Patent Description:
Generally, in additive manufacturing, powder is spread on a build plate (or on a powder bed formed by a previous layer of powder deposited on the build plate) and then fused together to form a desired part/article of manufacture. Fusing of the particles may be achieved with lasers or any other suitable energy source configured to fuse the powder particles together. Generally, powder is spread on the build plate or powder bed with a doctor blade or roller that pushes a heap of powder from a powder reservoir, located adjacent the build plate, across the build plate or powder bed.

The powder being pushed across the build plate or powder bed by the doctor blade or roller is generally spread over an area of the build plate that is larger than the part being produced. The spreading of the powder results in extra powder being disposed on the build plate that is reclaimed for re-use. The reclamation of the extra powder increases production cycle time, increases production costs, and reduces an amount of powder available for manufacturing the part (e.g., more powder than necessary to manufacture the part must be provided).

In addition to the extra powder on the build plate, the spreading of the powder on the build plate or powder bed with the doctor blade or roller may result in an inconsistent and non-uniform powder distribution across the build plate or powder bed. For example, the doctor blade or roller may drag powder particles across the build plate which may produce streaks in the powder being spread and/or reduce a packing density (e.g., an amount of powder within a predetermined area of the build plate) of the powder on the build plate. Where a roller is used to spread the powder, powder particles may stick to the roller and create craters within the powder bed. The streaks, craters, and/or the decrease in the packing density may increase porosity in the part and/or decrease the adhesion between deposited and fused layers of powder.

<CIT>, in accordance with its abstract, states: A recoating device for an additive manufacturing system includes a plurality of recoater blades which include a first stage and a second stage. The first stage includes a plurality of rows of the plurality of recoater blades and extends in the transverse dimension. The second stage includes a plurality of recoater blades and is configured substantially similar to the first stage of the plurality of recoater blades. The second stage of recoater blades is displaced from the first stage of recoater blades in the vertical dimension.

<CIT>, in accordance with its abstract, states: Additive manufacturing methods and systems using a recoater with in-situ exchangeable recoater blades. Being able to switch out recoater blades in situ, i.e. without stopping the build and opening up the build chamber, is advantageous, especially for larger, more complicated, and/or longer builds. For instance, if a recoater blade becomes damaged, a new one can be readily swapped in. Or if a different material for the object(s) is used during the build, it may be advantageous to switch in a new recoater blade that is made of the new, different material.

<CIT>, in accordance with its abstract, states: An additive manufacturing method including the steps of depositing a first granular construction material as a layer into a build region, and selectively binding regions of the first material together to form bound regions within the layer. Unbound material is then removed from the layer, so as to produce at least one void. A second granular material is then deposited into the build region so as to fill the void(s). Regions of the second material are then selectively bound together within the layer. The second material is different from the first material. The method is achieved by providing an apparatus with means for depositing the first and second granular materials, means for selectively binding regions of a layer, and means for removing unbound material from the build region. Binder may be supplied through an inkjet print head. A smoothing blade may ensure deposited material is of uniform thickness. The removing means may be a suction device.

<CIT>, in accordance with its abstract, states: Providing three-dimensional (3D) objects, 3D printing processes, as well as methods, apparatuses and systems for the production of a 3D object. Methods, apparatuses and systems of the present disclosure may reduce or eliminate the need for auxiliary supports. The present disclosure provides three dimensional (3D) objects printed utilizing the printing processes, methods, apparatuses and systems described herein.

<CIT>, in accordance with its abstract, states: A method for use in dispensing fluids especially particulate matter oil to a surface to be coated, comprising a blade traversing along said surface, whereby the fluid is dispensed in front of said blade on to said surface, whereafter said blade is swept across the dispensed fluid such that it imparts vibrations.

<NPL>, in accordance with its abstract, states: The need to meter and dispense dry powders or mixtures of powders occurs in a wide range of processes and industries. These include the preparation of pharmaceutical products, the mixing of pigments for paints, inks and glazes, the incorporation of processing additives and pigments into polymer processing lines such as extrusion and in solid freeforming processes. This short review identifies the common features of powder handling in these widely different areas and seeks to distinguish and classify the various principles. Examples are given of designs that span a range of industries. This review is stimulated by current developments in the selective laser sintering of powder assemblies; a solid freeforming pathway for polymer, ceramic and metal prototyping and manufacturing. The goal is to find metering and dispensing systems that are effective in providing the spatial arrangement of composition. Dispensing methods that can produce patterns of different powders are sought. Selective laser sintering of powder assemblies can then be extended from a method of rendering shape to one in which both shape and composition are delivered directly into the external world from a computer file.

<CIT>, in accordance with its abstract, states: An apparatus for the layer-by-layer production of three-dimensional objects having a material application unit containing a doctor blade with an edge closest to the construction field having a noncontinuous straight line. In one embodiment the blade may vibrate. A process for layer-by-layer production, wherein the construction field is completely coated with applied powder prior to irradiation is also provided. Three dimensional articles made according to the embodiment are also provided.

<CIT>, in accordance with its abstract, states: A doctor device configured for use in recoating in an operating additive layer manufacturing apparatus is configured, in use, to flex on a first sweep across a surface and remain stiff relative to the flexibility exhibited in the first sweep during a second sweep of the surface.

Accordingly, an additive manufacturing system as defined in claim <NUM> and a method as defined in claim <NUM>, intended to address at least the above-identified concerns, would find utility.

Reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein like reference characters designate the same or similar parts throughout the several views, and wherein:.

Referring to <FIG>, the aspects of the present disclosure provide for an additive manufacturing system <NUM> that includes a build plate <NUM> and one or more of a powder spreading unit <NUM>, a powder dispensing unit <NUM>, and a vibratory compaction system <NUM>.

The powder spreading unit <NUM> includes one or more recoater blades 132A-132n. In one aspect, the powder spreading unit <NUM> may be integrated with one or more of the powder dispensing unit <NUM> and the vibratory compaction system <NUM>. In one aspect, the powder spreading unit <NUM> includes a plurality of recoater blades <NUM> (e.g., including at least two of the recoater blades 132A-132n) that are arranged relative to one another so as to have different spacing and/or angles between the recoater blades 132A-132n. One or more of the recoater blades 132A-132n may include serrated edges (see <FIG>), the serrations having various patterns and orientations, which may effect a uniform spreading of the powder on the build plate <NUM>. The uniform spreading of the powder may provide a consistently dense part (e.g., an increase in packing density compared to non-serrated recoater blades and/or single recoater blades) and reduce the number of streaks and voids in the part (e.g., compared to non-serrated recoater blades and/or single recoater blades).

The plurality (or set) of recoater blades <NUM> are mounted to a base member <NUM> (<FIG>) at predetermined spacings relative to one another. The plurality of recoater blades <NUM> may also have differing gaps <NUM>, <NUM>, <NUM>, <NUM> (see <FIG>) that represent a distance between the build plate <NUM> and the respective recoater blade 132A-132n; where the differing gaps <NUM>, <NUM>, <NUM>, <NUM> correspond with differing gaps 230A, 231A, 232A, 233A (see <FIG>) representing another distance between the powder bed <NUM> and the respective recoater blade 132A-132n) so as to progressively compact the powder <NUM> deposited on the build plate <NUM> or powder bed <NUM>. The recoater blades 132A-132n may be mounted to the base member <NUM> with varying degrees of flexibility. The varying degrees of flexibility may change an angle of the respective recoater blades 132A-132n relative to the build plate <NUM> (e.g., compare <FIG> and <FIG> noting the angle formed between the respective recoater blades 132A-132D, each of the base member <NUM> and the build plate <NUM>) to spread the powder on the build plate <NUM> or powder bed <NUM> so that the powder particles <NUM> (<FIG>) freely move into respective positions on the build plate <NUM> or powder bed <NUM> (e.g., substantially without creating forces on the particles that would drag the particles across the build plate <NUM> or powder bed <NUM>) and fill any gaps that may exist between previously deposited powder particles <NUM>. In one aspect, one of the recoater blades 132A-132n is provided with a compaction shoe (see second portion <NUM> of recoater blade 132D in <FIG>) that may effect compaction of the powder particles <NUM> and a smoothing (e.g., bringing a portion of the powder particles <NUM> forming a surface of the deposited powder or powder bed <NUM> into substantially the same plane <NUM>, <FIG>) of the powder bed <NUM> surface <NUM> (<FIG>).

The vibratory compaction system <NUM> may be integrated with on one or more of the build plate <NUM>, the powder spreading unit <NUM>, and the powder dispensing unit <NUM>. The vibratory compaction system <NUM> is configured to produce one or more of in-plane vibrations <NUM> (<FIG>) and out-of-plane vibrations <NUM> (<FIG> and <FIG>) relative to, for example a powder supporting surface <NUM> (e.g., <FIG>) of the build plate <NUM> or the powder bed <NUM> (<FIG>). The in-plane vibrations <NUM> and/or the out-of-plane vibrations <NUM> may effect relative movement between the powder particles <NUM> (<FIG>) and cause compaction of the powder particles <NUM> through, for example, local rearrangement of the powder particles <NUM>. From being exposed to the in-plane vibrations <NUM> and/or the out-of-plane vibrations <NUM>, the local rearrangement of the powder particles <NUM> may provide an increased packing density (compared to powder particles that have not been exposed to the in-plane vibrations <NUM> and/or the out-of-plane vibrations <NUM>) and to expel possible air pockets that may be trapped within the powder bed <NUM>.

The powder dispensing unit <NUM>, which may be employed with one or more of the powder spreading unit <NUM> and the vibratory compaction system <NUM>, may provide a substantially continuous feed of powder particles <NUM> to the build plate, rather than providing the powder particles in a localized area (e.g., a powder supply <NUM> area, <FIG>, adjacent the build plate <NUM>) and pushing the powder particles across the build plate from the powder localized area. The powder dispensing unit <NUM> includes one or more powder reservoirs 121A-121n that are movable relative to the build plate <NUM>, so as to translate along the powder supporting surface <NUM> (e.g., <FIG>) of the build plate <NUM>. In one aspect, the one or more powder reservoirs 121A-121n are arranged one behind the other relative to a travel direction (see, e.g., travel direction 281A in <FIG>) of the one or more powder reservoirs 121A-121n to provide for multiple layers of powder to be deposited by the powder dispensing unit <NUM> in a common or single pass/translation of the powder dispensing unit <NUM> along the powder supporting surface <NUM>.

