WO2020014028A1

WO2020014028A1 - Method and system for increasing density in a powder bed, and article produced therefrom

Info

Publication number: WO2020014028A1
Application number: PCT/US2019/040135
Authority: WO
Inventors: Neville Whittle; Deborah Murphy WILHELMY; Justen SCHAEFER; Adam TRAVIS; Nicholas BILLMYER; Eli ALMAN; Jacob RAPLEE
Original assignee: Arconic Inc
Current assignee: Howmet Aerospace Inc
Priority date: 2018-07-10
Filing date: 2019-07-01
Publication date: 2020-01-16
Anticipated expiration: 2021-01-10

Abstract

A method and system for improving the density in a powder bed, and an article produced therefrom is provided. The system comprises a powder deposition surface and a powder deposition module. The powder deposition surface is adapted to receive powder. The powder deposition module is adapted to dispose a layer of powder on the surface and is adapted to compact the layer.

Description

TITLE

METHOD AND SYSTEM FOR INCREASING DENSITY IN A POWDER BED,

AND ARTICLE PRODUCED THEREFROM

CROSS-REFERENCE

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

62/695,916, which was filed on July 10, 2018. The contents of which is incorporated by reference into this specification.

FIELD OF USE

[0002] The present disclosure relates to a method and a system for increasing density in a powder bed, and to an article produced using the method and/or system. In certain embodiments, the method and system are applied in an additive manufacturing process such as, for example, a binder jet additive manufacturing process.

BACKGROUND

[0003] Additive manufacturing means a process of joining materials to make objects from three dimensional model data, usually layer upon layer, as opposed to subtractive

manufacturing methodologies, as defined in ASTM F2792-l2a entitled“Standard

Terminology for Additively Manufacturing Technologies”. Non-limiting examples of additive manufacturing processes useful in producing products from metallic feedstock include, for instance, DMLS (direct metal laser sintering), SLM (selective laser melting), SLS (selective laser sintering), and EBM (electron beam melting), among others. Any suitable feedstock may be used, including a powder, a wire, and combinations thereof. In some embodiments, the additive manufacturing feedstock is comprised of powder. There are challenges in obtaining suitable density in an additively manufactured part.

SUMMARY

[0004] According to one aspect, the present disclosure provides a powder bed additive manufacturing system. The system comprises a powder deposition surface and a powder deposition module. The powder deposition surface is adapted to receive powder. The powder deposition module is adapted to dispose a layer of powder on the powder deposition surface and also is adapted to compact the layer of powder. In various embodiments, the powder deposition module is adapted to apply a pressure of at least 1 pound per square inch (“psi”) to a layer of powder disposed by the powder deposition module.

[0005] According to another aspect, the present disclosure provides a powder bed additive manufacturing method. The method comprises depositing a layer of powder on a surface and compacting the layer of powder. In various embodiments, compacting the layer of powder comprises applying a pressure of at least 1 psi to the layer of powder.

[0006] According to yet another aspect, the present disclosure provides a part preform produced by a powder bed additive manufacturing process. The part preform comprises powder and a binder binding the powder in the part preform. A porosity of the part preform is less than 50% by volume such as, for example, less than 40% by volume, less than 35% by volume, or less than 30% by volume.

[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 non-limiting embodiment of a powder bed including powder with at least two different sizes according to the present disclosure;

[0010] FIG. 2 is a schematic depiction of a non-limiting embodiment of a powder bed including powder with at least two different general shapes according to the present disclosure;

[0011] FIG. 3 is a schematic depiction of a non-limiting embodiment of an additive manufacturing system including a plate according to the present disclosure; [0012] FIG. 4 is a schematic depiction of a non-limiting embodiment of a powder layer compaction system including a blade and a roller according to the present disclosure;

[0013] FIG. 5 is a schematic depiction of a non-limiting embodiment of a powder layer compaction system including a blade and a pressing blade according to the present disclosure;

[0014] FIG. 6A is a schematic front view of a non-limiting embodiment of an additive manufacturing system including a powder deposition module in a first position according to the present disclosure;

[0015] FIG. 6B is a schematic front view of a non-limiting embodiment of the additive manufacturing system of FIG. 6 A including the powder deposition module in a second position according to the present disclosure;

[0016] FIG. 6C is a schematic front view of a non-limiting embodiment of the additive manufacturing system of FIG. 6 A including the powder deposition module in a third position according to the present disclosure;

[0017] FIG. 6D is a schematic front view of a non-limiting embodiment of the additive manufacturing system of FIG. 6 A including the powder deposition module in a fourth position according to the present disclosure;

[0018] FIG. 7 is a schematic depiction of a non-limiting embodiment of a powder deposition module including a first roller having a crown shape according to the present disclosure;

[0019] FIG. 8 is a schematic depiction of a non-limiting embodiment of a powder deposition module including a first scraper according to the present disclosure;

[0020] FIG. 9 is a schematic depiction showing aspects of a non-limiting embodiment of an additive manufacturing system including a vibratory unit according to the present disclosure; and

[0021] FIG. 10 is a graph illustrating density versus pressure applied by a piston for steel particle samples A-E.

[0022] 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

[0023] Various embodiments are described and illustrated herein to provide an overall understanding of the structure, function, and use of the disclosed methods, systems, and articles. 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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.

[0028] 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. [0029] 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.

[0030] As used herein,“substantially spherical” means a shape having a sphericity of at least 0.8, such as, for example, at least 0.85 or at least 0.92.

[0031] As used herein,“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).

[0032] As used herein,“Dio” of a powder refers to the diameter at which 10% of the volume of the particles in the powder have a smaller diameter.

[0033] As used herein,“D90” of a powder refers to the diameter at which 90% of the volume of the particles in the powder have a smaller diameter.

[0034] As used herein, particle size was determined in accordance with ASTM standard B822.

[0035] In some embodiments, a binder jet additive manufacturing system comprises a powder bed, a platform, a powder deposition module, and a binder deposition module. The powder bed can be adapted to receive powder and can comprise the platform and a layer or layers of powder. The powder can be retrieved from a reservoir by the powder deposition module and can be deposited in a layer in the powder bed. The binder deposition module can bind together the powder in one or more selected regions of the layer of powder by depositing binder on one or more regions of the layer. The sequence of depositing a layer of powder and depositing a binder on a selected region or regions of the layer can be repeated as needed to produce a part preform in the powder bed. The part preform can include powder and binder.

