Systems and methods for additive manufacturing of objects

Abstract

To provide systems and methods for powder bed binder jetting additive manufacturing.SOLUTION: A method of additively manufacturing an object (130) includes successively forming multiple powder layers (114) by depositing powder (104) over a build platform (112) using a powder-deposition apparatus. The method also includes successively forming a binder shell (116) by bonding selected regions of each of the multiple powder layers (114) before forming each successive one of the multiple powder layers (114) using a binder-delivery apparatus. The binder shell (116) encloses a portion of the powder (104). The method further includes densifying the portion of the powder (104) surrounded by the binder shell (116) using a consolidation apparatus.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present disclosure relates generally to additive manufacturing, and more particularly to systems and methods for powder bed binder jet additive manufacturing for forming objects from powder materials. [Background technology]

[0002] Metal injection molding (MIM) is a metal processing method in which powdered metal is mixed with one or more binders to form a feedstock. The feedstock is then injected as a liquid into a mold via injection molding. The resulting "green part" is then cooled and removed from the mold. After molding, the green part undergoes conditioning operations (e.g., using solvents, thermal furnaces, catalytic processes, or a combination of these) to remove some of the binder, creating a "brown part." The brown part is then sintered to remove the remaining binder and densify the metal particles to create a "finished part." MIM has the advantage of being able to cost-effectively produce large quantities or complex parts. However, MIM requires expensive, permanent molds, which may make it less cost-effective for producing small quantities of parts.

[0003] Metal binder jetting can offer a cost-effective alternative to the MIM process for producing low-volume parts. In metal binder jetting, a liquid binder is selectively added to bond metal powder particles layer by layer to form a brown body. The brown body is then subjected to a sintering operation to remove the binder and densify the metal particles to create the finished part.

[0004] However, in both MIM and metal binder jetting, the metal particles can trap some of the binder before releasing all of it during densification in the sintering operation. This can result in binder inclusions in the finished part or a lower-than-desired density. This is particularly problematic when producing relatively thick parts. Therefore, those skilled in the art are continuing their research and development efforts to provide improved additive manufacturing techniques, such as powder bed binder jetting additive manufacturing. Summary of the Invention

[0005] The following is a non-exhaustive list of embodiments of the subject matter of the present disclosure, which may include both claimed and unclaimed embodiments.

[0006] In one embodiment, a disclosed additive manufacturing system includes a build platform. The additive manufacturing system also includes a powder deposition device configured to deposit powder onto the build platform to successively form multiple powder layers. The additive manufacturing system further includes a binder delivery device configured to supply binder to selected regions of each successive layer of the multiple powder layers to successively form binder shells. The additive manufacturing system further includes a compaction device configured to densify portions of the powder surrounded by the binder shells.

[0007] In one embodiment, the disclosed method for additively manufacturing an object includes (1) sequentially forming a plurality of powder layers by depositing powder, and (2) sequentially forming a binder shell by bonding selected regions in each of the plurality of powder layers prior to forming each subsequent layer of the plurality of powder layers, the binder shell enclosing a portion of the powder.

[0008] In one embodiment, the disclosed additively manufactured object is made by a process that includes: (1) sequentially forming a plurality of powder layers by depositing powder; and (2) forming a binder shell by bonding selected regions in each of the plurality of powder layers prior to forming each subsequent layer of the plurality of powder layers to form a plurality of shell layers of a binder shell, the binder shell surrounding a powder core.

[0009] Other embodiments of the disclosed additive manufacturing systems, methods, and additively manufactured objects will become apparent from the following detailed description, the accompanying drawings, and the appended claims. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram of an example additive manufacturing system. [Figure 2-5] FIG. 1 is a schematic diagram of an example of sequential formation of multiple powder layers and multiple shell layers. [Figure 6] FIG. 1 is a schematic diagram of an example of an additively manufactured object that includes a binder shell and a powder core surrounded by the binder shell. [Figure 7-8] FIG. 1 is a schematic diagram of an example process for densifying powder surrounded by a portion of a binder shell using a vibration mechanism. [Figure 9-10] FIG. 1 is a schematic diagram of an example process for densifying powder surrounded by a portion of a binder shell using a tamping head. [Figure 11-12] FIG. 1 is a schematic diagram of an example process for densifying powder surrounded by a portion of a binder shell using multiple tamping pins. [Figure 13] 1 is a flowchart of an example method for additively manufacturing an object. [Figure 14] 1 is a flowchart of an aircraft production and service method. [Figure 15] FIG. 1 is a schematic block diagram of an example aircraft. DETAILED DESCRIPTION OF THE INVENTION

[0011] In the following detailed description, reference will be made to the accompanying drawings, which illustrate specific embodiments of the subject matter disclosed herein. Other embodiments having different structures and processes do not depart from the scope of this disclosure. Also, like reference numerals may refer to the same features, elements, or components in different drawings. Throughout this disclosure, any one of multiple items may be generally referred to as that item, and multiple items may be collectively referred to as items.

[0012] Illustrative, non-exclusive examples of the subject matter disclosed herein, including as set forth in the claims, are provided below. As used herein, the term "an embodiment" means that one or more features, structures, elements, components, properties, and / or operational steps described in connection with that embodiment are included in at least one aspect, embodiment, and / or implementation of the subject matter disclosed herein. Thus, the phrases "one embodiment," "another embodiment," "one or more embodiments," and similar phrases used in various places throughout this disclosure do not necessarily refer to the same embodiment. Furthermore, elements characteristic of one embodiment may, but do not necessarily, include elements characteristic of other embodiments. Furthermore, elements characteristic of one embodiment may, but do not necessarily, be combined with elements characteristic of other embodiments.

[0013] In the following description, numerous specific details are presented to provide a thorough understanding of the disclosed concepts; however, the disclosure may be practiced without some or all of these details. In other instances, details of well-known devices and / or processes are omitted to avoid unduly obscuring the disclosure. Although some concepts are described in connection with specific examples, these examples are not intended to limit the disclosure.

[0014] The present disclosure recognizes that powder bed binder jet additive manufacturing (PBM) can enable cost-effective production of complex parts. The present disclosure also recognizes that relatively thick parts produced by PBM may contain inclusions in the form of unremoved binder and / or high porosity, which can lead to reduced mechanical properties of the part and limited design space for PBM. Therefore, current PBM processes may not be recommended for producing relatively thick parts, e.g., parts greater than 0.125 inches (3.175 mm). The present disclosure also recognizes that when a design requires a relatively thick portion of a part, a sintering operation must be performed at a relatively low temperature for a relatively long time, increasing the process cycle time and overall manufacturing costs. The present disclosure further recognizes that the sintering operation employed in PBM can result in non-uniform shrinkage of the Brownian body due to a lack of desired powder densification and uniformity.

[0015] Referring to Figures 1-13 by way of example, the present disclosure relates to an additive manufacturing system 100 (generally referred to herein as a system), a method 1000 for additively manufacturing an object 130, and an object 130 produced by the system 100 and / or method 1000.

[0016] In one or more embodiments, the system 100 and method 1000 are implementations of powder bed binder jetting used to create an object 130 from a powder 104. The present disclosure recognizes that manufacturing objects and other parts by powder bed binder jetting has advantages in terms of production and design flexibility. The present disclosure also recognizes potential problems, such as those discussed above, when manufacturing objects and other parts by powder bed binder jetting. Embodiments of the system 100 and method 1000 address these potential problems.