In one aspect, where multiple powder reservoirs 121A-121n are employed, the multiple powder reservoirs 121A-121n may store or hold powders having different characteristics (e.g., different physical characteristics and/or different chemical characteristics). For example, the powder held by the multiple powder reservoirs 121A-121n may have different sizes where coarse (e.g., larger) powder particles 1198C (<FIG> and <FIG>) are deposited onto the build plate <NUM> or powder bed <NUM> (<FIG>) prior to fine (e.g., smaller compared to the coarse powder particles 1198C) powder particles 1198F, so that the fine powder particles 1198F may fill in or heal any pores, streaks and/or other defects in the powder bed <NUM> that may cause porosity in the part being produced. Deposition of the fine powder particles 1198F on top of the coarse powder particles 1198C may result in an increased packing density compared to the deposition of only a powder having a single powder particle size. As another example, in addition to or in lieu of having powder particles <NUM> of differing sizes, the multiple powder reservoirs 121A-121n may hold or store powders formed of different materials (e.g., different types of metals <NUM> in a common powder reservoir, a single type of metal <NUM> and polymer(s) <NUM> in a common powder reservoir, a single type of metal <NUM>, polymer(s) <NUM>, ceramics <NUM>, polymer coated metals <NUM>, polymer coated ceramics <NUM>, etc., or a combination of any of the above in a common powder reservoir or in different powder reservoirs) to form in-situ composite parts during the additive manufacturing process, where layers of different materials are stacked one above the other relative to the powder supporting surface <NUM> (<FIG>) of the build plate <NUM>. In one aspect, the multiple powder reservoirs 121A-121n may be arranged side-by-side, in addition to or in lieu of being arranged one behind the other, so as to form in-situ composite parts where the layers of different material are arranged side-by-side relative to the powder supporting surface <NUM> (<FIG>) of the build plate <NUM>.

In another aspect, the one or more powder reservoirs include controllable/variably-sized powder dispensing apertures <NUM> (<FIG> and <FIG>), so that powder held by the respective powder reservoir 121A-121n may be deposited onto the powder supporting surface <NUM> at predetermined areas of the build plate <NUM> that correspond with a geometry of a part being produced. Deposition of the powder in the predetermined areas may provide for reduced cycle times and costs through a near net shape dispensation of the powder (e.g., the powder is dispensed in a manner that resembles the net shape of the part) to create the part rather than blanketing/covering the entire build plate <NUM> with powder irrespective of the geometry of the part being produced. For example, a width of the powder dispensing aperture <NUM> may be adjustable both in size and position relative to a longitudinal centerline <NUM> (<FIG>) of the build plate <NUM>, so as to dispense the powder in the near net shape of the part (see e.g., part <NUM> in <FIG> and <FIG> and the near net shape powder deposition examples <NUM>, <NUM> delineated by dashed line <NUM> and dashed line <NUM>). The size of the powder dispensing apertures <NUM> may be controlled with any suitable controller <NUM> programmed to allow just enough powder to be deposited at predetermined positions of the build plate corresponding to the geometric requirements of the part geometry and other constraints relating to part build-up (e.g., such as unfused powder that is required to support superior layers of powder that are to be fused, such as when the part geometry requires holes or cavities within the part, etc.). Depositing powder in the near net shape may reduce an amount of powder used to form the part, reduce the time required to deposit the powder, reduce the amount of powder reclaimed and associated processing time of the reclaimed powder, and/or reduce cycle time and production costs. Thermal management pertaining to part formation may also be simplified as the excess powder surrounding the part is removed, thereby assisting in the heat transfer (e.g., there is less mass to absorb energy, so that the energy is directed for fusing the powder in a more efficient manner) from the energy source <NUM> (such as a laser, etc.) to the powder.

Referring to <FIG>, as noted above, the additive manufacturing system <NUM> includes a build plate <NUM> and one or more of a powder spreading unit <NUM>, a powder dispensing unit <NUM>, and a vibratory compaction system <NUM>. The build plate <NUM> is coupled to a frame <NUM> of the additive manufacturing system <NUM>; while in other aspects the build plate <NUM> may be or form part of the frame <NUM>. The powder spreading unit <NUM> and the powder dispensing unit <NUM> are movably coupled to the frame <NUM> so as to reciprocate above the build plate <NUM> for spreading and depositing powder on the build plate <NUM>. The powder spreading unit <NUM> and the powder dispensing unit <NUM> are coupled to a reciprocating drive unit <NUM>, so as to be driven in a travel direction <NUM> (<FIG>) across the build plate <NUM> for spreading the powder <NUM> (<FIG>) onto the build plate <NUM>. When the additive manufacturing system includes both the powder spreading unit <NUM> and powder dispensing unit <NUM>, the reciprocating drive unit <NUM> may be configured to drive the powder spreading unit <NUM> and the powder dispensing unit <NUM> in travel direction <NUM> together as a single unit or individually (e.g., the powder spreading unit <NUM> and the powder dispensing unit <NUM> move independent of / relative to one another). In one aspect, the additive manufacturing system <NUM> includes a vibratory compaction system <NUM> coupled to one or more of the build plate <NUM>, the powder dispensing unit <NUM>, and the powder spreading unit <NUM>.

Referring also to <FIG>, the powder <NUM> may be supplied to the powder spreading unit <NUM> by a powder supply <NUM> coupled to the build plate <NUM>. The powder supply <NUM> includes at least one powder reservoir <NUM> which has for its base an elevator <NUM> that moves in direction <NUM> to lift the powder <NUM> from the reservoir <NUM> into a path of the powder spreading unit <NUM>. The powder spreading unit <NUM> is configured to, under impetus of the reciprocating drive unit <NUM>, push powder <NUM> from the at least one powder reservoir <NUM> onto the build plate <NUM>. Any suitable controller <NUM> is provided to control the elevator <NUM> of the at least one powder reservoir <NUM> for lifting the powder <NUM> from the reservoir <NUM>.

In another aspect, where additive manufacturing system <NUM> includes both the powder spreading unit <NUM> and the powder dispensing unit <NUM>, in addition to or in lieu of the powder supply <NUM>, the powder <NUM> may be supplied to the powder spreading unit <NUM> by the powder dispensing unit <NUM> (see, e.g., <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>). In this example, powder <NUM> may be supplied to the powder dispensing unit <NUM> by a powder feed mechanism <NUM>, which may be any suitable powder feed mechanism that feed/supplies powder <NUM> to at least one powder reservoir 121A-121n of the powder dispensing unit <NUM>. Any suitable controller <NUM> is provided to control one or more of the reciprocating drive unit <NUM>, the vibratory compaction system <NUM>, and the dispensation of powder <NUM> from the powder dispensing unit <NUM>.

Referring to <FIG> and <FIG>, the powder spreading unit <NUM> includes a base member <NUM> and the plurality of recoater blades <NUM> that are configured to spread powder <NUM> onto the build plate <NUM>. The plurality of recoater blades <NUM> each form a cantilevered resilient member <NUM> (<FIG>). One or more recoater blade 132A-132n (only four recoater blades 132A-132D are illustrated in <FIG> for exemplary purposes) of the plurality of recoater blades <NUM> includes a first end <NUM> coupled to the base member <NUM> and a second cantilevered end <NUM> extending away from the base member <NUM>. In one aspect, one or more recoater blade 132A-132n of the plurality of recoater blades <NUM> is removably coupled to the base member <NUM> in any suitable manner (such as with clips, snaps, or other removable mechanical fasteners); while in other aspects, the one or more recoater blade 132A-132n of the plurality of recoater blades <NUM> may be formed as a singular unit with the base member <NUM>. The plurality of recoater blades <NUM> are arranged one behind the other in a direction <NUM> extending along a travel direction <NUM> of the powder spreading unit <NUM>.

Each recoater blade 132A-132n of the plurality of recoater blades <NUM> is spaced (see spacings <NUM>, <NUM>, <NUM> in <FIG>), with respect to a travel direction <NUM> of the powder spreading unit <NUM>, from an adjacent recoater blade 132A-132n of the plurality of recoater blades <NUM>. As an example, the spacing <NUM>, <NUM>, <NUM> may be between about <NUM> (about <NUM> inches) to about <NUM> (about <NUM> inches); however, in other aspects the spacing <NUM>, <NUM>, <NUM> may be any suitable spacing. In one aspect, the spacing <NUM>, <NUM>, <NUM> between a first pair of recoater blades of the plurality of recoater blades <NUM> is different than a spacing <NUM>, <NUM>, <NUM> between a second pair of recoater blades of the plurality of recoater blades <NUM>. In one aspect the spacing <NUM>, <NUM>, <NUM> between a first pair of recoater blades of the plurality of recoater blades <NUM> is substantially the same as the spacing <NUM>, <NUM>, <NUM> between a second pair of recoater blades of the plurality of recoater blades <NUM>. It is noted that the first pair of recoater blades includes such pairs as recoater blades 132A, 132B; or recoater blades 132B, 132C; or recoater blades 132C, 132D; or any other suitable pairing of adjacent recoater blades 132A-132n. The second pair of recoater blades includes such pairs as another of recoater blades 132A, 132B; or recoater blades 132B, 132C; or recoater blades 132C, 132D; or any other suitable pairing of adjacent recoater blades 132A-132n.

Referring to <FIG>, <FIG>, and <FIG>, in one aspect, each (or at least one) recoater blade 132A-132n of the plurality of recoater blades <NUM> has respective stiffness, where the respective stiffness depends on an ordinate position (e.g., relative to leading side <NUM>) of a respective recoater blade 132A-132n in the line of recoater blades 132A-132n relative to the travel direction <NUM>. In one aspect, the respective stiffness may be effected by a coupling 135A-135n between a respective recoater blade 132A-132n and the base member <NUM>. For example, one or more recoater blade 132A-132n of the plurality of recoater blades <NUM> is coupled to the base member <NUM> by a coupling 135A-135n that has a first stiffness and another recoater blade 132A-132n of the plurality of recoater blades <NUM> is coupled to the base member <NUM> by another coupling 135A-135n having a second stiffness. In one aspect, the first stiffness is different than the second stiffness; while in other aspects, the first stiffness is substantially the same as the second stiffness. Coupling the recoater blades 132A-132n to the base member <NUM> with the respective coupling 135A-135n may provide a swinging or bending movement of the respective recoater blades 132A-132n, as shown in <FIG> (when the powder spreading unit is moved in the travel direction <NUM> to spread the powder <NUM>), different where the second cantilevered end <NUM> trails (or lags behind - see <FIG>) the first end <NUM>. In another aspect, the respective stiffness of a recoater blade 132A-132n may be effected by a material composition of the recoater blade 132A-132n. For example, one or more recoater blade 132A-132n may be constructed of a resilient material having a predetermined stiffness that allows the one more recoater blade 132A-132n to flex so that the second cantilevered end <NUM> moves relative to the first end <NUM> where, when the powder spreading unit is moved in the travel direction <NUM> to spread the powder <NUM>, the one or more recoater blade 132A-132n bends/flexes so that the second cantilevered end <NUM> moves so as to trail (or lag behind) the first end <NUM> in a manner substantially similar to that shown in <FIG>. The respective stiffness of the recoater blades 132A-132n decreases from a first recoater blade 132A of the plurality of recoater blades <NUM> in the line (e.g., a leading recoater blade relative to the travel direction 281A) to a last recoater blade 132n (shown in <FIG> as recoater blade 132D) of the plurality of recoater blades <NUM> in the line; while in other aspects, the recoater blades 132A-132n may be arranged to have any suitable stiffness relative to the position of the recoater blade 132A-132n in the plurality of recoater blades <NUM>.