[0036] Typically, the powder bed can have a low density and a high porosity, which can affect the density and porosity of a part preform produced therefrom. A porous and low- density part preform can have an undesirable low-tensile strength. Additionally, the part preform may have to be subjected to additional processing steps to increase the density of the part, such as, for example, infiltration with a secondary material and/or sintering. Moreover, the powder bed may have defects (e.g., gaps and non-uniform layers), which can become defects in the part preform produced therefrom. [0037] In view of the above drawbacks, a method and system for increasing the density in a powder bed and an article produced therefrom is provided. The powder bed may have increased uniformity in layer thickness of powder particle layers. The increase in density can increase the strength of a part preform created from the powder bed having increased density. Additionally, the part preform can result in a green part having an increased strength and/or density. Sintering the higher density green part can require less energy input ( e.g time in a furnace, temperature) to produce a sintered part having the required minimum density than sintering a less dense green part. Additionally, the higher density green part may shrink and/or distort less during the sintering process than a less dense green part. The higher density green part may comprise geometries that were previously unattainable in an additive manufacturing process due to the increased powder bed density provided by methods and systems according to the present disclosure. Additionally, a sintered part produced from a higher density green part produced by the methods and systems according to the present disclosure may include fewer defects due to reduction or minimization of defects in the powder bed.

[0038] According to the present disclosure, a method for powder bed additive manufacturing includes depositing a layer of powder on a surface and compacting the layer. In various embodiments, compacting the layer comprises at least one of moving a plate into contact with the layer and exerting pressure on the layer with the plate, and moving a press into contact with the layer and applying pressure to the layer with the press. In various embodiments, compacting includes applying a pressure of at least 1 psi to the powder layer, such as, for example, at least 1,000 psi. In certain embodiments, the layer is vibrated.

[0039] Referring to FIG. 1, a schematic depiction of a non-limiting embodiment of a powder bed 100 having powder with at least two least two different sizes is provided. For example, the powder bed 100 can comprise a first powder fraction 102 having a first median particle size and a second powder fraction 104 having a second median particle size. The first and second sizes can differ. 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, 6: 1 to 9: 1, or 7: 1. In various embodiments, the first median particle size can be in a range of 50 nm to 325 pm, such as, for example, 1 pm to 325 pm, 20 pm to 325 pm, 20 pm to 300 pm, 20 pm to 250 pm, 20 pm to 200 pm, 30 pm to 150 pm, or 30 pm to 90 pm. In certain embodiments, the second median particle size can be in a range of 50 nm to 65 pm, such as, for example, 1 nm to 65 pm, 5 pm to 50 pm, 2.5 pm to 32.5 pm, 5 pm to 40 pm, or 5 pm to 30 pm. Providing at least two different median particle sizes of the powder in the powder bed 100 can facilitate a higher density packing of the powder bed with powder.

[0040] The particle size can affect the layer thickness of the powder. For example, the layer thickness can be from 1 time to 10 times the median particle size of the powder, such as, for example, 2 to 8 times the median particle size, 2 to 4 times the median particle size, or 3 times the median particle size. For example, the layer thickness can be from 5 pm to 3,250 pm, such as, for example, 10 pm to 2,000 pm, 10 pm to 1,000 pm, 50 pm to 300 pm, or 1,000 pm. In certain embodiments, the powder bed 100 can comprise powder of a single median particle size.

[0041] In various embodiments, the median particle size of the powder in the powder bed 100 can be in a range of 50 nm to 325 pm, such as, for example, 1 pm to 325 pm, 5 pm to 325 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 150 pm, 15 pm to 45 pm, 20 pm to 65 pm, 25 pm to 45 pm, 50 pm to 150 pm, 65 pm to 90 pm, 10 pm to 200 pm, 5 pm to 30 pm, 30 pm to 90 pm, or 5 pm to 50 pm. In certain embodiments, the median particle size of the powder in the powder bed 100 can be less than 325 pm such as, for example, less than 300 pm, less than 275 pm, less than 250 pm, less than 225 pm, less than 200 pm, less than 175 pm, less than 150 pm, less than 125 pm, less than 100 pm, less than 90 pm, less than 70 pm, less than 10 pm, or less than 1 pm,.

[0042] In various embodiments, the powder bed 100 can comprise powder having a span of at least 0.1. In various embodiments, the powder in the powder bed 100 can have a span in a range of 1 to 5 such as, for example, 1.5 to 5, 1.6 to 5, 1.7 to 5, 1.8 to 5, 1.9 to 5, 2 to 5, 2.1 to 5, 2.2 to 5, 2.3 to 5, 2.4 to 5, 2.5 to 5, 2.6 to 5, 2.7 to 5, 2.8 to 5, 2.9 to 5, 3 to 5, 4 to 5, 1 to 4, 1.5 to 4, 1 to 3, 1.5 to 3, 2 to 4, or 2 to 3. A powder with a span in the ranges described herein can increase the density of the powder in the powder bed 100 by at least 2% such as, for example, at least 5%, at least 10%, or at least 20%. The span is based on the median particle size (Dso), Dio, and D90 as shown in equation 1.

Equation 1

I) 90 D 10

Span

D 50 [0043] The D lo of the powder can be in a range of 0.1 pm to 200 pm such as, for example, 1 pm to 50 pm, 5 pm to 45 pm, 10 pm to 20 pm, 10 pm to 50 pm, 1 pm to 125 pm, 10 pm to 30 pm, 1 pm to 45 pm, 1 pm to 30 pm, 30 pm to 90 pm, or 45 pm to 65 pm. The D90 of the powder can be in a range of 10 pm to 500 pm such as, for example, 20 pm to 400 pm, 50 pm to 200 pm, 100 pm to 200 pm, 75 pm to 150 pm, 30 pm to 200 pm, 30 pm to 60 pm, 45 pm to 90 pm, 55 pm to 75 pm, 75 pm to 175 pm, or 80 pm to 105 pm. In various embodiments involving binder jet additive manufacturing, the Dio of the powder in the powder bed 100 can be in a range of 1 pm to 125 pm such as, for example, 10 pm to 30 pm, the median particle size of the powder in the powder bed 100 can be in a range of 10 pm to 150 pm such as, for example, 15 pm to 45 pm, and the D90 of the powder in the powder bed 100 can be in a range of 30 pm to 200 pm such as, for example, 30 pm to 60 pm. In various embodiments involving additive manufacturing utilizing a laser, the Dio of the powder in the powder bed 100 can be in a range of 1 pm to 45 pm such as, for example, 1 pm to 30 pm, the median particle size of the powder in the powder bed 100 can be in a range of 20 pm to 65 pm such as, for example, 25 pm to 45 pm, and the D90 of the powder in the powder bed 100 can be in a range of 45 pm to 90 pm such as, for example, 55 pm to 75 pm. In various embodiments involving additive manufacturing utilizing an electron beam, the Dio of the powder in the powder bed 100 can be in a range of 30 pm to 90 pm such as, for example, 45 pm to 65 pm, the median particle size of the powder in the powder bed 100 can be in a range of 50 pm to 150 pm such as, for example, 65 pm to 90 pm, and the D90 of the powder in the powder bed 100 can be in a range of 75 pm to 175 pm such as, for example, 80 pm to 105 pm.