[0017] Embodiments of the system 100 and method 1000 facilitate the formation of an object 130 in a “brown” state. In the brown state, the object 130 includes an outer or external binder shell 116 ( FIGS. 1 and 6 ) formed of bound powder 104 and an inner or internal powder core 150 ( FIG. 6 ) formed of unbound (e.g., loose) powder 104 surrounded by the binder shell 116. Embodiments of the system 100 and method 1000 also provide an increased density for the powder core 150 of the (brown) object 130, which in turn increases the density of the (finished) object 130 after the sintering process. Embodiments of the system 100 and method 1000 further enable the (finished) object 130 to maintain its designed or intended mechanical properties after the sintering process by eliminating binder inclusion, reducing porosity, and achieving near-100% density. Thus, embodiments of the system 100 and method 1000 advantageously expand the design space of powder bed binder jet manufacturing and provide a rapid, low-cost method for producing objects 130 without expensive, long-term permanent molds.

[0018] Generally, the powder 104 includes any powder material suitable for layer-by-layer bonding to create the binder shell 116 and for solidification, such as by a sintering operation. Suitable examples of the powder 104 include metal powders and alloy powders. However, the powder 104 is not limited to metal / alloy powders, but may also include ceramic powders, polymer powders, and the like. In other examples, the powder 104 may also include a combination of different types of powder materials or constituent powders.

[0019] Generally, object 130 includes any additively manufactured object produced using system 100 and / or according to method 1000. For example, object 130 includes any article, part, component, or other three-dimensional object produced by a powder bed binder jet additive manufacturing process. As described in more detail herein, in one or more embodiments, object 130 may take the form of a "Brown body." Also, in one or more embodiments, object 130 may take the form of a "finished product."

[0020] 1 schematically illustrates an example system 100. In one or more embodiments, system 100 includes a build platform 112, a powder deposition device 102, a binder supply device 106, and a consolidation device 118. Generally, system 100 is configured to convert a three-dimensional (3D) model into two-dimensional (2D) layers. System 100 deposits and selectively bonds powder 104 according to a pre-programmed build shape and a pre-programmed tool path (e.g., G-code) for each 2D layer using a computer numerically controlled (CNC) additive process.

[0021] Referring to FIG. 1 , in one or more embodiments, the system 100 includes a build chamber 110. A build platform 112 is located within the build chamber 110. For purposes of illustration, the front wall (or front rail) of the build chamber 110 has been omitted from FIG. 1 . The build platform 112 is provided to support a powder bed 134 and an object 130 to be fabricated by a powder bed binder jet additive manufacturing process. A build chamber 220 forms a peripheral boundary with the build platform 112 and a peripheral boundary with the powder bed 134.

[0022] In one or more embodiments, seals (not shown) are provided in contact with the build platform 112 and the build chamber 110 to ensure that the powder 104 is contained within the build chamber 110 during the formation of the object 130.

[0023] In the illustrated embodiment, the build chamber 110 and build platform 112 are shown as having a square cross-section, but in other embodiments, the build chamber 110 and build platform 112 may be of any geometric shape having a closed cross-section, such as a circle, an oval, or a rectangle.

[0024] In one or more embodiments, the build platform 112 is movable relative to the powder deposition apparatus 102 and / or the binder supply apparatus 106. In one or more embodiments, the build platform 112 moves vertically (e.g., lowers) within the build chamber 110 relative to the powder deposition apparatus 102 and / or the binder supply apparatus 106 as successive layers of the plurality of powder layers 114 and the plurality of shell layers 132 are formed. In one or more embodiments, the build platform 112 moves horizontally relative to the powder deposition apparatus 102 as each successive layer of the plurality of powder layers 114 is formed and / or relative to the binder supply apparatus 106 as each successive layer of the plurality of shell layers 132 is formed. In one or more embodiments, the build platform 112 rotates about a vertical axis relative to the powder deposition apparatus 102 as each layer of the plurality of powder layers 114 is formed and / or relative to the binder supply apparatus 106 as each layer of the plurality of shell layers 132 is formed.

[0025] In one or more embodiments, system 100 includes a build platform actuator (not shown) coupled to build platform 112 and configured to drive movement of build platform 112. In one or more embodiments, build platform actuator includes or takes the form of a linear actuator. In one or more embodiments, build platform actuator includes a turntable coupled to build platform 112.

[0026] The powder deposition apparatus 102 is configured to deposit powder 104. In one or more embodiments, the powder deposition apparatus 102 is configured to selectively deposit powder 104 onto a powder bed 134 to sequentially form each of the multiple powder layers 114. For example, the powder deposition apparatus 102 is configured to deposit powder 104 to sequentially form the multiple powder layers 114 on the build platform 112.

[0027] In one or more embodiments, the powder deposition apparatus 102 is movable relative to the build platform 112. In one or more embodiments, the powder deposition apparatus 102 moves horizontally relative to the build platform 222 as each successive layer of the plurality of powder layers 114 is formed. In one or more embodiments, the powder deposition apparatus 202 moves vertically relative to the build platform 112 as each successive layer of the plurality of powder layers 114 is formed. In one or more embodiments, the powder deposition apparatus 102 has multiple degrees of freedom to accommodate multi-axis movement for depositing the powder 104 onto the powder bed 134.

[0028] In one or more embodiments, the system 100 includes a powder deposition actuator 138 coupled to the powder deposition device 102. The powder deposition actuator 138 is configured to drive the movement of the powder deposition device 102. In one or more embodiments, the build platform actuator 138 includes or takes the form of a linear actuator, a robotic actuator arm (e.g., a six-axis robotic actuator arm), or the like.

[0029] In one or more embodiments, the powder deposition apparatus 102 includes or takes the form of a recoater 136 that deposits the powder 104 across the powder bed 134. In one or more embodiments, the recoater 136 is configured to deposit or dispense the powder 104 onto the powder bed 134 to successively form each of the multiple powder layers 114. In other embodiments, the powder deposition apparatus 102 includes or takes the form of any one of a variety of other types of mechanisms, such as a powder sprayer, that can deposit or dispense the powder 104 onto the powder bed 134.

[0030] In one or more embodiments, the recoater 136 includes a discharge chamber (e.g., a powder feeder or powder hopper) configured to hold the powder 104. The discharge chamber includes a discharge opening for discharging the powder 104. Alternatively, in one or more embodiments, the system 100 includes a powder chamber (not shown) that holds the supply powder 104 and positions the powder 104 for deposition onto the powder bed 134. The recoater 136 is configured to move the powder 104 from the powder chamber to the build chamber 110 and deposit the powder 104 onto the powder bed 134.

[0031] In one or more embodiments, the recoater 136 includes a roller. In one or more embodiments, the roller is configured to collect and deposit the powder 104 on the build platform 112 or a previously formed layer of the plurality of powder layers 114. In one or more embodiments, the roller is configured to level the deposited powder 104 on the powder bed 134. In one or more embodiments, the recoater 136 additionally or alternatively includes another type of leveling device, such as a blade, configured to level the deposited powder 104 on the powder bed 134.