Referring to <FIG>, <FIG>, <FIG>, <FIG>, as described above, the plurality of recoater blades <NUM> are arranged one behind the other (e.g., in a line) in the direction <NUM> extending along the travel direction 281A of the powder spreading unit <NUM>. The plurality of recoater blades <NUM> may include any suitable types of recoater blades (e.g., serrated blades, doctor blades without serrations, finishing blades, etc.). A first recoater blade 132A-132n of the plurality of recoater blades <NUM> has a first shape (see e.g., the straight shape of recoater blades 132A-132C, the "bent" shape of recoater blade 132D, the serrated pattern/shape of recoater blade 132A, and the offset serrated pattern/shape of recoater blade 132B) and a second recoater blade 132A-132n of the plurality of recoater blades <NUM> has a second shape (again, see e.g., the straight shape of recoater blades 132A-132C in <FIG> and <FIG>, the "bent" shape of recoater blade 132D in <FIG> and <FIG>, the serrated pattern/shape of recoater blade 132A in <FIG>, and the offset serrated pattern/shape of recoater blade 132B in <FIG>), wherein the first shape and the second shape are different from one another.

At least one of the plurality of recoater blades <NUM> includes serrations <NUM>, <NUM> configured to move powder particles <NUM> of the powder <NUM> (<FIG>) in a direction <NUM> transverse (the direction may have more than one component such as a normal component <NUM>, and a skewing component <NUM>) to the travel direction <NUM> of the powder spreading unit <NUM>. The normal component <NUM> of direction <NUM> may effect a compacting movement of the powder particles <NUM>. The skewing component <NUM> of direction <NUM> may effect, in addition to the compacting movement, driving the powder particles <NUM> along/across the powder bed <NUM> surface <NUM>, formed by previously deposited layers of powder <NUM>, in direction <NUM> so that streaks, pores and/or voids in the powder bed <NUM> surface <NUM> may be filled in. For exemplary purposes, the powder spreading unit <NUM> is illustrated in <FIG> and <FIG> as having at least one serrated blade 132A, 132B, at least one doctor blade 132C without serrations, and at least one finishing blade 132D. The at least one doctor blade 132C is disposed between the at least one serrated blade 132A, 132B and the at least one finishing blade 132D. The finishing blade 132D includes a first portion <NUM> and a second portion <NUM>. The second portion <NUM> of the finishing blade 132D protrudes from the first portion <NUM> at an angle <NUM> and is configured to at least one of compact and smooth (e.g., where, as noted above, smoothing is bringing the portion of the particles forming a surface of the deposited powder into substantially the same plane) the powder <NUM>.

Referring to <FIG>, <FIG>, a first recoater blade (e.g., serrated blade 132A) of the plurality of recoater blades <NUM> has a first serration pattern 300P on an end (e.g., second cantilevered end <NUM>) nearest the powder <NUM> on the powder bed <NUM> / build plate <NUM>. A second recoater blade (e.g., serrated blade 132B) of the plurality of recoater blades <NUM> has a second serration pattern 301P on an end (e.g., second cantilevered end <NUM>) nearest the powder <NUM> on the powder bed <NUM> / build plate <NUM>. The first serration pattern 300P and the second serration pattern 301P are different from one another as will be described below. In one aspect, the first serration pattern 300P and the second serration pattern 301P are offset relative to one another by a predetermined offset distance <NUM> (<FIG>). The offset distance <NUM> is in one aspect, about half of an average of a spacing <NUM> between adjacent serrations <NUM> of the first serration pattern 300P plus a spacing <NUM> between adjacent serrations <NUM> of the second serration pattern 301P; while in other aspects the offset distance <NUM> may be any suitable distance. In one aspect, the spacing <NUM>, <NUM> of the serration patterns 300P, 301P may be substantially the same; while in other aspects, the spacing <NUM> between adjacent serrations <NUM> of the first serration pattern 300P is different than another spacing <NUM> between adjacent serrations <NUM> of the second serration pattern 301P. In one aspect, the spacing <NUM>, <NUM> may be between about five to about twenty-five times the size of a mean powder particle <NUM> size (e.g., for illustrative purposes only, if the powder particles have a mean particle size of about <NUM> micron, then the one or more of a serration slot width <NUM> and a serration prong width <NUM> of recoater blade 132A would be between about <NUM> (about <NUM> inches) and about <NUM> (about <NUM> inches)), or any other suitable spacing. The spacing <NUM>, <NUM> may include the serration slot width <NUM> and the serration prong width <NUM>. In one aspect, the serration slot width <NUM> and the serration prong width <NUM> are substantially the same; while in other aspects the serration slot width <NUM> and the serration prong width <NUM> are different. In one aspect, the serration slot width <NUM> of one or more of the first serration pattern 300P and the second serration pattern 301P is between about one-tenth of a mean size of powder particles <NUM> of the powder <NUM> (<FIG> and <FIG>) and about a largest size (e.g., a largest particle size) of the powder particles <NUM> of the powder <NUM>.

At least one serration <NUM> of the first serration pattern 300P is arranged at a first angle <NUM> relative to the build plate <NUM> (e.g., such as from a reference plane <NUM> that extends orthogonally/normal from the powder supporting surface <NUM> of the build plate <NUM>). At least one serration <NUM> of the second serration pattern 301P is arranged at a second angle <NUM> relative to the build plate <NUM> (e.g., such as from the reference plane <NUM>). In one aspect, the first angle <NUM> is different than the second angle <NUM>; while in other aspects the first angle <NUM> and the second angle <NUM> are substantially the same. As an example, the second angle <NUM> may be larger than the first angle <NUM> (e.g., the angle of the serration pattern of the trailing recoater blade, with respect to, e.g., the travel direction 281A, is greater than the angle of the serration pattern of the leading recoater blade) or vice versa. In one aspect, one or more of the first angle and the second angle is between about +<NUM>° to about -<NUM>° with respect to the reference plane <NUM> extending normal from the powder supporting surface <NUM> of the build plate; in another aspect, one or more of the first angle <NUM> and the second angle <NUM> is between about +<NUM>° to about -<NUM>° with respect to a reference plane <NUM>; and in still another aspect, one or more of the first angle <NUM> and the second angle <NUM> is between about +<NUM>° to about -<NUM>° with respect to the reference plane <NUM>.

As described above and shown in <FIG>, <FIG>, a first recoater blade 132A-132n of the plurality of recoater blades <NUM> is configured to contact the powder <NUM> in a first orientation and a second recoater blade 132A-132n of the plurality of recoater blades <NUM> is configured to contact the powder <NUM> in a second orientation. In one aspect, the first and second orientations include one or more of a deflection angle of the respective recoater blade resulting from the resiliency of the coupling 135A-135n or material stiffness of the cantilevered recoater blades 132A-132n (see <FIG> and <FIG>), a "bent" shape (second portion <NUM>) of the respective recoater blade (see finishing blade 132D), and a shape/offset of a serration pattern 300P, 301P (see <FIG>). In one aspect, the first orientation and the second orientation are different from one another; while in other aspects, the first orientation and the second orientation may be substantially the same.

Referring now to <FIG>, <FIG>, <FIG>, <FIG>, in one aspect, as described above, the additive manufacturing system <NUM> includes the vibratory compaction system <NUM>. The vibratory compaction system <NUM> includes at least one vibration mechanism <NUM> coupled to one or more of the build plate <NUM>, the at least one recoater blade 132A-132n of the plurality of recoater blades <NUM>, and the powder dispensing unit <NUM>. The at least one vibration mechanism <NUM> is coupled to the controller <NUM> where the controller <NUM> is configured to activate and deactivate the at least one vibration mechanism <NUM> to effect compaction of the powder <NUM> deposited on the powder supporting surface <NUM> (e.g., <FIG>) of the build plate <NUM>. The at least one vibration mechanism <NUM> includes one or more of a piezoelectric actuator <NUM>, a transducer <NUM>, or any other suitable vibration generating device that is capable of generating vibratory pulses as described herein.

As can be seen in <FIG>, and <FIG>, the additive manufacturing system includes the build plate <NUM> and the powder spreading unit <NUM>, where the at least one vibration mechanism <NUM> is coupled to a recoater blade 132A of powder spreading unit <NUM>. The powder spreading unit <NUM> is shown as having a single recoater blade 132A for exemplary purposes; while in other aspects the powder spreading unit <NUM> may be substantially similar to powder spreading unit <NUM> where the at least one recoater blade 132A-132n comprises a plurality of recoater blades <NUM> and where the at least one or more vibration mechanism <NUM> is disposed on one or more of the plurality of recoater blades <NUM> (e.g., the at least one vibration mechanism <NUM> is respectively coupled to one or more of the recoater blades 132A-132n). <FIG> illustrates the build plate <NUM> having the at least one vibration mechanism where the at least one vibration mechanism <NUM> is coupled to the build plate <NUM> in any suitable manner. For example, the at least one vibration mechanism <NUM> may be embedded within the powder supporting surface <NUM>, be beneath powder supporting surface <NUM> or be at any other suitable location of the build plate <NUM>. <FIG> illustrates both the build plate <NUM> and the powder spreading unit <NUM> having the at least one vibration mechanism <NUM>. In one aspect, the at least one vibration mechanism <NUM> comprises at least a first vibration mechanism 141A coupled to the build plate <NUM> and a second vibration 141B mechanism, different than the first vibration mechanism 141A, coupled to the at least one recoater blade 132A (see <FIG>).

Referring to <FIG>, the build plate <NUM> has a longitudinal axis <NUM> (see also longitudinal axis <NUM> in <FIG>) and a lateral axis <NUM>. The at least one recoater blade 132A extends at least partially along the lateral axis <NUM> and is configured to move relative to the build plate <NUM> along the longitudinal axis <NUM>, such as in travel direction <NUM>. In one aspect, where the at least one vibration mechanism <NUM> is disposed on the at least one recoater blade 132A, the at least one vibration mechanism <NUM> includes an array of vibration mechanisms <NUM>, coupled to the at least one recoater blade 132A, extending at least in a direction of the lateral axis <NUM>. In one aspect, the array of vibration mechanisms <NUM> may also extend in a direction normal to the powder supporting surface <NUM> of the build plate <NUM> as illustrated in <FIG>. In one aspect, the array of vibration mechanisms <NUM> forms a two dimensional array/grid similar to that shown in <FIG> described below. Referring to <FIG>, where the build plate <NUM> includes the at least one vibration mechanism <NUM>, the at least one vibration mechanism <NUM> includes an array of vibration mechanisms <NUM>, coupled to the build plate <NUM> where the array of vibration mechanisms <NUM> extends along one or more of the longitudinal axis <NUM> and the lateral axis <NUM>.