[0044] In various embodiments, the powder can be produced with a desired span. In some embodiments, two or more powders can be blended together to achieve the desired span before providing the powder to the powder bed 100. In various embodiments, the powder can be manually mixed prior to adding the powder to an additive manufacturing system or dynamically mixed by an additive manufacturing system to achieve the desired span. For example, an additive manufacturing system can have two or more hoppers which have powders that have differing particle sizes. The two more or more hoppers can feed into a reservoir a desired amount of powder from each hopper to achieve the desired span and/or size ratio. The two or more powders can be blended together utilizing a mixer until the powder is suitable for additive manufacturing ( e.g substantially homogeneous). [0045] In various embodiments, the first and second powder 102, 104 can be substantially spherical in shape. In certain embodiments, as illustrated in FIG. 2, a powder bed 200 can have a first powder fraction 206 having a first general particle shape and a second powder fraction 208 having a second general particle shape. The first and second particle shapes can differ. For example, the first general particle shape can be irregular. The irregularly shaped powder of the first powder fraction 206 may include at least one sharp edge having an acute exterior angle. In various embodiments, the second general particle shape can be

substantially spherical. Utilizing certain combinations of powder fractions with different general shapes can enhance packing density of the powder in the powder bed 200. In various embodiments, including two or more powder fractions having differing general shapes in the powder bed 200 can result in green parts requiring less energy during sintering to achieve a desired minimum density than green parts produced from powder beds that do not include multiple powder fractions with different general shapes. The shapes of the powder in the powder fractions in the powder bed 200 can be chosen to increase the packing density of the powder bed 200.

[0046] In various embodiments, including powder fractions with different powder particle shapes in the powder bed 200 can increase the efficiency of sintering a part preform produced from the powder bed 200. For example, including irregularly shaped powder in the powder bed 200 can enhance sintering of a part preform produced from the powder bed 200 due to the sharp angle present at the edges of the irregularly shaped powder and higher surface area, which can allow the particles to heat more efficiently. For example, the sharp angles present at the edges of higher surface area powder can be less stable than sphere shaped powder. The instability at the edges can promote increased mass diffusion which can lower the surface area of the powder.

[0047] In certain embodiments, the powder in the powder bed comprises at least one of metallic particles, plastic particles, and ceramic particles. In various embodiments, the powder can comprise, for example, 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, tantalum particles, tantalum alloy particles, tungsten particles, and tungsten alloy particles. In various embodiments, the powder can comprise at least one of titanium particles and titanium alloy particles. If present, ceramic particles can comprise, for example, at least one of non-oxide ceramic particles and oxide ceramic particles. In various examples, the ceramic particles can comprise at least one of an oxide, a carbide, a nitride, and a boride.

[0048] Referring to FIG. 3, a schematic depiction of a front view of a non-limiting embodiment of an additive manufacturing system 300 including a plate 322 is provided. The additive manufacturing system 300 can comprise a powder bed 310, a platform 312, a powder deposition module 314, and a binding module 316. The powder bed 310 can be adapted to receive powder. The powder bed 310 can comprise the platform 312 and a layer or layers of powder.

[0049] The powder deposition module 314 can deposit the powder in the powder bed 310. In various embodiments, the powder deposition module 314 can obtain powder from a powder reservoir 318. The powder deposition module 314 can move the obtained powder to the powder bed 310 and deposit a layer of the powder in the powder bed 310. In certain embodiments, instead of including reservoir 318, the powder deposition module 314 can source powder from a powder hopper (not shown) and deposit the powder as a layer in the powder bed 310. In various embodiments, the powder deposition module 314 can source powder from two or more powder hoppers (not shown), mix the powder from the powder hoppers, and deposit them as a layer in the powder bed 310. In various embodiments, the reservoir 318 can include at least two compartments (not shown) to hold different fractions of powder. In various embodiments, the reservoir 318 can receive powder from two or more powder hoppers (not shown) and blend the powders together such that the resulting blended powder is suitable for additive manufacturing ( e.g substantially homogeneous).

[0050] One or more selected regions of the powder in the one or more layers of powder in the powder bed 310 can be bound together by the binding module 316. For example, the binding module 316 can be a binder deposition module adapted to deposit a binder in one or more predetermined regions of powder layers deposited in the powder bed 310. In various embodiments, the binder can be a liquid binder.

[0051] In various embodiments, the binding module 316 can comprise an energy source adapted to selectively sinter and/or melt powder in one or more predetermined regions of powder layers deposited in the powder bed 310. For example, the energy source can comprise at least one of a laser and an electron beam gun. [0052] The bound particles can form all or a portion of a part preform, wherein the part preform includes powder bound together. For example, the part preform can include powder and binder holding the powder together. The sequence of depositing a layer of powder and binding a selected region or regions of the layer can be repeated as needed to produce the part preform.

[0053] The additive manufacturing system 300 can comprise the plate 322, which can be adapted to contact a surface 3 lOa of the powder bed 310. The plate 322 can be configured to apply pressure to the powder bed 310 and compact the powder bed 310. The pressure exerted by the plate 322 can increase the density of all or a portion of the powder bed 310, such as in a layer of powder deposited in the powder bed 310. In various embodiments, the plate 322 can compact all or a portion of the powder deposited in the powder bed 310 after the powder deposition module 314 deposits the powder in the powder bed 310. In various examples, the plate 322 can apply a compaction force to the powder bed 310 generally orthogonal to the depositing direction of the powder by the powder deposition module 314.

