular recycle compartment 518.

[0063] Additive Manufacturing [0064] The parts described herein may be manufactured via any appropriate additive manufacturing technique described in ASTM F2792~12a. In one embodiment, an additive manufacturing process includes depositing successive layers of powder and then selectively melting and/or sintering the powder to create, layer-by-layer, a part. In one embodiment, a powder bed is used to create a part such as, for example, a tailored alloy part and/or a unique structure unachievable through traditional manufacturing techniques (e.g., without excessive post-processing machining).

[0065] Non-limiting examples of additive manufacturing processes useful in producing parts from feedstocks include, for example, BJAM, DMLS, SLM, SLS, and EBM, among others. In one embodiment, an additive manufacturing process uses an EOSINT M 280 Direct Metal Laser Sintering (DMLS) additive manufacturing system, or comparable system, available from EOS GmbH (Robert-Stirling-Ring 1, 82152 Krailling/Munich, Germany). Additive manufacturing techniques (e.g., when utilizing metallic feedstocks) may facilitate the selective heating of powder above the liquidus temperature of the powder, thereby forming a molten pool followed by rapid solidification of the molten pool.

[0066] Any suitable feedstocks may be used, including powder, a wire, a sheet, and combinations thereof. In various embodiments, the feedstock may be, for example, metallic feedstocks (e.g., with additives to promote various properties such as, for example, grain refiners and/or ceramic materials), polymeric feedstocks (e.g., plastic feedstocks), and ceramic feedstocks. In certain embodiments, the wire can comprise a ribbon and/or a tube. The metallic feedstocks can be at least one of titanium, titanium alloy, aluminum, aluminum alloy, nickel, nickel alloy, iron, iron alloy, cobalt, cobalt alloy, copper, copper alloy, molybdenum, molybdenum alloy, magnesium, magnesium alloy, tantalum, tantalum alloy, tungsten, tungsten alloy, zinc, zinc alloy, silver, silver alloy, chromium, chromium alloy, tin, tin alloy, gold, gold alloy, platinum, platinum alloy, zirconium, and zirconium alloy. In certain embodiments, reagent-based feedstock materials which form polymeric parts can be used as feedstock.

[0067] As used herein,“aluminum alloy” means a metal alloy having aluminum as the predominant alloying element. Similar definitions apply to the other corresponding alloys referenced herein (e.g., titanium alloy means a titanium alloy having titanium as the predominant alloying element). [0068] In one approach, an additive manufacturing process comprises (a) dispersing a feedstock (e.g., powder in a powder bed), (b) selectively heating a portion of the powder (e.g., via an energy source) to a temperature above the liquidus temperature of the powder,

(c) forming a molten pool and (d) cooling the molten pool at a cooling rate of at least l000°C per second, such as, for example, at least l0,000°C per second, at least l00,000°C per second, or at least l,000,000°C per second. Steps (a)-(d) may be repeated as necessary until the additively manufactured part is completed.

[0069] In another approach, an additive manufacturing process comprises (a) dispersing a feedstock (e.g., metallic powder) in a deposition region, (b) selectively binder jetting the feedstock, and (c) repeating steps (a)-(b), thereby producing a final additively manufactured part (e.g., including optionally heating to burn off binder and form a green form, followed by sintering to form the additively manufactured part).

[0070] In another approach, electron beam or plasma arc techniques are utilized to produce at least a portion of the additively manufactured part. Electron beam techniques may facilitate production of larger parts than readily produced via laser additive manufacturing techniques. An illustrative example provides feeding a wire to the wire feeder portion of an electron beam gun. The wire may comprise a metallic feedstock. The electron beam heats the wire above the liquidus point of the metallic feedstock and deposits the molten pool in a deposition region. Thereafter, rapid solidification of the molten pool to form the deposited material occurs.

[0071] Production and Processing

[0072] In some embodiments, the additively manufactured part may be subject to any appropriate dissolving (e.g., includes homogenization), working and/or precipitation hardening steps. If employed, the dissolving and/or the working steps may be conducted on an intermediate form of the additively manufactured part and/or may be conducted on a final form of the additively manufactured part. If employed, the precipitation hardening step is generally conducted relative to the final form of the additively manufactured part.

[0073] After or during production, an additively manufactured part may be deformed (e.g., by one or more of rolling, extruding, forging, stretching, compressing). The final deformed product may realize, for instance, improved properties due to the tailored regions and thermo- mechanical processing of the final deformed part. Thus, in some embodiments, the final part is a wrought part, the word“wrought” referring to the working (hot working and/or cold working) of the additively manufactured part, wherein the working occurs relative to an intermediate and/or final form of the additively manufactured part. In other approaches, the final part is a non-wrought product, i.e., is not worked during or after the additive

manufacturing process. In these non-wrought product embodiments, any appropriate number of dissolving and precipitating steps may still be utilized.