In one aspect, referring to <FIG>, where the additive manufacturing system <NUM> includes the powder dispensing unit <NUM> (<FIG>), at least one powder reservoir 121A-121n (<FIG>) of the powder dispensing unit <NUM> may include the at least one vibration mechanism <NUM>. The at least one vibration mechanism <NUM> is coupled to the at least one powder reservoir 121A-121n in a manner substantially similar to that described herein with respect to the at least one recoater blade 132A (see <FIG> illustrating the at least one vibration mechanism <NUM> coupled to wall <NUM> of powder reservoir 121B, where the wall <NUM> forms a recoater blade <NUM> substantially similar to any one of recoater blades 132A-132n; see also <FIG> where the at least one vibration mechanism <NUM> may be coupled to wall <NUM>).

Referring to <FIG> and <FIG>, the controller <NUM> is coupled to the at least one vibration mechanism <NUM> and is configured to control activation of the at least one vibration mechanism <NUM> so that vibratory pulses <NUM> (see in-plane vibrations <NUM> and out-of-plane vibrations <NUM>) are induced within the powder <NUM> to effect compaction of the powder <NUM> on the build plate <NUM>. The controller <NUM> is configured to activate and deactivate the at least one vibration mechanism <NUM> in any suitable manner including, but not limited to, one or a combination of the following: in one aspect, the at least one vibration mechanism <NUM> is configured so as to be active while the powder <NUM> is being spread (see <FIG> and <FIG>, as the powder <NUM> is omitted from <FIG> and <FIG> for clarity) by the at least one recoater blade 132A; in another aspect, the at least one vibration mechanism <NUM> is configured so as to be active prior to the powder <NUM> being spread by the at least one recoater blade 132A and/or after the powder <NUM> is spread by the at least one recoater blade 132A, so as to compact a powder that has already been spread across the powder supporting surface <NUM> of the build plate <NUM>; in one aspect, the at least one vibration mechanism <NUM> includes at least a first vibration mechanism 141C and a second vibration mechanism 141D, where the first vibration mechanism 141C and the second vibration mechanism 141D are configured for substantially simultaneous activation (both of the first vibration mechanism 141C and the second vibration mechanism may be disposed on the at least one recoater blade 132A; both of the first vibration mechanism 141C and the second vibration mechanism may be disposed on the build plate <NUM>; or one of the first vibration mechanism 141C and the second vibration mechanism may be disposed on the at least one recoater blade 132A and another of the first vibration mechanism 141C and the second vibration mechanism may be disposed on the build plate <NUM>); in one aspect, the first vibration mechanism 141C and the second vibration mechanism 141D are configured for sequential activation; in another aspect, the first vibration mechanism 141C and the second vibration mechanism 141D are activated at different times. In one aspect, the first vibration mechanism 141C and the second vibration mechanism 141D are deactivated at different times.

The build plate <NUM> defines a powder build plane 510P (that is formed by the powder supporting surface <NUM>) and the at least one vibration mechanism <NUM> is configured to generate, under control of the controller <NUM>, one or more of in-plane vibrations <NUM> in the powder build plane 510P and out-of-plane vibrations <NUM> out of the powder build plane 510P (see <FIG>, and <FIG>). The one or more of the in-plane vibrations <NUM> and the out-of-plane vibrations <NUM> is transmitted to the powder <NUM> (see <FIG>) through a respective one of the build plate <NUM> and the at least one recoater blade 132A. Generation of one or more of the in-plane vibrations <NUM> and the out-of-plane vibrations <NUM> may depend on which of the at least one vibration mechanism <NUM> is active. The at least one vibration mechanism <NUM> is configured, under the control of the controller <NUM>, so as to generate the in-plane vibrations <NUM> and the out-of-plane vibrations <NUM> in an alternating sequence or at the same time.

Referring now to <FIG> and <FIG>, the powder dispensing unit <NUM>, may be used with one or more of the vibratory compaction system <NUM> (see, e.g., <FIG> and <FIG>) and the powder spreading unit <NUM>. See also <FIG>, <FIG> and <FIG> for other various non-limiting exemplary combinations of the powder dispensing unit <NUM> with the vibratory compaction system <NUM> and the powder spreading unit <NUM>; <FIG> for another non-limiting exemplary combination of the powder dispensing unit <NUM> with the vibratory compaction system <NUM>; and <FIG> for another non-limiting exemplary combination of the powder dispensing unit <NUM> with the powder spreading unit <NUM>. The powder dispensing unit includes a base member <NUM> and a powder reservoir 121A coupled to the base member <NUM>. The base member <NUM> may be integral to the powder reservoir 121A or the powder reservoir 121A may be coupled to the base member <NUM> in any suitable manner. The powder reservoir 121A is configured to store a powder where one wall <NUM> of the powder reservoir 121A forms a recoater blade <NUM> substantially similar to any one of recoater blades 132A-132n. In the aspect illustrated in <FIG> and <FIG>, the powder spreading unit <NUM>, <NUM> is coupled to the powder reservoir 121A of the powder dispensing unit <NUM> so that both the powder reservoir 121A and the powder spreading unit <NUM>, <NUM> are moved as a singular unit by the reciprocating drive unit <NUM>, e.g., under control of controller <NUM>. As illustrated in <FIG>, to dispense the powder <NUM>, a powder dispensing closure <NUM> of the powder reservoir 121A is opened under control of the controller <NUM> (or in any other suitable manner) so that the powder <NUM> falls onto and is deposited on the powder supporting surface <NUM> of the build plate <NUM>. As the powder dispensing unit <NUM> moves in the travel direction 281A the powder <NUM> exits the reservoir underneath the wall <NUM> and is smoothed using the recoater blade <NUM> formed by the wall <NUM> and using the powder spreading unit <NUM>, <NUM>. It is noted that the wall <NUM> is spaced from the powder supporting surface <NUM> of the build plate <NUM> (or a previously deposited layer of powder) by distance <NUM> to create a powder dispensing aperture <NUM> for the powder <NUM> to exit the powder reservoir 121A.

In this aspect, the distance <NUM> is larger than a distance <NUM> between wall <NUM> of the powder reservoir 121A and the build plate <NUM> (or powder bed <NUM> - <FIG>) (e.g., the distance <NUM> substantially prevents passage of the powder <NUM> underneath the wall <NUM> so that the powder reservoir deposits the powder <NUM> in a single travel direction 281A); in other aspects, the wall <NUM> may also be spaced from the build plate by the distance <NUM>, so that the powder reservoir deposits the powder <NUM> bi-directionally (e.g., in both travel directions 281A and 281B - see <FIG> and <FIG>). Where the powder reservoir 121A (or a plurality of powder reservoirs disposed one behind the other - See <FIG> and <FIG>) bi-directionally deposit powder <NUM>, powder spreading units <NUM>, <NUM> may be disposed on both walls <NUM>, <NUM> so that there is a powder spreading unit <NUM>, <NUM> trailing the movement of the powder dispensing unit <NUM> in both travel directions 281A, 281B. Where the powder dispensing unit <NUM> is bi-directional, the powder reservoir(s) 121B, 121C (see powder reservoirs 121B, 121C in <FIG> and powder reservoir 121B in <FIG>) disposed on the one side of the powder reservoir 121A are open (e.g., to dispense the respective powder 298A, 298B) while the powder reservoirs 121D, 121E (see powder reservoirs 121D, 121E in <FIG> and powder reservoir 121D in <FIG>) on the other side of the powder reservoir 121A are closed, such as by a respective powder dispensing closure <NUM> (so as not to dispense the respective powder 298A, 298B) and vice versa, depending on the travel direction 281A, 281B.

Referring to <FIG>, <FIG>, <FIG>, and <FIG>, the powder dispensing unit <NUM> is shown illustrated above the build plate <NUM>. In this aspect, the powder dispensing unit <NUM> includes the base member <NUM> (<FIG>, <FIG> and <FIG>) and at least two powder reservoirs 121A-121n coupled to the base member <NUM> (e.g., the base member <NUM> may be integral to at least one of the at least two powder reservoirs 121A-121n or the at least two powder reservoirs 121A-121n are coupled to the base member <NUM> in any suitable manner). The at least two powder reservoirs 121A-121n include, for exemplary purposes, a first powder reservoir 121A and a second powder reservoir 121B; however, in other aspects more than two powder reservoirs may be provided. For example, a third powder reservoir 121C is shown in <FIG> coupled to the first powder reservoir 121A and the second powder reservoir 121B. The first powder reservoir 121A, as described above, is configured to store a first powder <NUM> and deposit the first powder <NUM> onto the build plate <NUM>. The second powder reservoir 121B is configured to store a second powder 298A and deposit the second powder 298A onto the build plate <NUM>. The third powder reservoir 121C (<FIG>) is configured to store a third powder 298B (<FIG>) and deposit the third powder 298B onto the build plate <NUM>.

In <FIG> and <FIG> both the first powder reservoir 121A and the second powder reservoir 121B are coupled to the reciprocating drive unit <NUM> and are configured to move relative to the build plate <NUM>. In <FIG> the first powder reservoir 121A, the second powder reservoir 121B, and the third powder reservoir 121C are coupled to the reciprocating drive unit <NUM> and are configured to move relative to the build plate <NUM>. Referring to <FIG>, an example of powder reservoirs 121A, 121B that move relative to each other, or are separately driven by the reciprocating drive unit <NUM>, are shown. In this aspect, the powder reservoirs 121A, 121B each have a powder spreading unit <NUM>, <NUM> (each having one recoater blade or a plurality of recoater blades <NUM> with or without vibration mechanisms <NUM>) coupled thereto in a manner similar to that described above with respect to <FIG> and <FIG>. In one aspect, the at least two reservoirs 121A-121n that are coupled so as to move as a single unit may also have one or more powder spreading units <NUM>, <NUM> coupled thereto (see, e.g., <FIG> and <FIG>). In one aspect, the plurality of recoater blades <NUM> is positioned so as to trail behind the at least two powder reservoirs 121A-121n in the travel direction <NUM> of the at least two powder reservoirs 121A-121n relative to the build plate <NUM>. In another aspect, at least one of the plurality of recoater blades <NUM> is integral with a wall <NUM>, <NUM>, <NUM> of a respective powder reservoir 121A-121n. The at least one of the plurality of recoater blades integral with the wall <NUM>, <NUM>, <NUM> (as shown in <FIG>, <FIG>, and <FIG>) and/or the disposition of the powder spreading unit between the powder reservoirs 121A, 121B (<FIG>) so that at least one of the plurality of recoater blades <NUM> is disposed between the first powder reservoir 121A and the second powder reservoir 121B (and the third powder reservoir 121C) and another of the plurality of recoater blades <NUM> (which may be integral to the wall <NUM> of the third powder reservoir 121C or part of a powder spreading unit <NUM>) is positioned so as to trail behind the at least two powder reservoirs 121A-121n in a travel direction <NUM> of the at least two powder reservoirs 121A-121n relative to the build plate <NUM>.