[0054] The size and shape of the plate 322 can vary among various embodiments of system 300. For example, the plate 322 can have a contact area that is similar to the exposed surface area of the surface 3 lOa of the powder bed 310.

[0055] In various embodiments, the plate 322 can have a contact area that is less than the exposed surface area of the surface 3 lOa of the powder bed 310. The plate 322 can compact a first region of the powder bed 310 and can be adapted to move and compact a second region of the powder bed 310, different than the first region.

[0056] The plate 322 can be adapted to apply a variable pressure to the powder bed 310. For example, the plate 322 can apply a first pressure to the first region of the powder bed 310, and apply a second pressure to a second region of the powder bed 310. Varying the applied pressure among different regions of the powder bed 310 can be used to create a uniform layer of powder and, in certain embodiments, create a denser area of the layer of powder for printing. In various embodiments, the plate 322 can compact the layer of powder until a selected density or a selected thickness of the layer is achieved in the region to which the pressure is applied.

[0057] In certain embodiments, the additive manufacturing system 300 can include at least two plates (not shown). For example, the system may include a plurality of plates arranged in a checkerboard pattern. The plates can be controlled individually or collectively. The plates can be stationary or adapted to move relative to the powder bed 310. Regardless of the plate 322 configuration, the individual plates can apply a pressure to all or a region of the powder layer to compact the powder layer.

[0058] With reference to FIGs. 4 and 5, in various embodiments, which may or may not also include the plate 322, the powder deposition module 314 or additive manufacturing system can comprise a compaction system 400, 500 that includes a press. The press can comprise at least one of a roller 426 (FIG. 4) and a pressing blade 530 (FIG. 5). Referring to FIG. 4, a schematic front view of a non-limiting embodiment of a compaction system 400 including a blade 424 and a roller 426 is provided. The roller 426 can be operatively coupled to the blade 424 by connector 428. The connector 428 can facilitate communication between the blade 424 and the roller 426.

[0059] The blade 424 can be configured to obtain powder from a reservoir, such as, for example, reservoir 318, and can deposit the retrieved particles in the powder bed 310. For example, the blade 424 can push powder into the powder bed 310. The blade 424 can be disposed at a depositing depth into the powder bed 310, at a distance above the existing surface of the powder bed 310, and can move across the powder bed 310 in a direction 446 to deposit the obtained powder across the powder bed 310 to produce a layer of powder having a first density. In various embodiments, the blade 424 can provide a level and/or smooth surface 3 lOd on the powder bed 310.

[0060] The roller 426 can be configured to follow the blade 424 and apply pressure to the powder deposited on the powder bed 310, which can compact the powder bed 310. The roller 426 can thereby increase a density of the powder bed 310. For example, a pre-compaction section 310b of the powder bed 310 can have a first density, and a post-compaction section 3 lOc of the powder bed 310 can have a second density. The first and second densities can differ. In various examples, the roller 426 can apply a compaction force to the powder bed 310 generally orthogonal to the direction 446 of movement of the blade 424 to deposit the powder in the powder bed 310. In various embodiments, the roller 426 can compact the powder bed 310 after the blade 424 deposits the powder in the powder bed 310. In various embodiments, the blade 424 can compact the powder bed 310 and can increase a density of the powder bed 310. [0061] Referring to FIG. 5, a schematic front view of a non-limiting embodiment of a compaction system 500 including the blade 424 and the pressing blade 530 is provided. The pressing blade 530 can be operatively coupled to the blade 424. The pressing blade 530 can be configured to apply a pressure to the powder bed 310 and compact the powder bed 310. The pressing blade 530 can increase the density of the powder bed 310. For example, a pre- compaction section 310b of the powder bed 310 can have the first density, and a post- compaction section 3 lOc of the powder bed 310 can have the second density. The first and second densities can differ. In various examples, the pressing blade 530 can apply a compaction force to the powder bed 310 generally orthogonal to the direction 446 of movement of the blade 424 to deposit the powder in the powder bed 310. In various embodiments, the pressing blade 530 can compact the powder bed 310 after the blade 424 deposits the powder in the powder bed 310.

[0062] Referring to FIG. 6A, a schematic depiction of a non-limiting embodiment of an additive manufacturing system 600 including a powder deposition module 614 in a first position is provided. As illustrated in FIG. 6A, the additive manufacturing system 600 comprises the powder bed 310, the platform 312, the powder deposition module 614, the powder reservoir 318, and a vertically movable reservoir platform 620. In certain embodiments, the additive manufacturing system 600 can also comprise a binding module (not shown).

[0063] The powder deposition module 614 can comprise a first roller 6l4a and a second roller 6l4b (e.g., backup roller). The first roller 6l4a can have a first diameter, and the second roller 6l4b can have a second diameter that is larger than the first diameter.

[0064] Decreasing a diameter of the first roller 614a can decrease the portion of the first roller 6l4a that is in contact with the powder bed 310, which can increase the pressure applied by the first roller 6l4a to the powder bed 310. However, if the first roller 6l4a has a relatively small diameter and/or is applying large pressures, the first roller 6l4a can deflect along its length, and the pressure applied to the powder bed 310 may not be uniform. The resulting variation in applied pressure along the length of the first roller 614a may produce a part preform with varying densities and inaccurate features due to variations in layer thickness and/or defects in the layer. Thus, using a second roller 6l4b to support the length of the first roller 614a can limit deflection of the first roller 614a and facilitate uniform application of pressure by the first roller 6l4a to the powder bed 310. [0065] FIG. 6 A shows the powder deposition module 614 in a first position. The powder reservoir platform 620 is shown in a position that has raised the level of powder in the reservoir 318 above the elevation of the existing powder bed 310. The powder deposition module 614 can contact the exposed powder and facilitate movement of the powder to the powder bed 310. For example, the powder deposition module 614 can move laterally from the first position illustrated in FIG. 6A to a second position illustrated in FIG. 6B so that the first roller 6l4a pushes powder 632 laterally out of the reservoir 318 and toward the powder bed 310.

[0066] The powder deposition module 614 can move laterally from the second position illustrated in FIG. 6B to a third position illustrated in FIG. 6C. The lateral movement of the powder deposition module 614 can deposit the powder 632 pushed from the reservoir 318 along the top surface of the powder bed 310. During the lateral movement, the powder deposition module 614 can apply pressure to the powder 632 distributed along the powder bed 310 to compact the powder 632 into a layer 644 having an increased density.

