Build table assembly and additive manufacturing system

Abstract

SOLUTION: This invention relates to a build table assembly (104) for supporting a component (102), the build table assembly including: a base (202) having an upper surface (302), a frame (110) extending from the upper surface (302) of the base (202), the frame defining an upper wall (310); a rim (112) formed on the upper wall (310) of the frame (110), and a plurality of fixture segments (114) positioned on the rim (112) opposite the upper wall (310) of the frame (110), the plurality of fixture segments (114) defining an arcuate build surface (116) on which the component is built (102), the plurality of fixture segments (114) spaced apart from one another.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates generally to directed energy deposition (DED) additive manufacturing systems and methods, and more particularly to DED systems and methods for reducing stress on a part during material deposition. [Background technology]

[0002] Additive manufacturing is a set of emerging technologies used to produce three-dimensional objects directly from digital models via additive processing, typically by depositing material layer-by-layer and bonding successive layers in place. DED is a type of additive manufacturing process used to produce new components and / or add additional material to existing components or repair existing components. With DED, components can be manufactured layer-by-layer using a directed stream of feed material from a deposition nozzle. DED machines use a focused energy source, such as a laser or electron beam, to melt a feed material and simultaneously deposit the molten material onto specific surfaces, where such molten material solidifies and fuses with other deposited materials to form the component layer-by-layer. Summary of the Invention [Means for solving the problem]

[0003] One aspect of the present disclosure is a build table assembly (104) for supporting a component (102), comprising: a base (202) having an upper surface (302); a frame (110) extending from the upper surface (302) of the base (202) and defining an upper wall (310); a rim (112) formed on the upper wall (310) of the frame (110); and a plurality of fixed segments (114) disposed on the rim (112) facing the upper wall (310) of the frame (110), the plurality of fixed segments (114) defining an arcuate build surface (116) on which the component (102) is built, the plurality of fixed segments (114) being spaced apart from one another. [Brief description of the drawings]

[0004] [Figure 1] FIG. 1 illustrates a schematic perspective view of an additive manufacturing system according to one or more embodiments shown and described herein. [Diagram 2] 2A-2C are schematic diagrams illustrating a perspective view of a build table assembly of the additive manufacturing system of FIG. 1 according to one or more embodiments shown and described herein. [Diagram 3] 3A-3C are schematic depictions of a perspective view of a stationary segment of the build table assembly of FIG. 2 according to one or more embodiments shown and described herein; [Figure 4] 3A-3C are schematic depictions of a partial cross-sectional view of the build table assembly of FIG. 2 according to one or more embodiments shown and described herein; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0005] The embodiments illustrated in the drawings are exemplary in nature and are not intended to limit the subject matter defined by the claims. The following detailed description of the exemplary embodiments can be understood when read in conjunction with the following drawings, in which like structure is indicated with like reference numerals and in which:

[0006] Reference will now be made in detail to the present embodiments of the disclosure, one or more examples of which are illustrated in the accompanying drawings. The detailed description uses numerical and letter designations to refer to features in the drawings. Like or similar designations in the drawings and description are used to refer to like or similar parts of the disclosure.

[0007] The terms "coupled," "fixed," "attached," and the like, unless otherwise specified in this specification, refer to both direct coupling, fixing, or attachment, and indirect coupling, fixing, or attachment through one or more intermediate components or features.

[0008] As used herein, "residual stress" refers to the magnitude and orientation of stresses that remain in a part after an additive manufacturing process, e.g., a combination of thermal stresses due to cooling after deposition and mechanical stresses due to the application of compressive forces.

[0009] The singular forms "a," "an," and the like include plural references unless the context clearly dictates otherwise.

[0010] For example, the term "at least one of" in the context of "at least one of A, B, and C" refers to A only, B only, C only, or any combination of A, B, and C.

[0011] As used in this application, the reference to any component (e.g., a layer, film, region, or plate) being on, in any manner, (e.g., positioned on, disposed on, disposed on, or formed on) another component indicates that the reference component is in contact with the other component or is above the other component through one or more intermediate components positioned between the reference component and the other component.