[0032] The binder supply device 106 is configured to apply the binder 108 to the powder 104. In one or more embodiments, the binder supply device 106 is configured to selectively bond (e.g., combine) some of the powder 104 in each of the plurality of powder layers 114 to successively form each of the plurality of shell layers 132. For example, the binder supply device 106 is configured to supply the binder 108 to selected areas of each of the plurality of successive powder layers 114 to successively form binder shells 116.

[0033] In one or more embodiments, the binder supply apparatus 106 is movable relative to the build platform 112. In one or more embodiments, the binder supply apparatus 106 moves horizontally relative to the build platform 112 as each successive layer of the plurality of shell layers 132 is formed. In one or more embodiments, the binder supply apparatus 106 moves horizontally relative to the build platform 112 as each successive layer of the plurality of shell layers 132 is formed. vertical In one or more embodiments, the binder supply device 106 has multiple degrees of freedom to accommodate multi-axis movement to bind the powder 104 in any position.

[0034] In one or more embodiments, system 100 includes a binder dispensing actuator 140 coupled to binder dispensing device 106. Binder dispensing actuator 140 is configured to drive movement of binder dispensing device 106. In one or more embodiments, binder dispensing actuator 140 includes or takes the form of a linear actuator, a robotic actuator arm (e.g., a six-axis robotic actuator arm), or the like.

[0035] The binder 108 includes any binding agent or material suitable for binding the powder 104 together to form a solid cross-sectional layer of the binder shell 116 (e.g., any one of the shell layers 132). In one or more embodiments, the binder supply device 106 includes or takes the form of a binder jet printhead 142 that places (e.g., deposits droplets of) the binder 108 onto the powder bed 134, binding the powder 104 together into a solid layer of material (e.g., shell layer 132).

[0036] In one or more embodiments, the system 200 includes a controller 144. The controller 144 communicates with the operating components of the system 100 via one or more communication lines, such as wired or wireless communication. In one or more embodiments, the controller 144 is configured to generate command signals to control the movement and operation of the powder deposition device 102 and the binder supply device 106. For example, the controller 144 selectively controls the movement of the powder deposition device 102 and the binder supply device 106 according to a predetermined plan (e.g., G-code) stored in the controller 144 to sequentially deposit and combine the powder 104.

[0037] In one or more embodiments, system 100 includes a power supply 146. Power supply 146 is configured to provide power to the components of system 100 as needed. In one or more embodiments, power supply 146 may be a single power supply or may include multiple power supplies that work in conjunction to provide the required power output. Alternatively, multiple power supplies may operate independently and individually power specific components of system 100. Power supply 146 may be either an AC power supply or a DC power supply, or a combination of AC and DC may be used.

[0038] 2-6 illustrate an example of a process that may be used to form object 130 using system 100 (FIG. 1). Throughout this disclosure, and particularly with respect to FIGS. 2-6, multiple powder layers 114 may be individually referred to as powder layer 114-1 through powder layer 114-N. Similarly, throughout this disclosure, and particularly with respect to FIGS. 2-6, multiple shell layers 132 may be individually referred to as shell layer 132-1 through shell layer 132-N.

[0039] As shown in Figure 2, in one or more embodiments, the powder deposition device 102, under direction from the controller 144, deposits powder 104 across the build platform 112 to form a first (e.g., initial) powder layer 114-1 (e.g., the first of the multiple powder layers 114). As shown in Figure 3, after the first powder layer 114-1 is formed, under direction from the controller 144, the binder supply device 106 is activated to move across the first powder layer 114-1 and strategically apply binder 108 to bind selected portions of the powder 104 in the first powder layer 114-1. By binding the selected portions of the powder 104 in the first powder layer 114-1, a first shell layer 132-1 (e.g., the first of the multiple shell layers 132) of the object 130 is formed on the build platform 112.

[0040] In one or more embodiments, the first shell layer 132-1 forms or comprises the bottom of the binder shell 116. In one or more embodiments, the first shell layer 132-1 has a thickness approximately equal to that of the first powder layer 114-1. In one or more embodiments, the thickness of the first shell layer 132-1 is approximately 0.0625 inches (1.587 millimeters). In one or more embodiments, the thickness of the first shell layer 132-1 is less than approximately 0.0625 inches (1.587 millimeters).

[0041] 3 , in one or more embodiments, the bottom of the binder shell 116 is formed entirely by one shell layer 132 (e.g., first shell layer 132-1). In other embodiments, the bottom of the binder shell 116 may be formed entirely by two or more shell layers 132 (e.g., a second shell layer formed on the first shell layer, a third shell layer formed on the second shell layer, etc.). The number of shell layers 132 used to form the bottom of the binder shell 116 depends on factors such as the desired thickness of the entire binder shell 116, the desired thickness of the bottom of the binder shell 116, the contour shape of the bottom of the binder shell 116, the overall dimensions of the object 130, the thickness of a given powder layer 114, and the volume and / or density of the powder 104 (e.g., powder core 150) to be surrounded by the binder shell 116.

[0042] In one or more embodiments, the build platform 112 is selectively lowered by a single layer thickness under direction from the controller 144. As shown in FIG. 4 , the powder deposition device 102 deposits powder 104 across the first powder layer 114-1 under direction from the controller 144 to form a second powder layer 114-2 (e.g., the second and subsequent layer of the plurality of powder layers 114). After the second powder layer 114-2 is formed, the binder supply device 106 is activated under direction from the controller 144 to move across the second powder layer 114-2 and strategically apply binder 108 to bond selected portions of the powder 104 of the second powder layer 114-2. The bonding of selected portions of the powder of the second powder layer 114-2 forms a second shell layer 132-2 (e.g., the second and subsequent layer of the plurality of shell layers 132) on the first shell layer 132-1. After the second shell layer 132-1 is formed, the unbound portions of the powder 104 (e.g., the first powder core layer 152-1) are surrounded by the first shell layer 132-1 and the second shell layer 132-2, while the other unbound portions of the powder 104 remain packed around the first shell layer 132-1 and the second shell layer 132-2.

[0043] In one or more embodiments, the second shell layer 132-2 forms part of a continuous side (having a closed cross section) of the binder shell 116. In one or more embodiments, the thickness of the second shell layer 132-2 is approximately 0.0625 inches (1.587 mm). In one or more embodiments, the thickness of the second shell layer 132-1 is less than approximately 0.0625 inches (1.587 mm).

[0044] In one or more embodiments, as shown in FIGS. 5 and 6, this forming and bonding process is repeated multiple times to form multiple intermediate powder layers 114 and multiple intermediate shell layers 132, ultimately forming an object 130 (FIG. 6) including a binder shell 116 and a powder core 150 surrounded by the binder shell 116.

[0045] Generally, each successive layer of the plurality of powder layers 114 is formed on top of the previously formed layer below in the plurality of powder layers 114 and the previously formed layer below in the plurality of shell layers 132. Each successive layer of the plurality of shell layers 132 is formed on top of and bonded to the previously formed layer below in the plurality of shell layers 132 to form a new shell layer 132 and a new powder core layer 152. After forming each successive layer of shell layers 132, additional unbonded portions of the powder 104 (e.g., each successive layer of the plurality of powder core layers 152) are surrounded by the first shell layer 132-1 and the plurality of intermediate shell layers 132 (e.g., shell layers 132-2 through 132-8). Other additional unbonded portions of the powder 104 remain packed around the first shell layer 132-1 and the plurality of intermediate shell layers 132.