Referring to <FIG> and <FIG>, it is noted that where the at least two powder reservoirs 121A-121n are configured to deposit the respective powder <NUM>, 298A, 298B bi-directionally along the travel direction <NUM> (as described above), powder reservoirs 121B, 121C may be disposed on one side of the powder reservoir 121A while powder reservoirs 121D, 121E may be disposed on the opposite side of the powder reservoir 121A (see <FIG> illustrating powder reservoirs 121B and 121D on opposite sides of powder reservoir 121A; and <FIG> where powder reservoirs 121D, 121E are shown in dashed lines). The powder reservoir 121D may be substantially similar to powder reservoir 121B and hold a substantially similar powder 298A to that held by powder reservoir 121B. The powder reservoir 121E may be substantially similar to powder reservoir 121C and hold a substantially similar powder 298B to that held by powder reservoir 121C.

As can be seen in <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>, the first powder reservoir 121A leads the second powder reservoir 121B (and the third powder reservoir 121C) in travel direction 281A, and leads the powder reservoir 121D (and powder reservoir 121E) in the travel direction 281B. The first powder <NUM> is coarser than both the second powder 298A and the third powder 298B (and the second powder 298A is coarser than the third powder 298B). The second powder 298A is deposited on top of the first powder <NUM> by virtue of the powder reservoirs 121B, 121D trailing the powder reservoir 121A in respective travel directions 281A, 281B. The third powder 298B is deposited on top of the second powder 298A by virtue of the powder reservoirs 121C, 121E trailing the powder reservoirs 121B, 121D in respective travel directions 281A, 281B.

In one aspect, the at least two powder reservoirs 121A-121n are configured to move relative to the build plate <NUM> as a single unit (see <FIG>, <FIG>, and <FIG>); while in other aspects, one of the at least two powder reservoirs 121A-121n is configured, such as by the reciprocating drive unit <NUM>, to move relative to the another of the at least two powder reservoirs 121A-121n (see, e.g., <FIG> illustrating the first powder reservoir 121A and the second powder reservoir 121B being individually coupled to the reciprocating drive unit for respective independent movement relative to each other and/or the build plate <NUM>).

Each of the at least two powder reservoirs 121A-121n store a respective powder <NUM>, 298A, 298B. In <FIG>, <FIG>, <FIG>, <FIG>, and <FIG> only two powder reservoirs 121A, 121B and the respective first and second powders <NUM>, 298A are illustrated for clarity; in <FIG> only three powder reservoirs 121A, 121B, 121C and the respective first, second, and third powders <NUM>, 298A, 298B are illustrated for clarity; and in <FIG> only three powder reservoirs 121A, 121B, 121D and the respective first and second powders <NUM>, 298A are illustrated for clarity. In one aspect, powder <NUM>, 298A, 298B stored in one of the at least two powder reservoirs 121A-121n is the same as at least another powder <NUM>, 298A, 298B stored in another of the at least two powder reservoirs 121A-121C. In another aspect, powder stored <NUM>, 298A, 298B in one of the at least two powder reservoirs 121A-121n has a different predetermined characteristic from at least another powder <NUM>, 298A, 298B stored in another of the at least two powder reservoirs 121A-121n. The at least one predetermined characteristic is one or more of a mean size of powder particles <NUM>, <NUM> and a chemical composition of powder particles <NUM>, <NUM>. The chemical composition of a respective one of the first powder <NUM> and the second powder 298A is that of one or more of a polymer, a metal, a ceramic, a polymer coated ceramic, and a polymer coated metal. As non-limiting examples (which may be used alone or in combination), predetermined combinations of characteristics of the powders <NUM>, 298A, 298B stored in the at least two powder reservoirs 121A-121n, include but are not limited to the following: one of the first powder <NUM> and the second powder 298A (and the third powder 298B) is a plastic and another of the first powder <NUM> and the second powder 298A (and the third powder 298B) is a metal; and one of the first powder <NUM> and the second powder 298A (and the third powder 298B) is a first type of metal and another of the first powder <NUM> and the second powder 298A (and the third powder 298B) is a different type of metal.

The at least two powder reservoirs 121A-121n of the additive manufacturing system <NUM> may effect the formation of in-situ alloy creation. For example, as described above, each respective powder <NUM>, 298A, 298B may have a different chemical composition and the at least two powder reservoirs 121A-121n are arranged to deposit the respective powder <NUM>, 298A, 298B so as to form an alloy or composite material <NUM> (<FIG>) in situ the additive manufacturing system <NUM>. One non-limiting example of an alloy that may be produced in situ the additive manufacturing system <NUM> is an aluminum nickel alloy where the first powder reservoir <NUM> includes an aluminum powder and the second powder reservoir includes a nickel powder (other alloys or composites may be produced where the number of different materials in the alloy or composite are stored in respective ones of the at least two powder reservoirs 121A, 121n).

As illustrated in <FIG>, each respective powder <NUM>, 298A, 298B has a different mean powder size (see, e.g., the different sizes of the powder particles <NUM>, <NUM>, <NUM> in <FIG>) and the at least two powder reservoirs 121A-121n are arranged to deposit the respective powder <NUM>, 298A, 298B in an order from a coarsest powder to a finest powder. For example, the at least two powder reservoirs 121A-121n are arranged so that powder 298A, 298B, having a finer powder size, is deposited onto the powder <NUM>, 298A having the coarser powder size (e.g., powder 298A is deposited onto powder <NUM> and powder 298B is deposited onto powder 298A). The first powder <NUM> has a coarser powder size than the second powder 298A (and the second powder 298A has a coarser powder size than the third powder 298B, etc.), where, at one or more predetermined locations on the build plate <NUM>, the first powder <NUM> is deposited onto the build plate <NUM> prior to deposition of the second powder 298A (and, at one or more predetermined locations on the build plate <NUM>, the second powder is deposited onto the build plate <NUM> prior to deposition of the third powder 298B).

As an exemplary arrangement of the at least two powder reservoirs 121A-121n, <FIG> illustrate the at least two powder reservoirs 121A-121n disposed one behind the other along the travel direction <NUM> of the at least two powder reservoirs 121A-121n. Disposing the at least two powder reservoirs 121A-121n one behind the other provides for a smoother powder bed <NUM> surface <NUM> (<FIG>) by depositing powders 298A, 298B having the finer powder size onto powders <NUM>, 298A having the coarser powder size. The at least two powder reservoirs 121A-121n store powders that have progressively smaller sizes (see, e.g., <FIG>, <FIG>, <FIG>, and <FIG>), where the powder particles <NUM> of the first powder <NUM> are larger than the powder particles <NUM> of the second powder 298A, the powder particles <NUM> of the second powder 298A are larger than the powder particles <NUM> of the third powder 298B, and so on so that deposition of finer powders (e.g., powders with smaller sized powder particles compared to other powders dispensed by the at least two powder reservoirs 121A-121n) trails deposition of coarser powders (e.g., powders with larger sized powder particles compared to other powders dispensed by the at least two powder reservoirs 121A-121n), so that the finer powders fill-in some of the pores and voids between the larger sized powder particles.

Referring to <FIG>, <FIG> and <FIG>, the first powder reservoir 121A and the second powder reservoir 121B (and the third powder reservoir 121C where provided) are configured to deposit the first powder <NUM> and the second powder 298A (and the third powder 298B) in a common movement relative to the build plate <NUM> along the travel direction <NUM> of the at least two powder reservoirs 121A-121n. For example, a distance <NUM> between the first powder dispensing aperture <NUM> of the first powder reservoir 121A and the build plate <NUM> is less than another distance <NUM> between a second powder dispensing aperture <NUM> of the second powder reservoir 121B and the build plate <NUM> (see <FIG> and <FIG>). Similarly, the distance <NUM> between the second powder dispensing aperture <NUM> of the second powder reservoir 121B and the build plate <NUM> is less than another distance <NUM> between a third powder dispensing aperture <NUM> of the third powder reservoir 121B and the build plate <NUM> (see <FIG>). The progressively larger distances <NUM>, <NUM>, <NUM> allow for deposition of progressively finer particles onto the powder bed <NUM> / build plate <NUM> in a common pass/movement of the powder dispensing unit <NUM> along the build plate <NUM>. Similarly, where the at least two powder reservoirs 121A-121n are configured to move relative to / separately from one another (as shown in <FIG>), the distance <NUM> between the first powder dispensing aperture <NUM> of the first powder reservoir 121A and the build plate <NUM> is less than another distance <NUM> between a second powder dispensing aperture <NUM> of the second powder reservoir 121B and the build plate <NUM>, so as to allow for deposition of progressively finer particles onto the powder bed <NUM> / build plate <NUM>.

Referring now to <FIG> and <FIG>, an exemplary powder reservoir <NUM> of the powder dispensing unit <NUM> is illustrated (the powder reservoir <NUM> is illustrated in <FIG> without end side walls for clarity). The powder reservoir <NUM> may be substantially similar to the powder reservoirs 121A-121n described above. The powder reservoir <NUM> is illustrated above the build plate <NUM>, where the build plate <NUM> includes a longitudinal axis <NUM> along which the powder reservoir <NUM> moves relative to the build plate <NUM>. In this aspect, the powder reservoir <NUM> includes a powder dispensing aperture <NUM> having a variable size. For example, the powder dispensing aperture <NUM> has a width <NUM> that extends transverse to the longitudinal axis <NUM>. The width <NUM> of the powder dispensing aperture <NUM> is variable, so as to extend (e.g., become larger) or contract (e.g., become smaller) with respect, for example, to a width <NUM> of the powder reservoir <NUM>. The position of the powder dispensing aperture <NUM> may also be adjustable in direction <NUM> relative to a longitudinal centerline <NUM> of the build plate <NUM> (or a centerline <NUM> of the powder reservoir <NUM>, where in some aspects, the centerline <NUM> and the longitudinal centerline <NUM> may be coincident with each other).

Still referring to <FIG> and <FIG>, the controller <NUM> is coupled to the powder reservoir <NUM> and is configured to effect a variable sizing of the powder dispensing aperture <NUM>. The variable sizing of the powder dispensing aperture <NUM> may be effected by the controller <NUM> as the powder reservoir <NUM> moves relative to the build plate <NUM>. The controller <NUM> is configured to variably size the powder dispensing aperture <NUM>, such as relative to the longitudinal centerline <NUM>, based on the structure (part) <NUM> produced by the additive manufacturing system <NUM> so as to deposit the powder <NUM> in the near net shape. The controller <NUM> is configured to variably size the width <NUM>, so that the powder dispensing aperture <NUM> is offset (see <FIG>) relative to the longitudinal centerline <NUM> of the build plate <NUM>.