[0074] Product Applications

[0075] The resulting additively manufactured parts (e.g., part 400) made in accordance with the systems and methods described herein may be used in a variety of product applications such as, commercial end-uses in industrial applications, in consumer applications (e.g., consumer electronics and/or appliances), or in other areas. For example, the additively manufactured parts can be utilized in at least one of the aerospace field (e.g., aerospace component), automotive field (e.g., automotive component), transportation field (e.g., transportation component), or building and construction field (e.g., building component or construction component). In certain embodiments, the additively manufactured parts can be configured as at least one of an aerospace component, an automotive component, a transportation component, and a building and construction component.

[0076] In one embodiment, an additively manufactured part can be utilized in an elevated temperature application, such as in an aerospace or automotive vehicle. In one embodiment, an additively manufactured part can be utilized as an engine component in an aerospace vehicle (e.g., in the form of a blade, such as a compressor blade incorporated into the engine). In another embodiment, an additively manufactured part can be used as a heat exchanger for the engine of the aerospace vehicle. The aerospace vehicle including the engine component / heat exchanger may subsequently be operated. In one embodiment, an additively

manufactured part can be an automotive engine component. The automotive vehicle including an automotive component (e.g., engine component) may subsequently be operated. For instance, the additively manufactured part may be used as a turbo charger component (e.g., a compressor wheel of a turbo charger, where elevated temperatures may be realized due to recycling engine exhaust back through the turbo charger), and the automotive vehicle including the turbo charger component may be operated. In another embodiment, an additively manufactured part may be used as a blade in a land based (stationary) turbine for electrical power generation, and the land-based turbine included the additively manufactured part may be operated to facilitate electrical power generation. In some embodiments, an additively manufactured part can be utilized in defense applications, such as in body armor, and armed vehicles (e.g., armor plating). In other embodiments, the additively manufactured part can be utilized in consumer electronic applications, such as in consumer electronics, such as, laptop computer cases, battery cases, cell phones, cameras, mobile music players, handheld devices, computers, televisions, microwaves, cookware, washers/dryers, refrigerators, and sporting goods, among others.

[0077] In another aspect, an additively manufactured part can be utilized in a structural application, such as, for example, an aerospace structural application and an automotive structural application. For instance, the additively manufactured part may be formed into various aerospace structural components, including floor beams, seat rails, fuselage framing, bulkheads, spars, ribs, longerons, and brackets, among others. In another embodiment, the additively manufactured part can be utilized in an automotive structural application. For instance, the additively manufactured part can be formed into various automotive structural components including nodes of space frames, shock towers, and subframes, among others. In one embodiment, the additively manufactured part can be a body -in-white automotive product.

[0078] In another aspect, the additively manufactured part can be utilized in an industrial engineering application. For instance, the additively manufactured part or products may be formed into various industrial engineering products, such as tread-plate, tool boxes, bolting decks, bridge decks, and ramps, among others.

[0079] Various aspects of the invention according to the present disclosure include, but are not limited to, the aspects listed in the following numbered clauses.

1. A powder bed additive manufacturing system comprising:

a powder bed deposition region adapted to receive powder and comprising a powder bed deposition surface;

a powder deposition module adapted to dispose a first layer consisting of a first powder in the powder bed deposition region, and to dispose a second layer consisting of a second powder in the powder bed deposition region in contact with the first layer, wherein the first and second powders differ; and a joining module adapted to affix at least a selected region of the second layer of to at least a selected region of the first layer. The system of clause 1, wherein the powder deposition module is adapted to dispose a third layer consisting of third powder in the powder bed deposition region in contact with the second layer, wherein the first, second, and third powders differ. The system of any one of clauses 1 to 2, wherein the powder deposition module is adapted to deposit:

a plurality of layers consisting of the first powder in the powder bed deposition region, including the first layer; and

a plurality of layers consisting of the second powder in the powder bed deposition region, including the second layer. The system any one of clauses 1 to 3, further comprising:

a first recycle compartment adapted to receive excess first powder from the powder bed deposition region; and

a second recycle compartment adapted to receive excess second powder from the powder bed deposition region. The system any one of clauses 1 to 3, further comprising:

a recycle compartment adapted to receive excess first powder and excess second powder from the powder bed deposition region. The system of any one of clauses 1 to 5, further comprising: a first powder reservoir adapted to hold the first powder and communicating with the powder deposition module; and