[0046] In one or more embodiments, each of the plurality of intermediate shell layers 132 (e.g., shell layers 132-2 to 132-8) forms a continuous portion of a continuous side portion (e.g., having a closed cross-section) of the binder shell 116. In one or more embodiments, each of the plurality of intermediate shell layers 132 (e.g., shell layers 132-2 to 132-8) has a thickness of approximately 0.0625 inches (1.587 mm). In one or more embodiments, each of the plurality of intermediate shell layers 132 (e.g., shell layers 132-2 to 132-8) has a thickness of less than approximately 0.0625 inches (1.587 mm). In one or more embodiments, each of the plurality of intermediate shell layers 132 (e.g., shell layers 132-2 to 132-8) has a uniform thickness. In one or more embodiments, the thickness of at least one of the plurality of intermediate shell layers 132 (e.g., shell layers 132-2 to 132-8) is different from the thickness of at least another of the plurality of intermediate shell layers 132 (e.g., shell layers 132-2 to 132-8).

[0047] As shown in FIG. 6 , in one or more embodiments, the powder deposition device 102, under direction from the controller 144, deposits powder 104 across a previously formed powder layer 114 (e.g., powder layer 114-8) to form a final powder layer 114-N (e.g., the last of the multiple powder layers 114). After the final powder layer 114-N is formed, under direction from the controller 144, the binder supply device 106 is activated to cross the final powder layer 114-N and strategically apply binder 108 to bond selected portions of the powder 104 in the final powder layer 114-N. Bonding the selected portions of the powder 104 in the final powder layer 114-N forms a final shell layer 132-N (e.g., the last of the multiple shell layers 132) of the object 130. After the final shell layer 132-N is formed, the unbonded portions of the powder 104 (e.g., powder core layer 150) are surrounded by the binder shell 116. The remaining unbound portion of the powder 104 remains packed around the binder shell 116 .

[0048] In one or more embodiments, the final shell layer 132-N forms or comprises the top portion of the binder shell 116. In one or more embodiments, the final shell layer 132-N has a thickness approximately equal to the thickness of the final powder layer 114-N. In one or more embodiments, the thickness of the final shell layer 132-N is approximately 0.0625 inches (1.587 millimeters). In one or more embodiments, the thickness of the final shell layer 132-N is less than approximately 0.0625 inches (1.587 millimeters).

[0049] 6, in one or more embodiments, the top of the binder shell 116 is formed entirely by one shell layer 132 (e.g., final shell layer 132-N). In other embodiments, the top of the binder shell 116 may be formed by two or more shell layers 132. The number of shell layers 132 used to form the top of the binder shell 116 depends on factors such as the desired thickness of the entire binder shell 116, the desired thickness of the top of the binder shell 116, the contour shape of the top of the binder shell 116, the overall dimensions of the object 130, the thickness of a given powder layer 114, and the volume and / or density of the powder 104 (e.g., powder core 150) surrounded by the binder shell 116.

[0050] 6, in one or more embodiments, the binder shell 116 has a contour that generally matches the final shape of the object 130. Accordingly, the bottom, sides, and / or top of the binder shell 116 may have one or more straight sections and / or one or more curved sections. Similarly, the bottom, sides, and / or top of the binder shell 116 may include one or more horizontally oriented sections, one or more vertically oriented sections, and / or one or more angled sections.

[0051] Generally, the binder shell 116 has a closed cross-sectional shape suitable for surrounding and containing the powder core 150. In one or more embodiments, the binder shell 116 has a thickness of about 0.0625 inches (1.587 mm). In one or more embodiments, the binder shell 116 has a thickness of less than about 0.0625 inches (1.587 mm). In one or more embodiments, the binder shell 116 has a constant thickness. In one or more embodiments, the binder shell 116 has a varying thickness.

[0052] 1 , in one or more embodiments, the system 100 includes a consolidation device 118 configured to compact, densify, settle, pack, or otherwise densify at least a portion of the powder 104 surrounded by the binder shell 116 (e.g., a portion of the powder 104 inside and surrounded by the shell layers 132) that forms the powder core 150 ( FIG. 6 ) of the object 130. Consolidating the powder core 150 of the object 130 in its brown state can result in an object 130 that is denser in its finished state (e.g., after a sintering operation) than those produced by current binder jetting methods.

[0053] In one or more embodiments, the controller 144 is configured to generate command signals to control the movement and / or operation of the compaction device 118. For example, the controller 144 selectively controls the movement and / or activation of the compaction device 118 according to a predetermined plan stored in the controller 144.

[0054] 1 , 8 , and 9 , in one or more embodiments, the compaction apparatus 118 includes a vibration mechanism 120. The vibration mechanism 120 is coupled to the build platform 112. The vibration mechanism 120 is configured to compact (e.g., settle) the portion of the powder 104 that is surrounded by (e.g., within) the binder shell 116. The vibration mechanism 120 may include any of a variety of vibration mechanisms suitable for generating and transmitting vibrational energy to the powder bed 134.

[0055] In one or more embodiments, the vibration mechanism 120 includes an ultrasonic vibration element 122 configured to generate ultrasonic vibrations that mechanically impact the interior of the build platform 112 and powder bed 134, agitating the powder 104 within the build chamber 110 to achieve denser and / or more uniform powder packing.

[0056] In one or more embodiments, the vibration mechanism 120 can be used to achieve a desired density of the powder 104 (e.g., powder core 150). Generally, the vibration energy (e.g., ultrasonic vibrations) generated and transmitted to the powder 104 by the vibration mechanism 120 is sufficient to pack the powder 104. Ideally, the vibration energy is sufficient to prevent post-formation settling of the powder 104 after application of the binder 108 and formation of the multiple shell layers 132, and to prevent post-formation settling of the powder 104 forming the powder core 150 within the binder shell 116 before or during a consolidation (e.g., sintering) operation. The vibration energy is also configured to prevent rising of the powder 104 in response to the vibration energy.

[0057] 7, in one or more embodiments, under direction from a controller 144, the vibration mechanism 120 is activated to transfer vibration energy to the powder bed 134 to compact the powder 104 in the powder bed 134. In one or more embodiments, the vibration mechanism 120 is activated after each of the plurality of powder layers 114 is formed. In one or more embodiments, the vibration mechanism 120 is activated after each of the plurality of shell layers 132 is formed.

[0058] As shown in FIG. 7 , after compaction of the powder 104, the powder 104 in the powder bed 134 may settle and become more densely packed. Therefore, gaps may form between the top surface of the most recently formed shell layer 132 and the top surface of the powder bed 134 (e.g., the top surfaces of the most recently formed powder layer 114 and / or the most recently formed powder core layer 152). As shown in FIG. 8 , in one or more embodiments, the powder deposition device 102, under direction from the controller 144, recoats the powder bed 134 by depositing powder 104 across the most recently formed powder layer 114 to form a fill layer 154. The fill layer 154 fills in any gaps created during the vibration compaction operation and forms a smooth layer of powder 104 before the formation of the next powder layer 114.