The powder dispensing aperture <NUM> having the variable size effects deposition of powder <NUM> on less than an entirety of the build plate <NUM>. In one aspect, a structure <NUM> produced by the additive manufacturing system <NUM> is smaller than the build plate <NUM> and more than <NUM>% of the powder <NUM> deposited on the build plate <NUM> is used to produce the structure <NUM>. In another aspect, structure <NUM> produced by the additive manufacturing system <NUM> is smaller than the build plate <NUM> and more than <NUM>% of the powder <NUM> deposited on the build plate <NUM> is used to produce the structure <NUM>. In still another aspect, structure <NUM> produced by the additive manufacturing system <NUM> is smaller than the build plate <NUM> and more than <NUM>% of the powder <NUM> deposited on the build plate <NUM> is used to produce the structure <NUM>. For example, <FIG> illustrates the structure <NUM> disposed on the build plate <NUM>. <FIG> illustrates exemplary near net shape powder deposition patterns <NUM>, <NUM> that may be deposited by the powder reservoir <NUM> to manufacture the structure <NUM>. The powder deposition pattern <NUM> is denoted by dashed line <NUM> and conforms to a rectangle defined by a length and width of the structure <NUM>. The powder deposition pattern <NUM> is denoted by the dashed line <NUM> and conforms to the detailed contours of the structure <NUM>. The near net shape powder deposition provided by the powder reservoir <NUM> preserves the powder <NUM> for the production of the structure <NUM> rather than spreading the powder on portions of the build plate <NUM> that are not used to support the structure <NUM>.

Referring also to <FIG>, an example of powder deposition savings (e.g., in both the amount of powder used and cycle time) using the powder reservoir <NUM> will be described when compared to a typical powder spreading using only a recoater blade that spreads powder over substantially the entirety of the build plate. In this example, the dimensions provided are exemplary only. The build plate <NUM> has a width <NUM> of about <NUM> (about <NUM> inches) and a length <NUM> of about <NUM> (about <NUM> inches). The structure <NUM> being produced is, for example, a frustum of a pyramid having a base with a width <NUM> of about <NUM> (about <NUM> inches) and a length <NUM> of about <NUM> (about <NUM> inches). The structure <NUM> has a top having a width <NUM> of about <NUM> (about <NUM> inches) and a length <NUM> of about <NUM> (about <NUM> inches). The structure has a height <NUM> of about <NUM> (about <NUM> inches). An amount of powder typically required for spreading on the build plate <NUM>, such as with a recoater blade alone would be about <NUM><NUM> (about <NUM> in<NUM>) where the powder is spread substantially over the entirety of the powder supporting surface <NUM> of the build plate <NUM>. An amount of powder required for depositing on the build plate using the powder reservoir <NUM> having the variable width <NUM> powder dispensing aperture <NUM> would be about <NUM><NUM> (about <NUM> in<NUM>) which is about a <NUM>% powder savings compared to spreading the powder over the entirety of the powder supporting surface <NUM> of the build plate <NUM>. The savings in powder deposition reduces the cycle time (e.g., powder reclamation time) of producing the structure <NUM>. The savings in powder deposition also preserves the powder for use in manufacturing the structure <NUM>, so that larger parts may be produced without having to replenish the powder supply, and/or provides for smaller powder reservoirs to be employed.

Referring to <FIG>, <FIG>, <FIG> the powder dispensing aperture <NUM> of the powder reservoir <NUM> may be at least partially closed by the powder dispensing closure <NUM>. The powder dispensing closure <NUM> includes at least one shutter <NUM> adjacent the powder dispensing aperture <NUM>. At least one stepper motor <NUM>, <NUM> is coupled to the at least one shutter <NUM> of the powder dispensing aperture <NUM> to effect variable sizing of the powder dispensing aperture <NUM> and to define the variable size of the powder dispensing aperture <NUM>. As described above, the powder dispensing closure <NUM>, and the at least one shutter <NUM>, is disposed, adjacent the build plate <NUM>, at a bottom of the powder reservoir <NUM> so as to stop passage of powder <NUM> passing through the powder dispensing aperture <NUM>.

Referring to <FIG>, in one aspect, the at least one shutter <NUM> includes at least one plate <NUM>, <NUM>. For example, the build plate <NUM> includes the longitudinal axis <NUM> along which the powder reservoir <NUM> moves relative to the build plate <NUM> (the powder reservoir <NUM> is illustrated in <FIG> without the end side walls for clarity). The powder reservoir <NUM> has the width <NUM> that extends transverse to the longitudinal axis <NUM>. The powder reservoir <NUM> comprises opposing shutters 1900A, 1900B, where at least one stepper motor <NUM>, <NUM> is coupled to the opposing shutters 1900A, 1900B so as to, at least, variably size the powder dispensing aperture <NUM> along the width <NUM>. The at least one stepper motor <NUM>, <NUM> may also be coupled to the opposing shutters 1900A, 1900B so as to variably position the powder dispensing aperture <NUM> along the width <NUM> so that the powder dispensing aperture is offset from the centerline <NUM>. For example, opposing shutter 1900A includes plate <NUM> that is coupled to the stepper motor <NUM>. The plate <NUM> is movably coupled to the bottom of the powder reservoir <NUM> so as to move in direction <NUM> transverse to the centerline <NUM>. Opposing shutter 1900B includes plate <NUM> that is coupled to the stepper motor <NUM>. The plate <NUM> is movably coupled to the bottom of the powder reservoir <NUM> so as to move in direction <NUM> transverse to the centerline <NUM>. The stepper motors <NUM>, <NUM> are coupled to the controller <NUM> so as to, under control of the controller <NUM>, move the respective plate <NUM>, <NUM> in direction <NUM> where the plates are one or more of moved together in unison in the same direction (e.g., to offset the powder dispensing aperture <NUM> from the centerline <NUM>) and moved in opposite directions at the same time or different times (e.g., to increase or decrease the width <NUM> of the powder dispensing aperture <NUM>).

Referring to <FIG>, <FIG>, in one aspect, the at least one shutter <NUM> includes at least one spiral spring <NUM>, <NUM>. The at least one spiral spring <NUM>, <NUM> includes a first spiral spring <NUM> and a second spiral spring <NUM> configured to wind and unwind in opposing directions. Each of the first spiral spring <NUM> and the second spiral spring <NUM> has respective apertures <NUM> (see, e.g., <FIG>) that, at least in part, define the powder dispensing aperture <NUM>. For example, the build plate <NUM> includes the longitudinal axis <NUM> along which the powder reservoir <NUM> moves relative to the build plate <NUM> (the powder reservoir <NUM> is illustrated in <FIG> without the end side walls for clarity). The powder reservoir <NUM> has the width <NUM> that extends transverse to the longitudinal axis <NUM>. The powder reservoir <NUM> comprises opposing shutters 1900A, 1900B, where at least one stepper motor <NUM>, <NUM> is coupled to the opposing shutters 1900A, 1900B so as to, at least, variably size the powder dispensing aperture <NUM> along the width <NUM>. The at least one stepper motor <NUM>, <NUM> may also be coupled to the opposing shutters 1900A, 1900B so as to variably position the powder dispensing aperture <NUM> along the width <NUM> so that the powder dispensing aperture is offset from the centerline <NUM>. For example, opposing shutter 1900A includes spiral spring <NUM> that is coupled to the stepper motor <NUM>. The spiral spring <NUM> includes a first end <NUM> and a second end <NUM>. The second end <NUM> defines a first and second tong <NUM>, <NUM> so as to form a slot <NUM> having a root <NUM> extending between the first and second tong <NUM>, <NUM>. The root <NUM> defines a movable end of the powder dispensing aperture <NUM>.

The spiral spring <NUM> is coiled to at least one shaft <NUM>, <NUM> mounted to the at least one powder reservoir <NUM>. At least one stepper motor <NUM>, <NUM> is coupled to the spiral spring <NUM> to effect variable sizing of the powder dispensing aperture <NUM>. For example, the first end <NUM> of the spiral spring <NUM> may be wound around a shaft <NUM> (<FIG>) so that as the spiral spring <NUM> is pulled from the shaft <NUM> the spiral spring <NUM> is biased to recoil around the shaft <NUM> in direction <NUM>. The second end <NUM> of the spiral spring <NUM> is wound around shaft <NUM>. The shaft <NUM> may be driven by the stepper motor <NUM> so as to pull or uncoil the spiral spring <NUM> from the shaft <NUM> (or to allow recoiling of the spiral spring <NUM> on the shaft <NUM>) so as to move the root <NUM> in direction <NUM>. The spiral spring <NUM> is movably coupled to the bottom of the powder reservoir <NUM> so that the root <NUM> moves in direction <NUM> transverse to the centerline <NUM>. Opposing shutter 1900B includes spiral spring <NUM> that is coupled to the stepper motor <NUM>. The spiral spring <NUM> is substantially similar to spiral spring <NUM> and is movably coupled to the bottom of the powder reservoir <NUM> so that the root <NUM> of spiral spring <NUM> moves in direction <NUM> transverse to the centerline <NUM> under the impetus of the stepper motor <NUM>. The stepper motors <NUM>, <NUM> are coupled to the controller <NUM> so as to, under control of the controller <NUM>, move the respective roots <NUM> of the spiral springs <NUM>, <NUM> in direction <NUM> where the roots <NUM> are one or more of moved together in unison in the same direction (e.g., to offset the powder dispensing aperture <NUM> from the centerline <NUM>) and moved in opposite directions at the same time or different times (e.g., to increase or decrease the width <NUM> of the powder dispensing aperture <NUM>).

Referring to <FIG>, <FIG>, in one aspect, the at least one shutter <NUM> includes at least one flexible sheet <NUM>, <NUM>. For example, the build plate <NUM> includes the longitudinal axis <NUM> along which the powder reservoir <NUM> moves relative to the build plate <NUM> (the powder reservoir <NUM> is illustrated in <FIG> without the end side walls for clarity). The powder reservoir <NUM> has the width <NUM> that extends transverse to the longitudinal axis <NUM>. The powder reservoir <NUM> comprises opposing shutters 1900A, 1900B, where at least one stepper motor <NUM>, <NUM> is coupled to the opposing shutters 1900A, 1900B so as to, at least, variably size the powder dispensing aperture <NUM> along the width <NUM>. The at least one stepper motor <NUM>, <NUM> may also be coupled to the opposing shutters 1900A, 1900B so as to variably position the powder dispensing aperture <NUM> along the width <NUM> so that the powder dispensing aperture is offset from the centerline <NUM>. For example, opposing shutter 1900A includes flexible sheet <NUM> that is coupled to the stepper motor <NUM>. The flexible sheet <NUM> includes a first end <NUM> and a second end <NUM>. The second end <NUM> defines a first and second tong <NUM>, <NUM> so as to form a slot <NUM> having a root <NUM> extending between the first and second tong <NUM>, <NUM> so as to form an aperture <NUM> that at least in part defines the powder dispensing aperture <NUM>. The root <NUM> defines a movable end of the powder dispensing aperture <NUM>. The flexible sheet <NUM> is movably coupled to the bottom of the powder reservoir <NUM> so that the first end <NUM> and the second end <NUM> of the flexible sheet <NUM> bend so as to travel along lateral ends 121S1, 121S2 of the powder reservoir <NUM>. The flexible sheet <NUM> may be driven by the stepper motor <NUM> so as to move the root <NUM> in direction <NUM>. Opposing shutter 1900B includes flexible sheet <NUM> that is coupled to the stepper motor <NUM>. The flexible sheet <NUM> is substantially similar to flexible sheet <NUM> and is movably coupled to the bottom of the powder reservoir <NUM> so that the root <NUM> of flexible sheet <NUM> moves in direction <NUM> transverse to the centerline <NUM> under the impetus of the stepper motor <NUM>. The stepper motors <NUM>, <NUM> are coupled to the controller <NUM> so as to, under control of the controller <NUM>, move the respective roots <NUM> of the flexible sheets <NUM>, <NUM> in direction <NUM> where the roots <NUM> are one or more of moved together in unison in the same direction (e.g., to offset the powder dispensing aperture <NUM> from the centerline <NUM>) and moved in opposite directions at the same time or different times (e.g., to increase or decrease the width <NUM> of the powder dispensing aperture <NUM>).