[0067] The powder deposition module 614 can move further laterally from the third position illustrated in FIG. 6C to a fourth position illustrated in FIG. 6D. The lateral movement of the powder deposition module 614 to the fourth position can complete deposition and

compaction of the mass of powder 632 pushed from the reservoir 318 into a layer along the powder bed 310, providing a compacted (densified) powder layer 644 in the powder bed 310. In certain embodiments, a portion of the powder 632 pushed from the reservoir 318 by the lateral movement of the powder deposition module 614 shown in FIGs. 6A-6D may not be deposited in the layer 644 and can be removed from the print bed 310 and returned to the reservoir 318 or otherwise disposed of.

[0068] Referring to FIG. 7, a schematic depiction from a side of aspects of a non-limiting embodiment of a powder deposition module 700 including a first roller 7l4a having a crown shape is provided. As illustrated, the powder deposition module comprises the first roller 714a and a second roller 714b. The second roller 714b can be configured so that its circumferential surface is in contact with the circumferential surface of the first roller 7l4a. The second roller 714b can limit the deflection of the first roller 714a and facilitate the application of pressure by the first roller 7l4a to the powder bed 310. The first roller 7l4a can have a crown shape, which can limit the deflection of the first roller 714a and can facilitate uniform application of pressure by the first roller 7l4a to the powder bed 310. In certain embodiments, the crown shape can control a contact stress of the first roller 714a induced by application of pressure to the powder bed 310. In various embodiments, the first roller 714a can have at least one of a generally cylindrical shape, a crown shape, a double crown shape, a variable crown shape, and a stepped shape.

[0069] As noted, the second roller 7l4b can have a variable shape. For example, the second roller 714b can have a variable crown shape complimentary to a variable crown shape of the first roller 7l4a. The complimentary variable crown shapes can adjust the pressure applied to the powder bed 310 dynamically. For example, if the position of the second roller 7l4b changes with resect to the position of the first roller 714a, the pressure applied by the first roller 714a to the powder bed 310 can change.

[0070] Referring to FIG. 8, a schematic side view depiction of certain aspects of a non limiting embodiment of a powder deposition module 800 including a first scraper 834 is provided. The powder deposition module 800 comprises a first roller 8l4a and a second roller 814b in contact with the first roller 814a. As the first roller 814a traverses across a powder bed, such as powder bed 310, powder may adhere to a surface 8l4ai of the first roller 8l4a. The adhered powder may limit the ability of the powder deposition module 800 to deposit a uniform layer of powder. In order to limit powder particle buildup on the surface 8l4ai, a first scraper 834 can be configured to remove powder from the surface 8l4ai of the first roller 8l4a as the first roller, for example, rotates about its axis of rotation. For example, the first scraper 834 can be disposed proximal to the first roller 8l4a such that the first scraper 834 contacts powder on the surface 8l4ai of the first roller 8l4a.

[0071] In various embodiments, to further limit powder particle buildup on the surface 8l4ai, a second scraper 836, shown in FIG. 8, can be configured to remove powder from a surface 8l4bi of the second roller 8l4b. For example, the second scraper 836 can be disposed proximal to the second roller 8l4b such that the second scraper 836 contacts powder on the surface 8l4bi of the second roller 8l4b and removes the powder.

[0072] In various embodiment, the first roller 8l4a and/or second roller 8l4b can comprise a coating on an outer surface. The coating may provide resistance to powder particle pickup and/or to scratches from the first scraper 834 and/or second scraper 836. The coating may be any suitable protective and/or non-stick coating as known by one of ordinary skill in the art. [0073] The first roller 8l4a and second roller 8l4b can be configured to rotate. For example, the first roller 814a can rotate in direction 838a or direction 838b. The second roller 814b can rotate in direction 840a or direction 840b. In various embodiments, the first roller 8l4a rotates in direction 838a, and the second roller 814b rotates in direction 840a. In another embodiment, the first roller 814a rotates in direction 838b, and the second roller 814b rotates in direction 840b. In various embodiments, the second roller 8l4b can contact the first roller 8l4a, and when the second roller 8l4b rotates, the first roller 8l4a rotates due to friction caused by the contact. In various embodiments, the first roller 8l4a and the second roller 8l4b can be connected by a gearbox (not shown).

[0074] In various embodiments, the direction of rotation of the first roller 8l4a can be in a direction opposite a direction of linear movement of the powder deposition module 800 relative to a surface of a powder bed. For example, when the powder deposition module 800 moves in direction 846a, the first roller 814a can rotate in direction 838a. When the powder deposition module 800 moves in a direction 846b, the first roller 8l4a can rotate in direction 838b.

[0075] In various other embodiments, the direction of rotation of the first roller 8l4a can be in the same direction as a direction of linear movement of the powder deposition module 800 relative to a surface of a powder bed. For example, when the powder deposition module 800 moves in direction 846b, the first roller 814a can rotate in direction 838a. When the powder deposition module 800 moves in direction 846a, the first roller 8l4a can rotate in direction 838b.

[0076] The pressure applied by the plate 322, the roller 426, the pressing blade 530, the first roller 6l4a, the first roller 7l4a, and/or the first roller 8l4a to the powder bed 310 can be at least 1 psi, such as, for example, at least 10 psi, at least 100 psi, at least 1,000 psi, at least 3,000 psi, at least 5,000 psi, or at least 10,000 psi. In various embodiments, the pressure applied by the plate 322, the roller 426, the pressing blade 530, the first roller 6l4a, the first roller 7l4a, and/or the first roller 8l4a to the powder bed 310 can be in a range from 1 psi to 10,000 psi such as, for example, from 1 to 10 psi, from 10 to 100 psi, from 100 to 1,000 psi, from 1,000 psi to 10,000 psi, or from 5,000 psi to 10,000 psi. The plate 322, the roller 426, the pressing blade 530, the first roller 6l4a, the first roller 7l4a, and/or the first roller 8l4a can be configured to apply pressure by, for example, at least one of a spring and an actuator. The actuator may comprise at least one of an electric actuator, a hydraulic actuator, and a pneumatic actuator.