[0059] 1 and 9-12, in one or more embodiments, the compaction device 118 includes a tamping mechanism 124. The tamping mechanism 124 is configured to compact (e.g., compress) the portion of the powder 104 that is surrounded by (e.g., within) the binder shell 116. The tamping mechanism 124 may include any of a variety of tamping mechanisms suitable for applying a compressive force to the powder bed 134.

[0060] In one or more embodiments, the tamping mechanism 124 is movable relative to the build platform 112. In one or more embodiments, the tamping mechanism 124 moves horizontally relative to the build platform 112 after each successive one of the plurality of powder layers 114 and / or shell layers 132 is formed. In one or more embodiments, the tamping mechanism 124 moves horizontally relative to the build platform 112 after each successive one of the plurality of powder layers 114 and / or shell layers 132 is formed. vertical In one or more embodiments, the tamping mechanism 124 has multiple degrees of freedom to accommodate multi-axial movement of the tamping mechanism 124 at any position.

[0061] In one or more embodiments, system 100 includes a tamping mechanism actuator 148 coupled to tamping mechanism 124. Tamping mechanism actuator 148 is configured to drive the movement of tamping mechanism 124. In one or more embodiments, tamping mechanism actuator 148 includes or takes the form of a linear actuator, a robotic actuator arm (e.g., a six-axis robotic actuator arm), or the like.

[0062] In one or more embodiments, the tamping mechanism 124 may be used in addition to the vibration mechanism 120 when the vibration energy is insufficient to achieve a desired density of the powder 104 (e.g., the powder core 150). In one or more embodiments, the tamping mechanism 124 may be used instead of the vibration mechanism 120 to achieve a desired density of the powder 104 (e.g., the powder core 150). For example, the compaction device 118 may include both the vibration mechanism 120 coupled to the build platform 112 and configured to compact the portion of the powder 104 surrounded by the binder shell 116, and the tamping mechanism 124 configured to compress the portion of the powder 104 surrounded by the binder shell 116.

[0063] 9 , in one or more embodiments, the tamping mechanism 124 includes a tamping head 126. The tamping head 126 is configured to compress the portions of the powder 104 surrounded by the binder shells 116 region by region (e.g., regions in each of the plurality of powder core layers 152) in sequence.

[0064] In one or more embodiments, the tamping head 126 moves along the formed powder core layer 152 under direction from the controller 144 according to a predetermined plan stored in the controller 144. As the tamping head 126 moves along the powder core layer 152 under direction from the controller 144, the tamping head 126 is selectively activated to apply a compressive force to selected locations on the powder core layer 152, consolidating the powder 104 surrounded by the multiple shell layers 132. In one or more embodiments, the positioning of the tamping head 126 is controlled using CNC commands so that the compressive force is applied only to the locations on the powder core layer 152 surrounded by the corresponding shell layers 132, thereby preventing damage to the shell layers 132. In one or more embodiments, the tamping head 126 is positioned and activated after each of the multiple powder layers 114 is formed. In one or more embodiments, the tamping head 126 is positioned and activated after each of the multiple shell layers 132 is formed.

[0065] As shown in FIG. 9 , after compaction of the powder 104, the powder 104 forming the multiple powder core layers 152 may settle and become more densely packed. Thus, gaps may form between the top surface of the most recently formed shell layer 132 and the top surface of the powder core 150 (e.g., the top surface of the most recently formed powder core layer 152). As shown in FIG. 10 , in one or more embodiments, the powder deposition device 102, under direction from the controller 144, deposits powder 104 across the most recently formed powder layer 114 to recoat the powder bed 134 and form a fill layer 154 on top of the powder core 150. The fill layer 154 fills in any gaps created during the compaction operation and forms a smooth layer of powder 104 before the formation of the next powder layer 114.

[0066] 11 and 12 , in one or more embodiments, the tamping mechanism 124 includes multiple tamping pins 128. The multiple tamping pins 128 are configured to simultaneously compress the entire portion of the powder surrounded by the binder shell 116 (e.g., the entire portion of each of the multiple powder core layers 152).

[0067] In one or more embodiments, the plurality of tamping pins 128 are positioned above the powder bed 134 under direction from the controller 144. Under direction from the controller 144, selected ones of the plurality of tamping pins 128 are selectively activated according to a predetermined plan stored in the controller 144 to apply a compressive force to multiple locations on the powder core layer 152 and consolidate the powder 104 surrounded by the multiple shell layers 132. In one or more embodiments, the selective activation of only selected ones of the plurality of tamping pins 128 is controlled using CNC commands so that the compressive force is applied only to the locations of the powder core layer 152 surrounded by the corresponding shell layer 132, thereby preventing damage to the shell layer 132. In one or more embodiments, the plurality of tamping pins 128 are positioned and selectively activated after each of the plurality of powder layers 114 is formed. In one or more embodiments, the plurality of tamping pins 128 are positioned and selectively activated after each of the plurality of shell layers 132 is formed.

[0068] As shown in FIG. 11 , after compaction of the powder 104, the powder 104 forming the multiple powder core layers 152 may settle and become more densely packed. Thus, gaps may form between the top surface of the most recently formed shell layer 132 and the top surface of the powder core 150 (e.g., the top surface of the most recently formed powder core layer 152). As shown in FIG. 12 , in one or more embodiments, the powder deposition device 102, under direction from the controller 144, deposits powder 104 across the most recently formed powder layer 114 to recoat the powder bed 134 and form a fill layer 154 on top of the powder core 150. The fill layer 154 fills in any gaps created during the compaction operation and forms a smooth layer of powder 104 before the formation of the next powder layer 114.

[0069] 13 illustrates an example method 1000 for forming object 130. According to one or more embodiments, method 1000 uses system 100 (FIG. 1) to fabricate object 130. In turn, method 1000 includes multiple operational steps for implementing the forming, bonding, and consolidation methods described above with respect to FIGS.

[0070] In one or more embodiments, the method 1000 includes a step of sequentially forming (block 1002) multiple powder layers 114. In one or more embodiments, the method 1000 includes a step of depositing (block 1004) powder 104 to sequentially form multiple powder layers 114. In one or more embodiments, according to the method 1000, the steps of depositing powder 104 (block 1004) and sequentially forming multiple powder layers 114 (block 1002) are performed using a powder deposition apparatus 102.

[0071] In one or more embodiments, the method 1000 includes successively forming the binder shells 116 (block 1006). In one or more embodiments, the method 1000 includes bonding selected areas of each of the plurality of powder layers 114 before forming each subsequent layer of the plurality of powder layers 114 (block 1008) to successively form the binder shells 116. In one or more embodiments, according to the method 1000, successively forming the binder shells 116 (block 1006) includes supplying binder 108 to selected areas of each of the plurality of powder layers 114 and successively forming multiple shell layers 132 of the binder shells 116 that enclose the portions of the powder 104 that are surrounded by the binder shells 116. In one or more embodiments, according to the method 1000, the steps of bonding selected areas in each of the plurality of powder layers 114 (block 1008) and sequentially forming the binder shells 116 (block 1006) are performed using a binder supply device 106.