Referring to <FIG>, in a manner similar to that described above, the additive manufacturing system <NUM> may include at least two powder reservoirs 121A-121n (only powder reservoirs 121A, 121B are shown for illustrative purposes) having the variably sized powder dispensing aperture <NUM>. In the manner described above, in one aspect, each of the at least two powder reservoirs 121A, 121B may be coupled to the reciprocating drive unit <NUM> so as to be separately moved, in travel direction <NUM>, relative another of the at least two powder reservoirs 121A, 121B. In the manner described above, in another aspect, the at least two powder reservoirs 121A, 121B may be coupled to the reciprocating drive unit <NUM> so as to move in travel direction <NUM> as a single unit.

Referring to <FIG>, at least one of the powder reservoirs <NUM> of the additive manufacturing system <NUM> may be configured to deposit one or more powders <NUM>, 298A in a side by side arrangement on the powder supporting surface <NUM> of the build plate <NUM>. For example, the build plate <NUM> includes a longitudinal axis <NUM> along which the at least one powder reservoir <NUM> moves relative to the build plate <NUM>. The at least one powder reservoir <NUM> has a width <NUM> that extends transverse to the longitudinal axis <NUM>. The at least one powder reservoir <NUM> includes a plurality of powder storage compartments <NUM>, <NUM> arranged side by side along the width <NUM> so as to dispense powder <NUM>, 298A from the respective powder storage compartments <NUM>, <NUM> onto the build plate <NUM> in a side by side arrangement transverse to the longitudinal axis <NUM>. As described above, deposition of the powders <NUM>, 298A provides for the in situ formation of alloys or composites.

The powder reservoir of <FIG> may include a diaphragm <NUM> extending between adjacent powder storage compartments <NUM>, <NUM>. The diaphragm <NUM> is coupled to the powder dispensing aperture <NUM> (e.g., such as to the plates <NUM>, <NUM>, the spiral springs <NUM>, <NUM>, or flexible sheets <NUM>, <NUM>) so that a portion of the powder dispensing aperture <NUM> dispenses the first powder <NUM> from a first powder storage compartment <NUM> of the plurality of powder storage compartments <NUM>, <NUM> and another portion of the powder dispensing aperture <NUM> dispenses the second powder 298A from a second powder storage compartment <NUM> of the plurality of powder storage compartments <NUM>, <NUM>. In one aspect, the powder dispensing aperture <NUM> is formed, at least in part, by at least one shutter 1900A, 1900B that is variably positioned along the width <NUM> of the powder reservoir <NUM>. The diaphragm <NUM> is coupled to the at least one shutter 1900A, 1900B so that one end <NUM> of the diaphragm moves with the at least one shutter 1900A, 1900B along the width <NUM>. In one aspect, the powder dispensing aperture may have a fixed width <NUM> where the diaphragm <NUM> is coupled to both opposing shutters 1900A, 1900B. In another aspect, the diaphragm may be coupled to a diaphragm positioning member <NUM> (shown in dashed lines) that is substantially similar to one of the plates <NUM>, <NUM>, the spiral springs <NUM>, <NUM>, or flexible sheets <NUM>, <NUM> so that an end <NUM> of the diaphragm <NUM> adjacent the powder dispensing aperture <NUM> is moves (e.g., by stepper motor(s) coupled to and under control of the controller <NUM>) relative to the opposing shutters 1900A, 1900B so that the width <NUM> of the powder dispensing aperture <NUM> may be variable as described herein.

Referring now to <FIG>, <FIG> exemplary methods <NUM>, <NUM>, <NUM>, <NUM> for spreading and/or dispensing powder(s) <NUM>, 298A, 298B on the build plate <NUM> in the additive manufacturing system <NUM> will be described. The exemplary methods may be employed individually or in any suitable combination thereof.

Referring to <FIG> and <FIG>, the method <NUM> includes depositing powder <NUM>, 298A, 298B on the build plate <NUM> (<FIG>, Block <NUM>). In one aspect depositing powder <NUM>, 298A, 298B on the build plate <NUM> includes pushing the powder <NUM>, 298A, 298B from the at least one powder reservoir <NUM> with the powder spreading unit <NUM>. In another aspect, depositing the powder <NUM>, 298A, 298B on the build plate <NUM> with at least one powder reservoir 121A-121n of the powder spreading unit <NUM> (in this aspect, the powder dispensing unit <NUM> is coupled to the powder spreading unit <NUM> - see, e.g., <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>), where the powder reservoir 121A-121n reciprocates in the travel direction <NUM> across the build plate <NUM>, and where the powder <NUM>, 298A, 298B deposited by the at least one powder reservoir 121A-121n is spread with the plurality of recoater blades <NUM> coupled to the at least one powder reservoir. In one aspect, depositing the powder <NUM>, 298A, 298B includes depositing, with at least one of a plurality of powder reservoirs 121A-121n, powder particles <NUM>, <NUM>, <NUM> (see <FIG>, <FIG>, and <FIG>) having a different size than powder particles <NUM>, <NUM>, <NUM> deposited by another powder reservoir of the plurality of powder reservoirs 121A-121n. In one aspect, depositing the powder <NUM>, 298A, 298B includes varying a size of a powder dispensing aperture <NUM> (<FIG>) of at least one powder reservoir 121A-121n.

The method <NUM> also includes spreading the powder <NUM>, 298A, 298B on the build plate <NUM> (<FIG>, Block <NUM>) with a powder spreading unit <NUM> having a plurality of recoater blades <NUM>. For example, powder spreading unit <NUM> is driven in a travel direction <NUM> across the build plate <NUM>, with a reciprocating drive unit <NUM>, so as to spread the powder onto the build plate <NUM>. In one aspect, spreading the powder <NUM>, 298A, 298B includes contacting the powder <NUM>, 298A, 298B with a first recoater blade (e.g., one of recoater blades 132A-132D) of the plurality of recoater blades <NUM> in a first orientation, and contacting the powder with a second recoater blade (e.g., another of recoater blades 132A-132D) of the plurality of recoater blades <NUM> in a second orientation, wherein the first orientation and the second orientation are different from one another as described above. Spreading the powder <NUM>, 298A, 298B may also include compacting and smoothing the powder <NUM>, 298A, 298B with at least one finishing blade 132D of the plurality of recoater blades <NUM>, wherein the plurality of recoater blades <NUM> are arranged one behind the other in a direction extending along the travel direction <NUM> of the powder spreading unit <NUM>, and the plurality of recoater blades <NUM> includes at least one serrated blade 132A, 132B, at least one doctor blade 132C, and the at least one finishing blade 132D. In one aspect, spreading the powder <NUM>, 298A, 298B on the build plate <NUM> includes moving powder particles <NUM>, <NUM>, <NUM> (see <FIG>, <FIG>, and <FIG>) of the powder <NUM>, 298A, 298B in a direction transverse to the travel direction <NUM> of the powder spreading unit <NUM> with serrations <NUM> of at least one of the plurality of recoater blades <NUM>. Spreading the powder <NUM>, 298A, 298B may also include compacting the powder <NUM>, 298A, 298B spread on the build plate <NUM> with at least one vibration mechanism <NUM> disposed on at least one recoater blade 132A-132n of the plurality of recoater blades <NUM> and/or compacting the powder <NUM>, 298A, 298B spread on the build plate <NUM> with at least one vibration mechanism <NUM> disposed on the build plate <NUM>.

Referring to <FIG>, <FIG>, <FIG>, and <FIG>, the method <NUM> includes storing powder <NUM>, 298A, 298B in at least two powder reservoirs 121A-121n (<FIG>, Block <NUM>), where a first powder reservoir 121A stores a first powder <NUM> and moves relative to the build plate <NUM>, and a second powder reservoir 121B stores a second powder 298A and moves relative to the build plate <NUM>. In one aspect, the first powder <NUM> has at least one predetermined characteristic that is different than that of the second powder 298A. In one aspect, powder <NUM>, 298A, 298B stored in one of the at least two powder reservoirs 121A-121n is the same as at least another powder <NUM>, 298A, 298B stored in another of the at least two powder reservoirs 121A-121n. In one aspect, each of the at least two powder reservoirs 121A-121n stores a respective powder <NUM>, 298A, 298B, where each respective powder <NUM>, 298A, 298B is different than another respective powder <NUM>, 298A, 298B stored in another of the at least two powder reservoirs 121A-121n, and each respective powder <NUM>, 298A, 298B has a different mean powder particle size. In one aspect, storing powder <NUM>, 298A, 298B includes storing the powders <NUM>, 298A, 298B that have progressively smaller sizes in the at least two powder reservoirs 121A-121n where the at least two powder reservoirs 121A-121n are disposed one behind the other along the travel direction <NUM> of the at least two powder reservoirs 121A-121n.