a second reservoir adapted to hold the second powder and communicating with the powder deposition module. The system of any one of clauses 1 to 6, wherein the powder deposition module comprises: a first re-coater adapted to dispose layers consisting of the first powder in the powder bed deposition region from the first reservoir. The system of clause 7, wherein the powder deposition module comprises: a second re-coater adapted to dispose layers consisting of the second powder in the powder bed deposition region from the second reservoir. The system of clause 6, wherein the powder deposition module comprises:

a dispenser communicating with the first reservoir and second reservoir, the dispenser adapted to selectively receive the first powder from the first reservoir or the second powder from the second reservoir;

wherein the dispenser is further adapted to dispose layers consisting of the first powder in the powder bed deposition region from the first reservoir, and layers consisting of the second powder in the powder bed deposition region from the second reservoir. The system of clause 6, wherein the powder deposition module comprises:

a dispenser communicating with the first reservoir and the second reservoir, the dispenser adapted to blend the first powder from the first reservoir with the second powder from the second reservoir in a preselected ratio to form blended powder; and wherein the dispenser is adapted to dispose layers consisting of the blended powder in the powder bed deposition region. The system of any one of clauses 1 to 10, wherein the first powder comprises at least one of metallic particles, polymer particles, and ceramic particles. The system of clause 11, wherein the second powder comprises at least one of metallic particles, polymer particles, and ceramic particles. The system of any one of clauses 1 to 12, wherein the first powder comprises at least one of titanium particles, titanium alloy particles, aluminum particles, aluminum alloy particles, nickel particles, nickel alloy particles, iron particles, iron alloy particles, cobalt particles, cobalt alloy particles, copper particles, copper alloy particles, molybdenum particles, molybdenum alloy particles, magnesium particles, magnesium alloy particles, tantalum particles, tantalum alloy particles, tungsten particles, tungsten alloy particles, zinc particles, zinc alloy particles, silver particles, silver alloy particles, chromium particles, chromium alloy particles, tin particles, tin alloy particles, gold particles, gold alloy particles, platinum particles, platinum alloy particles, zirconium particles, and zirconium alloy particles. The system of clause 13, wherein the second powder comprises at least one of titanium particles, titanium alloy particles, aluminum particles, aluminum alloy particles, nickel particles, nickel alloy particles, iron particles, iron alloy particles, cobalt particles, cobalt alloy particles, copper particles, copper alloy particles, molybdenum particles, molybdenum alloy particles, magnesium particles, magnesium alloy particles, tantalum particles, tantalum alloy particles, tungsten particles, and tungsten alloy particles. The system of any one of clauses 1 to 15, wherein the first powder has a first median particle size in a range of 1 pm to 300 pm. The system of clause 15, wherein the second powder has a second median particle size in a range of 1 pm to 300 pm. The system of clause 16, wherein the first median particle size differs from the second median particle size. The system of clause 17, wherein a ratio of the first median particle size to the second median particle size is in a range of 2: 1 to 20: 1. The system of any one of clauses 1 to 18, wherein:

a median particle size of the first powder differs from a median particle size of the second powder; and

the system further comprises a sieve adapted to sort the first powder and the second powder from powder in the recycle compartment. The system of any one of clauses 1 to 19, wherein the first powder is magnetic and the second powder is non-magnetic. The system of clause 20, further comprising: a magnetic apparatus adapted to separate the first powder from the second powder. The system of any one of clauses 1 to 21, wherein a bulk density of the first powder differs from a bulk density of the second powder. The system of any one of clauses 1 to 22, wherein the joining module comprises a binder deposition module adapted to deposit a binder on at least a selected region of an exposed layer of powder in the powder bed deposition region, binding the selected region of the layer of powder to an immediately adjacent underlying layer. The system of any one of clauses 1 to 23, wherein the joining module comprises a laser module adapted to direct a laser beam onto and heat at least a selected region of an exposed layer of powder in the powder bed deposition region, fusing the selected region of the exposed layer of powder to an immediately adjacent underlying layer. The system of any one of clauses 1 to 24, wherein the joining module comprises an electron beam module adapted to direct an electron beam onto and heat at least a selected region of an exposed layer of powder in the powder bed deposition region, fusing the selected region of the exposed layer of powder to an immediately adjacent underlying layer. The system of any one of clauses 1 to 25, wherein the powder bed additive manufacturing system is adapted to conduct at least one additive manufacturing process selected from binder jet additive manufacturing, electron beam melting, direct metal laser sintering, selective laser melting, and selective laser sintering. An additive manufacturing method comprising:

depositing a first layer consisting of a first powder on a powder bed deposition surface of a powder bed deposition region; depositing a second layer consisting of a second powder on at least a region of the first layer, wherein the first powder and the second powder differ; and