[0072] In one or more embodiments, the method 1000 includes densifying (block 1010) a portion of the powder 104 surrounded by the binder shell 116 (e.g., the powder core 150). In one or more embodiments, the method 1000 densifies (block 1010) a portion of the powder 104 surrounded by the binder shell 116 after forming (block 1002) each of the plurality of powder layers 114. In one or more embodiments, the method 1000 densifies (block 1010) a portion of the powder 104 surrounded by the binder shell 116 after forming (block 1002) each of the plurality of shell layers 132. In one or more embodiments, the method 1000 densifies (block 1010) a portion of the powder 104 surrounded by the binder shell 116 using a compaction device 118.

[0073] In one or more embodiments, according to the method 1000, densifying the portion of the powder 104 surrounded by the binder shell 116 (block 1010) includes applying vibrational energy to the portion of the powder 104 surrounded by the binder shell 116 (block 1012). In one or more embodiments, applying vibrational energy to the portion of the powder 104 surrounded by the binder shell 116 (block 1012) is performed using a vibration mechanism 120.

[0074] In one or more embodiments, according to the method 1000, densifying the portion of the powder 104 surrounded by the binder shell 116 (block 1010) includes applying a compressive force to the portion of the powder 104 surrounded by the binder shell 116 (block 1014). In one or more embodiments, applying a compressive force to the portion of the powder 104 surrounded by the binder shell 116 (block 1014) is performed using a tamping mechanism 124.

[0075] In one or more embodiments, according to the method 1000, densifying the portion of the powder 104 surrounded by the binder shell 116 (block 1010) includes applying vibrational energy to the portion of the powder 104 surrounded by the binder shell 116 (block 1012) and applying a compressive force to the portion of the powder 104 surrounded by the binder shell 116 (block 1014).

[0076] In one or more embodiments, according to the method 1000, the step of applying vibrational energy to the portion of the powder 104 surrounded by the binder shell 116 (block 1012) occurs before the step of forming each successive layer of the plurality of shell layers 132 of the binder shell 116. In one or more embodiments, according to the method 1000, the step of applying a compressive force to the portion of the powder 104 surrounded by the binder shell 116 (block 1014) occurs after the step of forming each successive layer of the plurality of shell layers 132 of the binder shell 116.

[0077] In one or more embodiments, the method 1000 includes forming the fill layer 154 after densifying the portion of the powder 104 surrounded by the binder shell 116 (block 1010).

[0078] According to method 1000, the steps of depositing powder 104 (block 1004), forming powder layer 114 (block 1002), bonding powder 104 (block 1008), forming binder shell 116 (block 1004), and densifying powder 104 (block 1010) are repeated, for example, multiple times to successively form multiple powder layers 114, successively form multiple shell layers 132, and successively densify portions of powder 104 surrounded by binder shell 116, ultimately forming brown-state object 130 (block 1016).

[0079] In one or more embodiments, after object 130 is fully formed, it is in a green state (e.g., a "green body"), encapsulated in unbonded portions of powder 104 (e.g., as shown in FIGS. 1 and 6), and allowed to harden and gain strength. Once hardened, object 130 assumes a brown state.

[0080] In one or more embodiments, the method 1000 includes sintering the object 130 (block 1018). Sintering the object 130 removes the binder 108 from the binder shell 116 and solidifies (e.g., bonds) the powder of the powder core 150 and the powder of the binder shell 116. Typically, the sintering process occurs in a controlled atmosphere furnace where the part is heat treated to burn off the binder 108. The sintering process fuses the particles together, resulting in a strong part with low porosity. After sintering, the finished object 130 is formed (block 1020).

[0081] Throughout this disclosure, example operational steps of method 1000 and / or components of system 100 described with respect to depositing powder 104 to form one of the plurality of powder layers 114 and combining powder 104 to form one of the plurality of shell layers 132 are equally applicable to operational steps and components for depositing powder 104 to form any other of the plurality of powder layers 114 and combining powder 104 to form any other of the plurality of shell layers 132. Additionally, additional components, such as additional powder deposition devices, additional binder feeders, additional compaction devices, powder hoppers, regulators, valves, sensors, etc., may be included in system 100 without departing from the scope of this disclosure.

[0082] As described, the controller 144 communicates with and controls the various components of the system 100. In one or more embodiments, the controller 144 is a computing device including a processor and memory. The memory, for example, is a computer-readable storage medium configured to store data necessary for the operation of the system 100 and / or the execution of the method 1000. The computer-readable storage medium is any medium that can be used to store information that can be subsequently accessed by a processor. Computer-readable storage media include, for example, computer memory and data storage devices. Computer memory may be fast-access memory and can be used, for example, to execute program instructions executable by the processor. Computer memory includes, for example, random access memory (RAM), flash memory, and read-only memory (ROM). Data storage devices are, for example, physical devices used to store any information or computer programs that can be accessed by a processor, such as an operating system, computer programs, program modules, and program data. Data storage devices and associated computer-readable storage media provide storage of computer-readable instructions, data structures, program modules, and other data for the system. Data storage devices include magnetic media such as floppy disks, hard disk drives, and magnetic tape; optical media such as compact discs (CDs), digital video discs (DVDs), and Blu-ray discs; and solid-state memory such as random access memory (RAM), flash memory, and read-only memory (ROM).

[0083] In one or more embodiments, the memory contains data packets comprising data necessary for controlled operation of the system 100. For example, one data packet may contain data necessary for controlling the powder deposition device 102, another data packet may contain data necessary for controlling the binder supply device 106, and yet another data packet may contain data necessary for controlling the compaction device 118. The processor communicates with the memory to obtain the data necessary for controlling the operation of the system 100.

[0084] In one or more embodiments, the subject matter of this disclosure is described with reference to symbolic representations of operations and processes that are performed by one or more computers or computer systems, unless otherwise specified. Accordingly, such operations and processes, sometimes referred to as being computer-executed, include manipulation by one or more processors of system 100, such as controller 144, of electrical signals representing data in a structured format. Such manipulation transforms data or maintains data in specific locations within system 100's memory, thereby reconfiguring or altering the operation of system 200 in ways well understood by those skilled in the art. The data structures in which data are maintained are physical locations in memory that have particular characteristics defined by the format of the data. While one or more examples have been described in the foregoing context, those skilled in the art will understand that, without limitation, some of the operations and processes described herein may also be implemented in hardware, software, and / or firmware, and / or some combination thereof.

[0085] 14 and 15, embodiments of the additive manufacturing system 100, method 1000, and additively manufactured object 130 may be used in connection with an aircraft manufacturing and service method 1100 shown in the flowchart of FIG. 14 and an aircraft 1200 shown generally in FIG. 15.

[0086] 15 , in one or more embodiments, aircraft 1200 includes an airframe 1202, an interior 1206, and a number of high-level systems 1204. Examples of high-level systems 1204 include one or more of a propulsion system 1208, an electrical system 1210, a hydraulic system 1212, and an environmental system 1214. In other examples, aircraft 1200 may include any number of other systems, such as a communication system, a guidance system, a weapons system, etc. Object 130 fabricated using additive manufacturing system 100 according to method 1000 may be a structure, assembly, subassembly, component, part, or any other portion of aircraft 1200, such as a portion of airframe 1202 or interior 1206.

[0087] 14 , before production begins, method 1100 includes specification and design (block 1102) and material procurement (block 1104) of aircraft 1200. During production of aircraft 1200, component and subassembly manufacturing (block 1106) and system integration (block 1108) of aircraft 1200 occur. Aircraft 1200 then undergoes certification and delivery (block 1110) and enters service (block 1112). Routine maintenance and service (block 1114) may include upgrading, reconfiguring, modifying, etc., one or more systems of aircraft 1200.