[0077] In various embodiments, the pressure can be applied to the powder bed 310 by the plate 322, the roller 426, the pressing blade 530, the first roller 6l4a, the first roller 7l4a, and/or the first roller 8l4a after the binding module 316 deposits a binder in the powder bed 310. The binder can act as a lubricant to facilitate packing of the powder bed 310. In various embodiments, at least two layers of powder can be deposited and compacted in the powder bed 310 prior to an application of a binder by the binding module 316. In other

embodiments, a single layer of powder can be deposited and compacted in the powder bed prior to an application of a binder by the binding module.

[0078] In various embodiments, the plate 322, the roller 426, the pressing blade 530, the first roller 6l4a, the first roller 7l4a, and/or the first roller 8l4a substantially compact the layer of powder deposited by the powder deposition module 314, 614, 700, 800. In some

embodiments, the plate 322, the roller 426, the pressing blade 530, the first roller 6l4a, the first roller 7l4a, and/or the first roller 8l4a substantially compact a portion of the powder bed 310 or the entire powder bed 310.

[0079] Referring to FIG. 9, a schematic depiction of a front view showing aspects of a non limiting embodiment of an additive manufacturing system 900 including a vibratory unit is provided. In certain embodiments, the system 900 can comprise a plurality of vibratory units 942a-g. The vibratory units 942a-c can be operatively coupled to the platform 312. The vibratory units 942d-g can be operatively coupled to an enclosure 944 disposed adjacent to the powder bed 310. The vibratory units 942a-g can be configured to vibrate and/or oscillate the powder bed 310. The vibrations can cause powder to shift into voids present in the powder bed 310, which can increase the packing density of powder in the powder bed 310.

In various embodiments, the vibratory units 942a-g can comprise at least one of an ultrasonic transducer, a non-ultrasonic transducer, and a vibration motor.

[0080] The vibratory units 942a-g can be configured to operate individually or collectively. For example, vibratory units 942d, 942g can be configured to vibrate a first region 3 lOe of the powder bed 310 while minimizing vibrations in a second region 31 Of of the powder bed 310. The first and second regions 3 lOe, 3 lOf can be different regions of a layer of powder, one or more layers of powder, or combinations thereof. The selective vibrations can increase the density of the selected region of the powder bed 310 while maintaining the integrity of non-selected regions of the powder bed 310, such that any regions of the part preform already formed will not be damaged.

[0081] In various embodiments, a porosity of the part preform produced according to the present disclosure is less than 50% by volume such as, for example, less than 40% by volume, less than 35% by volume, or less than 30% by volume. In various examples, the porosity of the part preform is in a range of 45% to 50% by volume.

[0082] Examples

[0083] Layers including various sizes of powder comprising maraging steel particles suitable for additive manufacturing feedstock were tested for density improvements as a result of applied pressure. The steel particles were substantially spherical. Steel particle sample A included a particle size distribution of 12 pm to 23 pm and a median particle size of 17 pm. Steel particle sample B included a particle size distribution of 20 pm to 36 pm and a median particle size of 27 pm. Steel particle sample C included a particle size distribution of 40 pm to 71 pm and a median particle size of 52 pm. Steel particle sample D included a bimodal particle size distribution of powder. Steel particle sample D comprised a first powder fraction including steel particle sample A and a second powder fraction including steel particle sample C. Steel particle sample E included a particle size distribution of 19 pm to 48 pm and a median particle size of 29 pm.

[0084] 16 cm³ of each sample A-E was weighed and then placed in an individual cylindrical container. A piston having a size similar to the internal diameter of the cylindrical container was positioned inside of the container and in contact with the top surface of the respective powder sample. An initial volume was calculated based on a volume calculation of the cylindrical container and the position of the piston. The piston began to compress the particles by moving downward into the container. As the piston moved downward, the distance the piston traveled and the pressure applied to the powder sample were measured.

The distance the piston traveled was used to determine a corresponding decrease in volume of the respective powder sample. The instantaneous volume of each sample A-E and the respective initial weight of each sample A-E were used to determine the corresponding density of the powder sample. [0085] As illustrated in FIG. 10, graph 1000 depicts the density as calculated in grams per cubic centimeter versus the pressure applied by the piston for the particular powder sample as measured in psi. The x-axis (pressure applied) is in logarithmic scale. Steel particle sample A corresponds to curve 1002; steel particle sample B corresponds to curve 1004; steel particle sample C corresponds to curve 1006; steel particle sample D corresponds to curve 1008; and steel particle sample E corresponds to curve 1010. As illustrated, the density of each sample increased as increased pressure was applied, and the density increased more significantly after an applied pressure of at least 100 psi and at least 1,000 psi. It is believe that the compression trends in this example should apply to various other materials.

[0086] It was observed that applying pressure to powder in the powder bed can increase the density of the powder bed. In various examples including binder jet additive manufacturing, the increase in density will cascade throughout the process. For example, an increased powder bed density may yield an increased green part density, which in turn may yield an increased sintered part density. In various examples including an energy source, an increased powder bed density decreases the porosity of a part produced therefrom and can reduce entrapped gas porosity in the part. Thus, the increased density in a powder bed of an additive manufacturing process can reduce the occurrence of and/or eliminate aberrations in the final part ( e.g ., density lower than specifications, pores, and/or cavitation).

[0087] In some embodiments, the products produced by these methods have commercial end- uses in industrial applications, consumer applications (e.g. consumer electronics and/or appliances) or other areas. For example, the components or resulting products can be utilized in the aerospace field, automotive field, transportation field, building and construction field, in a variety of forms: fasteners, sheet, plate, castings, forgings, extrusions, post processed additive manufacturing forms, among others, including various applications (e.g., structural applications) and components like beams, frames, rails, brackets, bulkheads, spars, ribs, among others.