The method <NUM> also includes depositing, from a respective one of the first powder reservoir 121A and the second powder reservoir 121B, the first powder <NUM> and the second powder 298A onto the build plate <NUM> (<FIG>, Block <NUM>). In the method <NUM> the first powder <NUM> is deposited at one or more predetermined locations on the build plate <NUM> prior to deposition of the second powder 298A, 298B where the first powder <NUM> has a coarser powder particle size than the second powder 298A, 298B. In one aspect, depositing the first and second powder <NUM>, 298A includes moving the at least two powder reservoirs 121A-121n relative to the build plate <NUM> as a single unit. In one aspect, depositing the first and second powder <NUM>, 298A includes moving one of the first powder reservoir 121A and the second powder reservoir 121B relative to the other of the first powder reservoir 121A and the second powder reservoir 121B. In one aspect, depositing the powder includes depositing finer powder particles 1198F on top of coarser powder particles 1198C so that deposition of the finer powder particles 1198F trails deposition of the coarser powder particles 1198C. In one aspect, a respective powder <NUM>, 298A, 298B is deposited from the at least two powder reservoirs 121A-121n in an order from a coarsest powder to a finest powder. In one aspect, the respective powder <NUM>, 298A, 298B is bi-directionally deposited from the at least two powder reservoirs 121A-121n along the travel direction <NUM> of the at least two powder reservoirs 121A-121n. In one aspect, the second powder 298A and the third powder 298B are deposited on top of the first powder <NUM> (as described above), where the first powder <NUM> is coarser than the second powder 298A and the third powder 298B. In one aspect, depositing the powder <NUM>, 298A, 298B includes compacting the first powder <NUM> and the second powder 298A deposited on the build plate <NUM> with at least one vibration mechanism <NUM> coupled to one or more of the at least two powder reservoirs 121A-121n and the build plate <NUM>. In one aspect, a size of a powder dispensing aperture <NUM> (<FIG>) of one or more of the at least two powder reservoirs 121A-121n is varied during dispensing of a respective powder <NUM>, 298A, 298B. In one aspect, depositing the powder includes one or more of smoothing and compacting a the first powder <NUM> and the second powder 298A deposited on the build plate <NUM> with a plurality of recoater blades 132A-132n coupled to one or more of the at least two powder reservoirs 121A-121n.

The method <NUM> may also include forming, in situ the additive manufacturing system <NUM>, an alloy or composite material (<FIG>, Block <NUM>) wherein each respective powder <NUM>, 298A, 298B of the at least two powder reservoirs 121A-121n has a different chemical composition. The method <NUM> may also include supplying powder <NUM>, 298A, 298B with a powder feed mechanism <NUM> to a respective powder reservoir 121A-121n (<FIG>, Block <NUM>).

Referring to <FIG>, <FIG>, and <FIG>, the method <NUM> includes storing powder <NUM>, 298A, 298B in at least one powder reservoir 121A-121n (<FIG>, Block <NUM>). The method <NUM> also includes varying a size of the powder dispensing aperture <NUM> of the at least one powder reservoir 121A-121n when depositing powder <NUM>, 298A, 298B onto the build plate <NUM> (<FIG>, Block <NUM>). The width <NUM> of the powder dispensing aperture <NUM> is varied with the controller <NUM> coupled to the at least one powder reservoir. In one aspect, the width <NUM> of the powder dispensing aperture <NUM> is varied with the controller <NUM> so that the powder dispensing aperture <NUM> is offset relative to the longitudinal centerline <NUM> of the build plate <NUM>. In one aspect, the width <NUM> of the powder dispensing aperture <NUM> is varied with the controller <NUM> relative to the longitudinal centerline <NUM> of the build plate <NUM> based on a structure <NUM> produced by the additive manufacturing system <NUM>. The width <NUM> is varied as the at least one powder reservoir 121A-121n moves relative to the build plate <NUM>. Varying the size of the powder dispensing aperture <NUM> includes depositing powder <NUM>, 298A, 298B on less than an entirety of the build plate <NUM>. The size of the powder dispensing aperture <NUM> may be varied with at least one stepper motor <NUM>, <NUM> that drives at least one shutter 1900A, 1900B.

Referring to <FIG>, <FIG>, and <FIG>, the method <NUM> includes controlling, with the controller <NUM>, actuation of at least one vibration mechanism <NUM> coupled to one or more of the build plate <NUM> and at least one recoater blade 132A-132n (<FIG>, Block <NUM>). The method <NUM> also includes inducing vibratory pulses <NUM> within the powder <NUM>, 298A, 298B with the at least one vibration mechanism <NUM> to effect compaction of the powder <NUM>, 298A, 298B on the build plate <NUM> (<FIG>, Block <NUM>). In one aspect, the at least one vibration mechanism <NUM> is activated while the powder <NUM>, 298A, 298B is being spread by at least one recoater blade 132A-132n. In one aspect, the at least one vibration mechanism <NUM> is activated prior to the powder <NUM>, 298A, 298B being spread by the at least one recoater blade 132A-132n and/or after the powder <NUM>, 298A, 298B is spread by the at least one recoater blade 132A-132n. In one aspect, the at least one vibration mechanism <NUM> includes at least a first vibration mechanism 141A-141D and a second vibration mechanism 141A-141D, and the first vibration mechanism 141A-141D and the second vibration mechanism 141A-141D are substantially simultaneously activated with the controller <NUM>. In one aspect, the first vibration mechanism 141A-141D and the second vibration mechanism 141A-141D are sequentially activated with the controller <NUM>. In one aspect, the first vibration mechanism 141A-141D and the second vibration mechanism 141A-141D are activated at different times with the controller <NUM>. In one aspect, the first vibration mechanism 141A-141D and the second vibration mechanism 141A-141D are deactivated at different times with the controller <NUM>. In one aspect, the build plate <NUM> defines a powder build plane 510P and the at least one vibration mechanism <NUM> is activated by the controller <NUM> to generate one or more of in-plane vibrations <NUM> in the powder build plane 510P and out-of-plane vibrations <NUM> out of the powder build plane 510P. The one or more of the in-plane vibrations <NUM> and the out-of-plane vibrations <NUM> are transmitted to the powder <NUM>, 298A, 298B through a respective one of the build plate <NUM> and the at least one recoater blade 132A-132n. Generation of one or more of the in-plane vibrations <NUM> and the out-of-plane vibrations <NUM> depends on which of the at least one vibration mechanism <NUM> is active. In one aspect, the controller <NUM> activates the at least one vibration mechanism <NUM> so as to generate the in-plane vibrations <NUM> and the out-of-plane vibrations <NUM> in an alternating sequence. In one aspect the at least one vibration mechanism <NUM> is moved along the longitudinal axis <NUM> with the at least one recoater blade 132A-132n. The where the at least one vibration mechanism <NUM> is the vibratory pulses <NUM> generated by the at least one vibration mechanism <NUM> follow movement of the at least one recoater blade 132A-132n along the longitudinal axis <NUM>.

In the figures, referred to above, solid lines, if any, connecting various elements and/or components may represent mechanical, electrical, fluid, optical, electromagnetic, wireless and other couplings and/or combinations thereof. As used herein, "coupled" means associated directly as well as indirectly. For example, a member A may be directly associated with a member B, or may be indirectly associated therewith, e.g., via another member C. It will be understood that not all relationships among the various disclosed elements are necessarily represented. Accordingly, couplings other than those depicted in the drawings may also exist. Dashed lines, if any, connecting blocks designating the various elements and/or components represent couplings similar in function and purpose to those represented by solid lines; however, couplings represented by the dashed lines may either be selectively provided or may relate to alternative examples of the present disclosure. Likewise, elements and/or components, if any, represented with dashed lines, indicate alternative examples of the present disclosure. One or more elements shown in solid and/or dashed lines may be omitted from a particular example without departing from the scope of the present disclosure. Environmental elements, if any, are represented with dotted lines. Virtual (imaginary) elements may also be shown for clarity. Those skilled in the art will appreciate that some of the features illustrated in the figures, may be combined in various ways without the need to include other features described in the figures, other drawing figures, and/or the accompanying disclosure, even though such combination or combinations are not explicitly illustrated herein. Similarly, additional features not limited to the examples presented, may be combined with some or all of the features shown and described herein.

In <FIG>, referred to above, the blocks may represent operations and/or portions thereof and lines connecting the various blocks do not imply any particular order or dependency of the operations or portions thereof. Blocks represented by dashed lines indicate alternative operations and/or portions thereof. Dashed lines, if any, connecting the various blocks represent alternative dependencies of the operations or portions thereof. It will be understood that not all dependencies among the various disclosed operations are necessarily represented. <FIG> and the accompanying disclosure describing the operations of the method(s) set forth herein should not be interpreted as necessarily determining a sequence in which the operations are to be performed. Rather, although one illustrative order is indicated, it is to be understood that the sequence of the operations may be modified when appropriate. Accordingly, certain operations may be performed in a different order or substantially simultaneously. Additionally, those skilled in the art will appreciate that not all operations described need be performed.

In the following description, numerous specific details are set forth to provide a thorough understanding of the disclosed concepts, which may be practiced without some or all of these particulars. In other instances, details of known devices and/or processes have been omitted to avoid unnecessarily obscuring the disclosure. While some concepts will be described in conjunction with specific examples, it will be understood that these examples are not intended to be limiting.

Unless otherwise indicated, the terms "first", "second", etc. are used herein merely as labels, and are not intended to impose ordinal, positional, or hierarchical requirements on the items to which these terms refer.

Reference herein to "one example" means that one or more feature, structure, or characteristic described in connection with the example is included in at least one implementation. The phrase "one example" in various places in the specification may or may not be referring to the same example.

Claim 1:
An additive manufacturing system (<NUM>) comprising:
a build plate (<NUM>) having a longitudinal axis (<NUM>) and a lateral axis (<NUM>);
a powder spreading unit (<NUM>) having a plurality of recoater blades (<NUM>) configured to spread powder (<NUM>, 298A, 298B) onto the build plate (<NUM>), at least one of the plurality of recoater blades (<NUM>) extending at least partially along the lateral axis (<NUM>) and being configured to move relative to the build plate (<NUM>) along the longitudinal axis (<NUM>); and
at least one vibration mechanism (<NUM>) coupled to one or more of the build plate (<NUM>) and the at least one of the plurality of recoater blades (<NUM>), the at least one vibration mechanism (<NUM>) being configured for vibratory compaction of the powder (<NUM>, 298A, 298B) spread on the build plate (<NUM>), and including an array of vibration mechanisms (<NUM>) coupled to the at least one of the plurality of recoater blades (<NUM>), extending at least in a direction of the lateral axis (<NUM>), or coupled to the build plate (<NUM>), extending along one or more of the longitudinal axis (<NUM>) and the lateral axis (<NUM>),
wherein the plurality of recoater blades (<NUM>) includes a first recoater blade (132A) and a second recoater blade (132B), the first recoater blade (132A) having a first serration pattern (300P) on an end nearest the powder (<NUM>, 298A, 298B) on the build plate (<NUM>), and the second recoater blade (132B) having a second serration pattern (301P) on an end nearest the powder (<NUM>, 298A, 298B) on the build plate (<NUM>), wherein the first serration pattern (300P) and the second serration pattern (301P) is different from one another,
wherein at least one serration of the first serration pattern is arranged at a first angle (<NUM>) relative to a reference plane (<NUM>) that extends normal from the build plate (<NUM>) and at least one serration of the second serration pattern is arranged at a second angle (<NUM>) relative to the reference plane (<NUM>), the first angle being different than the second angle, to move powder particles of the powder in a direction transverse to a travel direction of the powder spreading unit.