[0088] 14 may be performed or implemented by a system integrator, a third party, and / or an operator (e.g., a customer). System integrators include, but are not limited to, any number of spacecraft manufacturers and major system subcontractors. Third parties include, but are not limited to, any number of vendors, subcontractors, and suppliers. Operators include, but are not limited to, airlines, leasing companies, military organizations, service organizations, and the like.

[0089] Embodiments of the system 100, method 1000, and object 130 shown and described herein can be employed during any one or more steps of the manufacturing and service method 1100 illustrated in the flowchart of FIG. 14. In one example, implementing the disclosed system 100 and method 1000 can form part of part and subassembly manufacturing (block 1106) and / or system integration (block 1108). For example, implementing the disclosed system 100 and method 1000 to assemble the aircraft 1200 and / or its parts (e.g., the object 130) can correspond to part and subassembly manufacturing (block 1106) and can produce parts or subassemblies similar to those produced during the in-service life of the aircraft 1200 (block 1112). Embodiments of the disclosed system 100 and method 1000 can also be employed during system integration (block 1108) and certification and delivery (block 1110). Similarly, embodiments of the disclosed system 100 and method 1000 may be employed, for example, but not limited to, during the in-service life of the aircraft 1200 (block 1112) and during maintenance and service (block 1114).

[0090] Also, while an aerospace (e.g., aircraft or spacecraft) example is provided, the embodiments and principles disclosed herein may be applied to other industries, such as the automotive industry, construction industry, wind turbine industry, electronics industry, and other design and manufacturing industries. Thus, the embodiments and principles disclosed herein may also be applied to powder bed binder jet additive manufacturing processes for forming objects for use in other vehicles (e.g., land vehicles, watercraft, construction vehicles, etc.), machinery, and stand-alone structures in addition to aircraft and spacecraft.

[0091] As used herein, a system, apparatus, device, structure, article, element, component, or hardware that is "configured to" perform a particular function refers to one that can perform that particular function without any modification, and not one that requires any modification to perform that particular function. In other words, a system, apparatus, device, structure, article, element, component, or hardware that is "configured" to perform a particular function refers to one that is specifically selected, made, implemented, utilized, programmed, and / or designed to perform that particular function. As used herein, "configured" refers to a characteristic that a system, apparatus, structure, article, element, component, or hardware already possesses that enables the system, apparatus, structure, article, element, component, or hardware to perform that particular function without any modification. In this disclosure, a system, apparatus, device, structure, article, element, component, or hardware that is "configured" to perform a particular function may also or instead be described as being "adapted to" and / or "operative to" perform that function.

[0092] Unless otherwise specified, the terms "first," "second," "third," etc. are used herein merely as labels and do not impose any ordering, positional, or hierarchical requirements on the items referred to by these terms. Furthermore, a reference to, for example, a "second" item does not require or exclude the presence of, for example, a "first" item or lower ordinal item and / or a "third" or higher ordinal item.

[0093] As used herein, when "at least one of" is used in reference to a list of items, it means that one or more of the listed items may be used in various combinations, and that only one of each item in the list may be required. For example, "at least one of item A, item B, and item C" includes item A, item A and item B. This example further includes item A, item B, and item C, and item B and item C. As another example, "at least one of" includes, for example, two item A, one item B, and ten item C, four item B, and seven item C, or any other suitable combination.

[0094] In this disclosure, terms such as "coupled," "coupled," and the like mean that two or more elements are coupled, connected, fixed, attached, connected, in communication with, or otherwise associated (e.g., mechanically, electrically, fluidly, optically, electromagnetically) with one another. In various examples, these elements may be directly or indirectly associated. As an example, element A may be directly associated with element B. As another example, element A may be indirectly associated with element B, e.g., through another element C. It should be noted that not all associations between the various elements of the disclosure are necessarily shown. Thus, other connections may exist than those shown in the figures.

[0095] As used herein, the term "about" refers to a condition that is close to, but not exactly the same as, the described condition and performs a desired function or achieves a desired result. By way of example, the term "about" refers to a condition that is within a given acceptable tolerance or precision. For example, the term "about" refers to a condition that is within 10% of the described condition. However, the term "about" does not exclude a condition that is exactly the same as the described condition.

[0096] As will be appreciated by those skilled in the art, some of the above-described elements, features, and / or components shown in FIGS. 1-12 and 15 may be combined in various ways without including other features described in FIGS. 1-12 and 15, other figures, and / or the accompanying disclosure, without such combinations necessarily being expressly indicated in this disclosure. Similarly, additional features not limited to the examples shown may be combined with some or all of the features shown and described herein. Unless otherwise specified, the schematic illustrations of the above-described examples shown in FIGS. 1-12 and 15 are not intended to imply architectural limitations on the illustrated embodiment. Rather, they illustrate one exemplary structure, which should be understood as being subject to appropriate modification. Accordingly, modifications, additions, and / or omissions may be made to the illustrated structure. Furthermore, as will be appreciated by those skilled in the art, not all elements shown and described in FIGS. 1-12 and 15 need be included in every embodiment, and not all elements described herein necessarily appear in every illustrated embodiment.

[0097] In the above-described Figures 13 and 14, blocks may represent operations, steps, and / or portions thereof, and lines connecting various blocks do not imply a particular order or dependency relationship between these steps or portions thereof. It should be noted that not all dependencies between the various steps disclosed are necessarily shown. The above-described Figures 13 and 14 and the accompanying disclosure describing steps of the method described herein do not necessarily dictate the order in which these steps are performed. Rather, one exemplary order is shown, but it should be understood that the order of these steps can be changed as appropriate. Accordingly, modifications, additions, and / or omissions can be made to the illustrated steps, and some steps can be performed in a different order or simultaneously. Additionally, as will be appreciated by those skilled in the art, not all steps necessarily need to be performed.

[0098] Furthermore, references throughout this specification to features, advantages, or other similar language used herein do not imply that all of the features and advantages that may be realized in the embodiments disclosed herein are or should be included in any one embodiment. Rather, references to features and advantages mean that the particular feature, advantage, or characteristic described in connection with one embodiment is included in at least one embodiment. Thus, references to features, advantages, and similar language used throughout this disclosure may, but do not necessarily, refer to the same embodiment.

[0099] Furthermore, the present disclosure includes embodiments according to the following notes:

[0100] Appendix 1. A modeling platform (112) and a powder deposition device (102) configured to deposit powder (104) onto the build platform (112) to successively form multiple powder layers (114); a binder delivery device (106) configured to deliver binder (108) to selected areas of each successive one of the plurality of powder layers (114) so ​​as to successively form binder shells (116); a compaction device configured to densify a portion of the powder surrounded by the binder shell.

[0101] Appendix 2. The additive manufacturing system (100) of Appendix 1, wherein the compaction device (116) includes a vibration mechanism (120) coupled to the build platform (112) and configured to compact the portion of the powder (104) surrounded by the binder shell (116).

[0102] Appendix 3. The additive manufacturing system (100) of Appendix 2, wherein the vibration mechanism (120) includes an ultrasonic vibration element (122) configured to generate ultrasonic vibrations.