[0088] 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 deposition surface adapted to receive powder; and a powder deposition module adapted to dispose a layer of powder on the powder deposition surface and adapted to compact the layer. The system of clause 1, wherein the powder deposition module further comprises a plate moveable relative to the surface and adapted to compact a layer of the powder disposed by the powder deposition module. The system of clauses 1-2, wherein the powder deposition module further comprises a blade moveable relative to the powder deposition surface and adapted to deposit and compact a layer of the powder disposed by the powder deposition module. The system of clauses 1-3, wherein the powder deposition module further comprises a press moveable relative to the powder deposition surface and adapted to compact a layer of the powder disposed by the powder deposition module. The system of clause 4, wherein the powder deposition module further comprises a plate moveable relative to the surface and adapted to compact the layer of the powder. The system of clauses 4-5, wherein the press is operatively connected to a blade that is moveable relative to the powder deposition surface and adapted to deposit and compact a layer of the powder disposed by the powder deposition module. The system of clauses 4-6, wherein the press comprises a pressing blade. The system of clauses 4-6, wherein the press comprises a first roller. The system of clause 8, wherein the first roller comprises at least one of a crown shape, a double crown shape, a variable crown shape, and a stepped shape. The system of clauses 8-9, further comprising a second roller in contact with the first roller, the second roller comprising a diameter larger than a diameter of the first roller, the second roller limiting deflection of the first roller. The system of clauses 8-10, wherein the first roller is adapted to rotate in a direction opposite a direction of linear movement of the first roller relative to the powder deposition surface. The system of clauses 8-11, wherein the first roller is adapted to rotate in the same direction as a direction of linear movement of the first roller relative to the powder deposition surface. The system of clauses 8-12, further comprising a scraper adapted to remove powder from the first roller as the first roller rotates. The system of clauses 1-13, wherein the powder deposition module is adapted to apply a pressure of at least 1 psi to a layer of the powder deposited by the powder deposition module. The system of clauses 1-14, wherein the powder deposition module is adapted to apply a pressure of at least 1,000 psi to a layer of the powder deposited by the powder deposition module. The system of clauses 1-15, further comprising a print head adapted to dispense a liquid binder on at least one predetermined region of a layer of the powder disposed by the powder deposition module. The system of clauses 1-16, further comprising an energy source adapted to at least one of sinter and melt at least one predetermined region of a layer of the powder deposited by the powder deposition module. The system of clauses 1-17, further comprising a reservoir communicating with the powder deposition module, wherein the reservoir includes at least two compartments to separately hold different powder. The system of clauses 1-18, further comprising an vibratory unit adapted to vibrate the layer of powder. The system of clauses 1-19, further comprising:

an enclosure enclosing the powder deposition surface, the powder deposition surface being moveable relative to the enclosure; and

a first vibratory unit operatively in communication with the enclosure and adapted to selectively vibrate the layer of powder. The system of clause 20, comprising a plurality of vibratory units including the first vibratory unit, the plurality of vibratory units operatively in communication with the enclosure and adapted to selectively vibrate the layer. An additive manufacturing method comprising:

depositing a layer of powder on a surface; and

compacting the layer of powder; wherein the additive manufacturing method is a powder bed additive

manufacturing method. The method of clause 22, wherein compacting the layer of powder comprises moving a plate into contact with the layer and exerting pressure on the layer of powder with the plate. The method of clauses 22-23, wherein depositing the layer of powder comprises moving a blade in contact with the layer of powder relative to the surface to deposit the layer of powder. The method of clauses 22-24, wherein compacting the layer of powder comprises moving a press into contact with the layer of powder and applying pressure to the layer of powder with the press. The method of clause 25, wherein the press comprises a pressing blade. The method of clause 25-26, wherein the press comprises a first roller and wherein moving the press into contact with the layer of powder comprises rolling the first roller across the layer of powder. The method of clause 27, wherein the first roller comprises at least one of a crown shape, a variable crown shape, and a stepped shape. The method of clauses 27-28, wherein the press further comprises a second roller in contact with the first roller, the second roller having a diameter larger than a diameter of the first roller, the second roller limiting deflection of the first roller. The method of clauses 27-29, wherein compacting the layer of powder further comprises rotating the first roller in a direction opposite a direction of linear movement of the first roller relative to the surface. The method of clauses 27-29, wherein compacting the layer of powder further comprises rotating the first roller in the direction of linear movement of the first roller relative to the surface. The method of clauses 27-31, further comprising removing powder from the first roller utilizing a scraper as the first roller rolls along the layer of powder. The method of clauses 22-32, wherein compacting the layer of powder comprises applying a pressure of at least 1 psi to the layer of powder. The method of clauses 22-33, wherein compacting the layer of powder comprises applying a pressure of at least 1,000 psi to the layer of powder. The method of clauses 22-34, further comprising vibrating the layer of powder. The method of clauses 22-35, wherein the powder comprises at least one of metallic particles, plastic particles, and ceramic particles. The method of clause 36, wherein the ceramic particles comprise at least one of an oxide, a carbide, a nitride, and a boride. The method of clauses 22-37, wherein the 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, tantalum particles, tantalum alloy particles, tungsten particles, and tungsten alloy particles. The method of clauses 22-38, wherein the powder comprises a first powder fraction having a first median particle size and a second powder fraction having a second median particle size, and wherein the ratio of the first median particle size to the second median particle size is in a range of 2: 1 to 20: 1. 40. The method of clause 39, wherein the first median particle size is in a range of 50 nm to 325 pm and the second median particle size is in a range of 1 pm to 65 pm.

41. The method of clauses 22-39, wherein the powder has a span in a range of 1 to 5.

42. The method of clause 41, wherein the powder comprise at least two powder fractions including a first powder fraction having a first median particle size and a second powder fraction having a second median particle size different than the first median particle size.

43. The method of clauses 22-42, wherein the powder includes a first powder fraction having a first general particle shape and a second powder fraction having a second particle shape, and wherein the first particle shape differs from the second particle shape.

44. The method of clauses 22-43, wherein the first particle shape is irregular and the second particle shape is substantially spherical.

45. The method of clauses 22-44, further comprising producing a part preform.

46. The method of clause 45, wherein a porosity of the part preform is less than 50% by volume.

47. The method of clause 45, wherein a porosity of the part preform is less than 45% by volume.

48. The method of clause 45, wherein a porosity of the part preform is less than 30% by volume.

49. The method of clauses 45-48, wherein the part preform is utilized in at least one of the aerospace field, automotive field, transportation field, and building and construction field.

[0089] 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 surface adapted to receive powder; and

a powder deposition module adapted to dispose a layer of powder on the

powder deposition surface and adapted to compact the layer.

2. The system of claim 1, wherein the powder deposition module further comprises a plate moveable relative to the surface and adapted to compact a layer of the powder disposed by the powder deposition module.

3. The system of any one of claims 1-2, wherein the powder deposition module further comprises a blade moveable relative to the powder deposition surface and adapted to deposit and compact a layer of the powder disposed by the powder deposition module.