affixing at least a region of the first layer to the second layer;

wherein the additive manufacturing method is a powder bed additive manufacturing method. The method of clause 27, further comprising depositing a third layer consisting of third powder in the powder bed deposition region in contact with the second layer, wherein the first powder, the second powder, and the third powder differ. The method of any one of clauses 27 to 28, further comprising:

depositing a plurality of layers consisting of the first powder in the powder bed deposition region, including the first layer; and

depositing a plurality of layers consisting of the second powder in the powder bed deposition region, including the second layer. The method of any one of clauses 27 to 29, further comprising:

receiving excess first powder from the powder bed deposition region in a first recycle compartment; and

receiving excess second powder from the powder bed deposition region in a second recycle compartment. The method of any one of clauses 27 to 30, further comprising:

receiving excess first powder and excess second powder from the powder bed deposition region in a recycle compartment. The method of any one of clauses 27 to 31, further comprising maintaining the first powder separate from the second powder prior to depositing the first powder and the second powder in the powder deposition region. The method of any one of clauses 27 to 32, wherein the first powder is maintained in a first powder reservoir and the second powder is maintained in a second powder reservoir prior to depositing the first powder and the second powder in the powder deposition region. The method of any one of clauses 27 to 33, further comprising:

depositing layers consisting of the first powder in the powder deposition region from a first re-coater; and

depositing layers consisting of the second powder in the powder bed deposition region from a second re-coater, wherein the first re-coater and the second re-coater are not the same re-coater. The method of any one of clauses 27 to 34, further comprising:

depositing layers consisting of the first powder in the powder deposition region from a re-coater; and

depositing layers consisting of the second powder in the powder bed deposition region from the re-coater. The method of any one of clauses 27 to 35, further comprising blending the first powder with the second powder in a preselected ratio to form blended powder and depositing layers of the blended powder in the powder bed deposition region. The method of any one of clauses 27 to 36, wherein the first powder comprises at least one of metallic particles, polymer particles, and ceramic particles. The method of clause 37, wherein the second powder comprises at least one of metallic particles, polymer particles, and ceramic particles. The method of any one of clauses 27 to 38, wherein the first powder comprises at least one of titanium particles, titanium alloy particles, aluminum particles, aluminum alloy particles, nickel particles, nickel alloy particles, iron particles, iron alloy particles, cobalt particles, cobalt alloy particles, copper particles, copper alloy particles, molybdenum particles, molybdenum alloy particles, magnesium particles, magnesium alloy particles, tantalum particles, tantalum alloy particles, tungsten particles, tungsten alloy particles, zinc particles, zinc alloy particles, silver particles, silver alloy particles, chromium particles, chromium alloy particles, tin particles, tin alloy particles, gold particles, gold alloy particles, platinum particles, platinum alloy particles, zirconium particles, and zirconium alloy particles. The method of clause 39, wherein the second powder comprises at least one of titanium particles, titanium alloy particles, aluminum particles, aluminum alloy particles, nickel particles, nickel alloy particles, iron particles, iron alloy particles, cobalt particles, cobalt alloy particles, copper particles, copper alloy particles, molybdenum particles, molybdenum alloy particles, magnesium particles, magnesium alloy particles, tantalum particles, tantalum alloy particles, tungsten particles, tungsten alloy particles, zinc particles, zinc alloy particles, silver particles, silver alloy particles, chromium particles, chromium alloy particles, tin particles, tin alloy particles, gold particles, gold alloy particles, platinum particles, platinum alloy particles, zirconium particles, and zirconium alloy particles. The method of any one of clauses 27 to 40, wherein the first powder has a first median particle size in a range of 1 pm to 300 pm. The method of clause 41, wherein the second powder has a second median particle size in a range of 1 pm to 300 pm. The method of clause 42, wherein the first median particle size and the second median particle sizes differ. The method of clause 43, wherein a ratio of the first median particle size to the second median particle size is in a range of 2: 1 to 20: 1. The method of any one of clauses 27 to 44, wherein:

the method further comprises receiving excess first powder and excess second powder from the powder bed region and separating the first powder from the second powder utilizing a sieve. The method of any one of clauses 27 to 45, wherein the first powder is magnetic and the second powder is non-magnetic. The method of clause 46, further comprising: receiving excess first powder and excess second powder from the powder bed region and separating the first powder from the second powder utilizing a magnetic apparatus. The method of any one of clauses 27 to 47, wherein a bulk density of the first powder differs from a bulk density of the second powder. The method of any one of clauses 27 to 48, further comprising:

receiving excess first powder and excess second powder from the powder bed region and separating the first powder from the second powder utilizing a density sorter. The method of any one of clauses 27 to 49, further comprising depositing a binder on at least a selected region of an exposed layer of powder in the powder bed deposition region, binding the selected region of the exposed layer of powder to an immediately adjacent underlying layer. The method of any one of clauses 27 to 50, further comprising contacting at least a selected region of an exposed layer of powder with at least one of a laser beam and an electron beam thereby heating and fusing the selected region of the exposed layer of powder to an immediately adjacent underlying layer. The method of any one of clauses 27 to 51, wherein the method comprises a technique selected from binder jet additive manufacturing, laser powder bed fusion, electron beam melting, direct metal laser sintering, selective laser melting, and selective laser sintering. The method of any one of clauses 27 to 52, further comprising affixing at least a region of the first layer to the powder bed deposition surface. A part comprising: a first layer formed from a first powder; and

a second layer formed from a second powder affixed to the first layer, wherein the first and second powders differ, and wherein the part is produced by a powder bed additive manufacturing process. The part of clause 54, further comprising:

a plurality of layers formed from the first powder, including the first layer; and a plurality of layers formed from the second powder, including the second layer. The part of any one of clauses 54 to 55, further comprising:

a third layer comprising a third powder affixed to the second layer;

wherein the first powder, the second powder, and the third powder differ. The part of any one of clauses 54 to 56, wherein the second layer has been affixed to the first layer using an energy source. The part of any one of clauses 54 to 57, wherein the second layer has been affixed to the first layer by a binder. The part of any one of clauses 54 to 58, wherein the first layer differs from the second layer with respect to a physical property. The part of clause 59, wherein the physical property is selected from at least one of strength, toughness, crack resistance, printability, corrosion resistance, fatigue, density, ductility, hardness, shear modulus, coefficient of thermal expansion, thermal conductivity, electrical resistivity, creep, and stiffness. The part of any one of clauses 54 to 60, wherein the part is configured as at least one of an aerospace component, an automotive component, a transportation component, and a building and construction component. 62. The part of any one of clauses 54 to 61, wherein the first powder comprises at least one of metallic particles, polymer particles, and ceramic particles.

63. The part of clause 62, wherein the second powder comprises at least one of metallic particles, polymer particles, and ceramic particles.

64. The part of any one of clauses 54 to 63, wherein the first powder comprises at least one of titanium particles, titanium alloy particles, aluminum particles, aluminum alloy particles, nickel particles, nickel alloy particles, iron particles, iron alloy particles, cobalt particles, cobalt alloy particles, copper particles, copper alloy particles, molybdenum particles, molybdenum alloy particles, magnesium particles, magnesium alloy particles, tantalum particles, tantalum alloy particles, tungsten particles, tungsten alloy particles, zinc particles, zinc alloy particles, silver particles, silver alloy particles, chromium particles, chromium alloy particles, tin particles, tin alloy particles, gold particles, gold alloy particles, platinum particles, platinum alloy particles, zirconium particles, and zirconium alloy particles.

65. The part of clause 64, wherein the second powder comprises at least one of titanium particles, titanium alloy particles, aluminum particles, aluminum alloy particles, nickel particles, nickel alloy particles, iron particles, iron alloy particles, cobalt particles, cobalt alloy particles, copper particles, copper alloy particles, molybdenum particles, molybdenum alloy particles, magnesium particles, magnesium alloy particles, tantalum particles, tantalum alloy particles, tungsten particles, tungsten alloy particles, zinc particles, zinc alloy particles, silver particles, silver alloy particles, chromium particles, chromium alloy particles, tin particles, tin alloy particles, gold particles, gold alloy particles, platinum particles, platinum alloy particles, zirconium particles, and zirconium alloy particles.

[0080] One skilled in the art will recognize that the herein described methods, processes, systems, apparatus, components, devices, operations/actions, and objects, and the discussion accompanying them, are used as examples for the sake of conceptual clarity and that various configuration modifications are contemplated. Consequently, as used herein, the specific examples/embodiments set forth and the accompanying discussion are intended to be representative of their more general classes. In general, use of any specific exemplar is intended to be representative of its class, and the non-inclusion of specific components, devices, operations/actions, and objects should not be taken as limiting. While the present disclosure provides descriptions of various specific aspects for the purpose of illustrating various aspects of the present disclosure and/or its potential applications, it is understood that variations and modifications will occur to those skilled in the art. Accordingly, the invention or inventions described herein should be understood to be at least as broad as they are claimed, and not as more narrowly defined by particular illustrative aspects provided herein.