[0103] Appendix 4. The additive manufacturing system (100) of Appendix 1, wherein the compaction device (116) includes a tamping mechanism (124) configured to compress the portion of the powder (104) surrounded by the binder shell (116).

[0104] Appendix 5. The additive manufacturing system (100) of Appendix 4, wherein the tamping mechanism (124) includes a tamping head (126) configured to compress the portion of the powder (104) surrounded by the binder shell (116) region by region in a sequential manner.

[0105] Appendix 6. The additive manufacturing system (100) of Appendix 4, wherein the tamping mechanism (124) includes a plurality of tamping pins (128) configured to simultaneously compress the entire portion of the powder (104) surrounded by the binder shell (116).

[0106] Appendix 7. The compaction device (116) a vibration mechanism (120) coupled to the build platform (112) and configured to compact the portion of the powder (104) surrounded by the binder shell (116); and a tamping mechanism configured to compress the portion of the powder surrounded by the binder shell.

[0107] Appendix 8. A method (1000) for additively manufacturing an object (130), comprising: depositing powder (104) to successively form a plurality of powder layers (114); and successively forming a binder shell (116) by bonding selected areas of each of the plurality of powder layers (114) before forming each subsequent layer of the plurality of powder layers (114); The binder shell (116) surrounds a portion of the powder (104), according to the method (1000).

[0108] Clause 9. The method (1000) of clause 8, further comprising densifying the portion of the powder (104) surrounded by the binder shell (116).

[0109] Clause 10. The method (1000) of clause 9, wherein densifying the portion of the powder (104) surrounded by the binder shell (116) comprises applying vibrational energy to the portion of the powder (104) surrounded by the binder shell (116).

[0110] Clause 11. The method (1000) of clause 9, wherein densifying the portion of the powder (104) surrounded by the binder shell (116) comprises applying a compressive force to the portion of the powder (104) surrounded by the binder shell (116).

[0111] Appendix 12. The step of successively forming the plurality of powder layers (114) is performed using a powder deposition device (102); The continuous formation of the binder shells (116) is performed using a binder supply device (106); 10. The method (1000) of claim 9, wherein densifying the portion of the powder (104) surrounded by the binder shell (116) is performed using a compaction device (118).

[0112] Appendix 13. The method (1000) of Appendix 8, wherein continuously forming the binder shell (116) includes supplying a binder (108) to selected regions in each of the plurality of powder layers (114) to continuously form a plurality of shell layers (132) of the binder shell (116) surrounding the portion of the powder (104) surrounded by the binder shell (116).

[0113] Appendix 14. Applying vibrational energy to the portion of the powder (104) surrounded by the binder shell (116); 14. The method (1000) of claim 13, further comprising: applying a compressive force to the portion of the powder (104) surrounded by the binder shell (116).

[0114] Clause 15. The application of vibrational energy to the portion of the powder (104) surrounded by the binder shell (116) occurs before forming each successive layer of the plurality of shell layers (132) of the binder shell (116); 15. The method (1000) of claim 14, wherein applying a compressive force to the portion of the powder (104) surrounded by the binder shell (116) occurs after forming each successive layer of the plurality of shell layers (132) of the binder shell (116).

[0115] Appendix 16. The binder shell (116) a contour shape that corresponds to the final shape of the object (130); 9. The method (1000) of claim 8, wherein the thickness is less than 0.0625 inches.

[0116] Appendix 17. The method (1000) of Appendix 8, further comprising sintering the body (130) to remove the binder (108) from the binder shell (116) and solidify the powder (104).

[0117] Appendix 18. A step of depositing powder (104) to successively form a plurality of powder layers (114); forming a binder shell (116) by bonding selected areas of each of the plurality of powder layers (114) together before forming each subsequent layer of the plurality of powder layers (114) to form a plurality of shell layers (132) of the binder shell (116); The binder shell (116) surrounds a powder core (150), forming an additively manufactured object (130).

[0118] Clause 19. The additively manufactured object (130) of clause 18, wherein the process further comprises densifying the powder core (150) surrounded by the binder shell (116).

[0119] Appendix 20. The binder shell (116) a contour shape that corresponds to the final shape of the object (130); and having a thickness of less than 0.0625 inches; 19. The additively manufactured object (130) of claim 18, wherein the process further comprises sintering the object (130) to remove the binder (108) from the binder shell (116) and solidify the binder shell (116) and the powder (104) of the powder core (150).

[0120] Features, advantages, and characteristics described in one embodiment may be combined in any suitable manner in one or more other embodiments. Those skilled in the art will recognize that the embodiments described herein can be practiced without one or more of the specific features or advantages of a particular embodiment. In some cases, additional features and advantages may be observed in some embodiments and may not be present in all embodiments. Furthermore, while various embodiments of system 100, method 1000, and object 130 have been shown and described, variations will occur to those skilled in the art upon reading the specification. The present application encompasses such variations and is limited only by the scope of the claims.

Claims

1. A modeling platform and a powder deposition device configured to deposit powder onto the build platform to form multiple successive powder layers; a binder delivery device configured to deliver binder to selected areas of each successive layer of the plurality of powder layers such that successive binder shells are formed; a compaction device configured to densify a portion of the powder surrounded by the binder shell; a controller configured to operate the powder deposition device to deposit powder into a gap between a top surface of the binder shell and the portion of the densified powder to form a fill layer.

2. 10. The additive manufacturing system of claim 1, wherein the compaction device comprises a vibration mechanism coupled to the build platform and configured to compact the portion of the powder surrounded by the binder shell, the vibration mechanism comprising an ultrasonic vibration element configured to generate ultrasonic vibrations.

3. 3. The additive manufacturing system of claim 1 or 2, wherein the compaction device comprises a tamping mechanism configured to compress the portion of the powder surrounded by the binder shell, the tamping mechanism comprising a tamping head configured to compress the portion of the powder surrounded by the binder shell region by region in a sequential manner.

4. 4. The additive manufacturing system of claim 3, wherein the tamping mechanism comprises a plurality of tamping pins configured to simultaneously compress the entire portion of the powder surrounded by the binder shell.

5. the compaction device includes: a vibration mechanism coupled to the build platform and configured to compact the portion of the powder surrounded by the binder shell; and a tamping mechanism configured to compress the portion of the powder surrounded by the binder shell.

6. 1. A method of additively manufacturing an object, comprising: depositing powder to successively form a plurality of powder layers; successively forming binder shells by bonding selected areas of each of the plurality of powder layers before forming each subsequent layer of the plurality of powder layers, wherein the binder shells enclose a portion of the powder; densifying a portion of the powder surrounded by the binder shell; and depositing powder into the gap between the top surface of the binder shell and the densified powder portion to form a fill layer.

7. 7. The method of claim 6, wherein densifying the portion of the powder surrounded by the binder shell comprises applying vibrational energy to the portion of the powder surrounded by the binder shell.

8. 8. The method of claim 6 or 7, wherein densifying the portion of the powder surrounded by the binder shell comprises applying a compressive force to the portion of the powder surrounded by the binder shell.

9. 9. The method of claim 6, wherein successively forming the binder shells comprises supplying a binder to selected areas in each of the plurality of powder layers to successively form a plurality of shell layers of binder shells surrounding the portion of the powder surrounded by the binder shells.

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