4. The system of any one of claims 1-3, wherein the powder deposition module further comprises a press moveable relative to the powder deposition surface and adapted to compact a layer of the powder disposed by the powder deposition module.

5. The system of claim 4, wherein the powder deposition module further comprises a plate moveable relative to the surface and adapted to compact the layer of the powder.

6. The system of any one of claims 4-5, wherein the press is operatively connected to a blade that is moveable relative to the powder deposition surface and adapted to deposit and compact a layer of the powder disposed by the powder deposition module.

7. The system of any one of claims 4-6, wherein the press comprises a pressing blade.

8. The system of any one of claims 4-6, wherein the press comprises a first roller.

9. The system of claim 8, wherein the first roller comprises at least one of a crown

shape, a double crown shape, a variable crown shape, and a stepped shape.

10. The system of any one of claims 8-9, further comprising a second roller in contact with the first roller, the second roller comprising a diameter larger than a diameter of the first roller, the second roller limiting deflection of the first roller.

11. The system of any one of claims 8-10, wherein the first roller is adapted to rotate in a direction opposite a direction of linear movement of the first roller relative to the powder deposition surface.

12. The system of any one of claims 8-11, wherein the first roller is adapted to rotate in the same direction as a direction of linear movement of the first roller relative to the powder deposition surface.

13. The system of any one of claims 8-12, further comprising a scraper adapted to remove powder from the first roller as the first roller rotates.

14. The system of any one of claims 1-13, wherein the powder deposition module is adapted to apply a pressure of at least 1 psi to a layer of the powder deposited by the powder deposition module.

15. The system of any one of claims 1-14, wherein the powder deposition module is adapted to apply a pressure of at least 1,000 psi to a layer of the powder deposited by the powder deposition module.

16. The system of any one of claims 1-15, further comprising a print head adapted to dispense a liquid binder on at least one predetermined region of a layer of the powder deposited by the powder deposition module.

17. The system of any one of claims 1-16, further comprising an energy source adapted to at least one of sinter and melt at least one predetermined region of a layer of the powder deposited by the powder deposition module.

18. The system of any one of claims 1-17, further comprising a reservoir communicating with the powder deposition module, wherein the reservoir includes at least two compartments to separately hold different powder.

19. The system of any one of claims 1-18, further comprising an vibratory unit adapted to vibrate the layer of powder.

20. The system of any one of claims 1-19, further comprising:

an enclosure enclosing the powder deposition surface, the powder deposition surface being moveable relative to the enclosure; and a first vibratory unit operatively in communication with the enclosure and adapted to selectively vibrate the layer of powder.

21. The system of claim 20, comprising a plurality of vibratory units including the first vibratory unit, the plurality of vibratory units operatively in communication with the enclosure and adapted to selectively vibrate the layer of powder.

22. An additive manufacturing method comprising:

depositing a layer of powder on a surface; and

compacting the layer of powder;

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

23. The method of claim 22, wherein compacting the layer of powder comprises moving a plate into contact with the layer of powder and exerting pressure on the layer of powder with the plate.

24. The method of any one of claims 22-23, wherein depositing the layer of powder

comprises moving a blade in contact with the layer of powder relative to the surface to deposit the layer of powder.

25. The method of any one of claims 22-24, wherein compacting the layer of powder comprises moving a press into contact with the layer of powder and applying pressure to the layer of powder with the press.

26. The method of claim 25, wherein the press comprises a pressing blade.

27. The method of any one of claims 25-26, wherein the press comprises a first roller and wherein moving the press into contact with the layer of powder comprises rolling the first roller across the layer of powder.

28. The method of claim 27, wherein the first roller comprises at least one of a crown shape, a variable crown shape, and a stepped shape.

29. The method of any one of claims 27-28, wherein the press further comprises a second roller in contact with the first roller, the second roller having a diameter larger than a diameter of the first roller, the second roller limiting deflection of the first roller.

30. The method of any one of claims 27-29, wherein compacting the layer of powder further comprises rotating the first roller in a direction opposite a direction of linear movement of the first roller relative to the surface.

31. The method of any one of claims 27-30, wherein compacting the layer of powder further comprises rotating the first roller in the direction of linear movement of the first roller relative to the surface.

32. The method of any one of claims 27-31, further comprising removing powder from the first roller utilizing a scraper as the first roller rolls along the layer of powder.

33. The method of claim 22, wherein compacting the layer of powder comprises applying a pressure of at least 1 psi to the layer of powder.

34. The method of any one of claims 22-33, wherein compacting the layer of powder comprises applying a pressure of at least 1,000 psi to the layer of powder.

35. The method of any one of claims 22-34, further comprising vibrating the layer of powder.

36. The method of any one of claims 22-35, wherein the powder comprises at least one of metallic particles, plastic particles, and ceramic particles.

37. The method of claim 36, wherein the ceramic particles comprise at least one of an oxide, a carbide, a nitride, and a boride.

38. The method of any one of claims 22-37, wherein the 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, tantalum particles, tantalum alloy particles, tungsten particles, and tungsten alloy particles.

39. The method of any one of claims 22-38, wherein the powder comprises a first powder fraction having a first median particle size and a second powder fraction having a second median particle size, and wherein the ratio of the first median particle size to the second median particle size is in a range of 2: 1 to 20: 1.

40. The method of claim 39, wherein the first median particle size is in a range of 50 nm to 325 pm and the second median particle size is in a range of 1 pm to 65 pm.

41. The method of any one of claims 22-40, wherein the powder has a span in a range of 1 to 5.

42. The method of claim 41, wherein the powder comprises at least two powder fractions including a first powder fraction having a first median particle size and a second powder fraction having a second median particle size different than the first median particle size.

43. The method of any one of claims 22-43, wherein the powder includes a first-powder fraction having a first general particle shape and a second powder fraction having a second particle shape, and wherein the first particle shape differs from the second particle shape.

44. The method of claim 43, wherein the first particle shape is irregular and the second particle shape is substantially spherical.

45. The method of any one of claims 22-44, further comprising producing a part preform.

46. The method of claim 45, wherein a porosity of the part preform is less than 50% by volume.

47. The method of claim 45, wherein a porosity of the part preform is less than 45% by volume.

48. The method of claim 45, wherein the porosity of the part preform is less than 30% by volume.

49. The method of any one of claims 45-48, wherein the part preform is utilized in at least one of the aerospace field, automotive field, transportation field, and building and construction field.