Claims

CLAIMS What is claimed is:

1. A powder bed additive manufacturing system comprising:

a powder deposition module adapted to dispose a first layer consisting of a first powder in the powder bed deposition region, and to dispose a second layer consisting of a second powder in the powder bed deposition region in contact with the first layer, wherein the first and second powders differ; and

a joining module adapted to affix at least a selected region of the second layer to at least a selected region of the first layer.

2. The system of claim 1, wherein the powder deposition module is adapted to dispose a third layer consisting of third powder in the powder bed deposition region in contact with the second layer, wherein the first, second, and third powders differ.

3. The system of claim 1, wherein the powder deposition module is adapted to deposit:

a plurality of layers consisting of the second powder in the powder bed deposition region, including the second layer.

4. The system of claim 1, further comprising: a first recycle compartment adapted to receive excess first powder from the powder bed deposition region; and

a second recycle compartment adapted to receive excess second powder from the powder bed deposition region.

5. The system of claim 1, further comprising:

a recycle compartment adapted to receive excess first powder and excess second powder from the powder bed deposition region.

6. The system of claim 1, further comprising:

a first powder reservoir adapted to hold the first powder and communicating with the powder deposition module; and a second reservoir adapted to hold the second powder and communicating with the powder deposition module.

7. The system of claim 6, wherein the powder deposition module comprises:

a first re-coater adapted to dispose layers consisting of the first powder in the powder bed deposition region from the first reservoir.

8. The system of claim 7, wherein the powder deposition module comprises:

a second re-coater adapted to dispose layers consisting of the second powder in the powder bed deposition region from the second reservoir.

9. The system of claim 6, wherein the powder deposition module comprises:

a dispenser communicating with the first reservoir and second reservoir, the dispenser adapted to selectively receive the first powder from the first reservoir or the second powder from the second reservoir; wherein the dispenser is further adapted to dispose layers consisting of the first powder in the powder bed deposition region from the first reservoir, and layers consisting of the second powder in the powder bed deposition region from the second reservoir.

10. The system of claim 6, wherein the powder deposition module comprises:

a dispenser communicating with the first reservoir and the second reservoir, the dispenser adapted to blend the first powder from the first reservoir with the second powder from the second reservoir in a preselected ratio to form blended powder; and wherein the dispenser is adapted to dispose layers consisting of the blended powder in the powder bed deposition region.

11. The system of claim 1, wherein the first powder comprises at least one of metallic particles, polymer particles, and ceramic particles.

12. The system of claim 11, wherein the second powder comprises at least one of metallic particles, polymer particles, and ceramic particles.

13. The system of claim 1, wherein the first powder comprises at least one of titanium particles, titanium alloy particles, aluminum particles, aluminum alloy particles, nickel particles, nickel alloy particles, iron particles, iron alloy particles, cobalt particles, cobalt alloy particles, copper particles, copper alloy particles, molybdenum particles, molybdenum alloy particles, magnesium particles, magnesium alloy particles, tantalum particles, tantalum alloy particles, tungsten particles, tungsten alloy particles, zinc particles, zinc alloy particles, silver particles, silver alloy particles, chromium particles, chromium alloy particles, tin particles, tin alloy particles, gold particles, gold alloy particles, platinum particles, platinum alloy particles, zirconium particles, and zirconium alloy particles.

14. The system of claim 13, wherein the second powder comprises at least one of titanium particles, titanium alloy particles, aluminum particles, aluminum alloy particles, nickel particles, nickel alloy particles, iron particles, iron alloy particles, cobalt particles, cobalt alloy particles, copper particles, copper alloy particles, molybdenum particles, molybdenum alloy particles, magnesium particles, magnesium alloy particles, tantalum particles, tantalum alloy particles, tungsten particles, tungsten alloy particles, zinc particles, zinc alloy particles, silver particles, silver alloy particles, chromium particles, chromium alloy particles, tin particles, tin alloy particles, gold particles, gold alloy particles, platinum particles, platinum alloy particles, zirconium particles, and zirconium alloy particles.

15. The system of claim 1, wherein the first powder has a first median particle size in a range of 1 pm to 300 pm.

16. The system of claim 15, wherein the second powder has a second median particle size in a range of 1 pm to 300 pm.

17. The system of claim 16, wherein the first median particle size differs from the second median particle size.

18. The system of claim 17, wherein a ratio of the first median particle size to the second median particle size is in a range of 2: 1 to 20: 1.

19. The system of claim 1, wherein: a median particle size of the first powder differs from a median particle size of the second powder; and

the system further comprises a sieve adapted to sort the first powder and the second powder from powder in the recycle compartment.

20. The system of claim 1, wherein the first powder is magnetic and the second powder is non-magnetic.

21. The system of claim 20, further comprising:

a magnetic apparatus adapted to separate the first powder from the second powder.

22. The system of claim 1, wherein a bulk density of the first powder differs from a bulk density of the second powder.

23. The system of claim 1, wherein the joining module comprises a binder deposition module adapted to deposit a binder on at least a selected region of an exposed layer of powder in the powder bed deposition region, binding the selected region of the layer of powder to an immediately adjacent underlying layer.

24. The system of claim 1, wherein the joining module comprises a laser module adapted to direct a laser beam onto and heat at least a selected region of an exposed layer of powder in the powder bed deposition region, fusing the selected region of the exposed layer of powder to an immediately adjacent underlying layer.

25. The system of claim 1, wherein the joining module comprises an electron beam

module adapted to direct an electron beam onto and heat at least a selected region of an exposed layer of powder in the powder bed deposition region, fusing the selected region of the exposed layer of powder to an immediately adjacent underlying layer.

26. The system of claim 1, wherein the powder bed additive manufacturing system is adapted to conduct at least one additive manufacturing process selected from binder jet additive manufacturing, electron beam melting, direct metal laser sintering, selective laser melting, and selective laser sintering.

27. An additive manufacturing method comprising:

depositing a first layer consisting of a first powder on a powder bed deposition surface of a powder bed deposition region;

depositing a second layer consisting of a second powder on at least a region of the first layer, wherein the first powder and the second powder differ; and

affixing at least a region of the first layer to the second layer;

wherein the additive manufacturing method is a powder bed additive manufacturing method.

28. The method of claim 27, further comprising depositing a third layer consisting of third powder in the powder bed deposition region in contact with the second layer, wherein the first powder, the second powder, and the third powder differ.

29. The method of claim 27, further comprising:

depositing a plurality of layers consisting of the second powder in the powder bed deposition region, including the second layer.

30. The method of claim 27, further comprising:

receiving excess second powder from the powder bed deposition region in a second recycle compartment.

31. The method of claim 27, further comprising: receiving excess first powder and excess second powder from the powder bed deposition region in a recycle compartment.

32. The method of claim 27, further comprising maintaining the first powder separate from the second powder prior to depositing the first powder and the second powder in the powder deposition region.

33. The method of claim 32, wherein the first powder is maintained in a first powder reservoir and the second powder is maintained in a second powder reservoir prior to depositing the first powder and the second powder in the powder deposition region.

34. The method of claim 27, further comprising:

depositing layers consisting of the second powder in the powder bed deposition region from a second re-coater, wherein the first re-coater and the second re-coater are not the same re-coater.

35. The method of claim 27, further comprising:

depositing layers consisting of the second powder in the powder bed deposition region from the re-coater.

36. The method of claim 27, further comprising blending the first powder with the second powder in a preselected ratio to form blended powder and depositing layers of the blended powder in the powder bed deposition region.

37. The method of claim 27, wherein the first powder comprises at least one of metallic particles, polymer particles, and ceramic particles.

38. The method of claim 37, wherein the second powder comprises at least one of

metallic particles, polymer particles, and ceramic particles.

39. The method of claim 27, wherein the first powder comprises at least one of titanium particles, titanium alloy particles, aluminum particles, aluminum alloy particles, nickel particles, nickel alloy particles, iron particles, iron alloy particles, cobalt particles, cobalt alloy particles, copper particles, copper alloy particles, molybdenum particles, molybdenum alloy particles, magnesium particles, magnesium alloy particles, tantalum particles, tantalum alloy particles, tungsten particles, tungsten alloy particles, zinc particles, zinc alloy particles, silver particles, silver alloy particles, chromium particles, chromium alloy particles, tin particles, tin alloy particles, gold particles, gold alloy particles, platinum particles, platinum alloy particles, zirconium particles, and zirconium alloy particles.

40. The method of claim 39, wherein the second powder comprises at least one of

titanium particles, titanium alloy particles, aluminum particles, aluminum alloy particles, nickel particles, nickel alloy particles, iron particles, iron alloy particles, cobalt particles, cobalt alloy particles, copper particles, copper alloy particles, molybdenum particles, molybdenum alloy particles, magnesium particles, magnesium alloy particles, tantalum particles, tantalum alloy particles, tungsten particles, tungsten alloy particles, zinc particles, zinc alloy particles, silver particles, silver alloy particles, chromium particles, chromium alloy particles, tin particles, tin alloy particles, gold particles, gold alloy particles, platinum particles, platinum alloy particles, zirconium particles, and zirconium alloy particles.

41. The method of claim 27, wherein the first powder has a first median particle size in a range of 1 pm to 300 pm.

42. The method of claim 41, wherein the second powder has a second median particle size in a range of 1 pm to 300 pm.

43. The method of claim 42, wherein the first median particle size and the second median particle sizes differ.

44. The method of claim 43, wherein a ratio of the first median particle size to the second median particle size is in a range of 2: 1 to 20: 1.

45. The method of claim 27, wherein:

the method further comprises receiving excess first powder and excess second powder from the powder bed region and separating the first powder from the second powder utilizing a sieve.

46. The method of claim 27, wherein the first powder is magnetic and the second powder is non-magnetic.

47. The method of claim 46, further comprising:

receiving excess first powder and excess second powder from the powder bed region and separating the first powder from the second powder utilizing a magnetic apparatus.

48. The method of claim 27, wherein a bulk density of the first powder differs from a bulk density of the second powder.

49. The method of claim 48, further comprising:

receiving excess first powder and excess second powder from the powder bed region and separating the first powder from the second powder utilizing a density sorter.

50. The method of claim 27, further comprising depositing a binder on at least a selected region of an exposed layer of powder in the powder bed deposition region, binding the selected region of the exposed layer of powder to an immediately adjacent underlying layer.

51. The method of claim 27, further comprising contacting at least a selected region of an exposed layer of powder with at least one of a laser beam and an electron beam thereby heating and fusing the selected region of the exposed layer of powder to an immediately adjacent underlying layer.

52. The method of claim 27, wherein the method comprises at least one technique selected from binder jet additive manufacturing, laser powder bed fusion, electron beam melting, direct metal laser sintering, selective laser melting, and selective laser sintering.

53. The method of claim 27, further comprising affixing at least a region of the first layer to the powder bed deposition surface.

54. A part comprising: a first layer formed from a first powder; and

a second layer formed from a second powder and affixed to the first layer, wherein the first and second powders differ, and wherein the part is produced by a powder bed additive manufacturing process.

55. The part of claim 54, further comprising:

a plurality of layers formed from the first powder, including the first layer; and a plurality of layers formed from the second powder, including the second layer.

56. The part of claim 54, further comprising:

a third layer formed from a third powder and affixed to the second layer; wherein the first powder, the second powder, and the third powder differ.

57. The part of claim 54, wherein the second layer has been fused to the first layer using at least one of a laser beam and an electron beam.

58. The part of claim 54, wherein the second layer has been bound to the first layer by a binder.

59. The part of claim 54, wherein the first layer differs from the second layer with respect to a physical property.

60. The part of claim 59, wherein the physical property is selected from at least one of strength, toughness, crack resistance, printability, corrosion resistance, fatigue, brittleness, density, ductility, hardness, shear modulus, coefficient of thermal expansion, thermal conductivity, electrical resistivity, creep, and stiffness.

61. The part of claim 54, wherein the part is configured as at least one of an aerospace component, an automotive component, a transportation component, and a building and construction component.

62. The part of claim 54, wherein the first powder comprises at least one of metallic particles, polymer particles, and ceramic particles.

63. The part of claim 62, wherein the second powder comprises at least one of metallic particles, polymer particles, and ceramic particles.

64. The part of claim 54, wherein the first powder comprises at least one of titanium

particles, titanium alloy particles, aluminum particles, aluminum alloy particles, nickel particles, nickel alloy particles, iron particles, iron alloy particles, cobalt particles, cobalt alloy particles, copper particles, copper alloy particles, molybdenum particles, molybdenum alloy particles, magnesium particles, magnesium alloy particles, tantalum particles, tantalum alloy particles, tungsten particles, tungsten alloy particles, zinc particles, zinc alloy particles, silver particles, silver alloy particles, chromium particles, chromium alloy particles, tin particles, tin alloy particles, gold particles, gold alloy particles, platinum particles, platinum alloy particles, zirconium particles, and zirconium alloy particles.

65. The part of claim 64, wherein the second powder comprises at least one of titanium particles, titanium alloy particles, aluminum particles, aluminum alloy particles, nickel particles, nickel alloy particles, iron particles, iron alloy particles, cobalt particles, cobalt alloy particles, copper particles, copper alloy particles, molybdenum particles, molybdenum alloy particles, magnesium particles, magnesium alloy particles, tantalum particles, tantalum alloy particles, tungsten particles, tungsten alloy particles, zinc particles, zinc alloy particles, silver particles, silver alloy particles, chromium particles, chromium alloy particles, tin particles, tin alloy particles, gold particles, gold alloy particles, platinum particles, platinum alloy particles, zirconium particles, and zirconium alloy particles.