[0012] As used herein, connection references (e.g., attached, coupled, connected, and joined) may include intermediate members between and / or relative movement between the elements referenced by the connection reference, unless otherwise specified. Thus, a connection reference does not necessarily imply that the two elements are directly connected and / or in fixed relationship to one another. As used herein, stating that any part is "in contact with" another part is defined to mean that there are no intermediate parts between the two parts.

[0013] Unless otherwise indicated, descriptors such as "first," "second," "third," and the like are used herein without any attribution or otherwise indicating any sense of priority, physical order, arrangement in a list, and / or ordering, but are used merely as labels and / or arbitrary names to distinguish elements to facilitate understanding of the disclosed examples. In some instances, the descriptor "first" may be used to refer to an element in the detailed description, while the same element may be referenced in the claims by a different descriptor such as "second" or "third." In such instances, it should be understood that such descriptors are used, for example, only to clearly identify those elements that may otherwise share the same name.

[0014] Approximation language as used herein throughout the specification and claims is applied to modify any quantitative expression that may be permissibly varied without resulting in a change in the basic function to which it pertains. Thus, values ​​modified by terms such as "about," "approximately," and "substantially" should not be limited to the exact value specified. In at least some cases, the approximation language may correspond to the precision of an instrument for measuring a value, or the precision of a method or machine for building or manufacturing a component and / or system. For example, the approximation language may refer to being within a margin of 10 percent.

[0015] Throughout the specification and claims, range limitations are combinable and interchangeable, and such ranges include and are specific to all subranges contained therein, unless the context or language dictates otherwise. For example, all ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other.

[0016] Traditional additive manufacturing methods, such as DED systems, use a solid base, plate, or fixture attached to a machine by bolted joints or other suitable methods to which the part is assembled. When manufacturing large parts, for example, larger than 0.5 meters in diameter, isostatic fixtures that are movable in at least one axis are used to reduce residual stresses on the fixture and the part during manufacturing. These fixtures may include a plate with one or more, possibly three, slots through which bolts extend and secure the fixture to the machine. The slots allow the bolts to move within the slots and allow the fixture to expand and contract in at least one axis as the fixture and part are heated and subsequently cooled during the manufacturing process.

[0017] However, the cost of these plates for large parts can be high compared to the total cost of manufacturing the part, even considering that the fixture may be reused for additional parts. In addition, part ejection operations in which the part is removed from the fixture, such as removal of bolts, can induce a sudden release of residual stresses that result in cracking or failure of the part.

[0018] It is therefore desirable to provide a compliant fixture that includes a plurality of sectors arranged together to form a base on which a first layer of a part to be formed is deposited. In the embodiment described herein, the plurality of sectors form a ring on which a cylindrical part is built. As described in detail herein, the sectors are not physically connected to each other, and thus the layers of the part can expand and contract in certain directions during the manufacturing process. This movement allows for reducing excessive residual stress formation in the fixture and the part to accommodate thermal cycles during the manufacturing process.

[0019] The inventors of the present disclosure have developed an architecture for a fixture for components such as cylindrical components. In particular, the inventors have advanced a method for designing a fixture having given dimensions and material properties based on the dimensions and material properties of the component being manufactured. In the course of this implementation of studying / evaluating various fixture properties that may be feasible to optimally reduce residual stress formation in the component, the inventors unexpectedly discovered that a certain relationship exists between the tendency of the component to break and the ratio of stress between the component and the fixture. In particular, the inventors have confirmed that when the ratio of stress between the component and the fixture is less than 1.0, the component is less likely to fail, e.g., to deform and crack. By performing the calculations described in the following equation, it is possible to eliminate infeasible designs and utilize appropriate materials for the fixture segments 114 based on the particular component 102 to be built, which was previously unknown without the following equation. Such improper design of the fixture segments 114 results in excessive stress buildup in the component 102 and / or component failure during the manufacturing process. Furthermore, the inventors have confirmed that a particular ratio indicates to what extent the fixture is being utilized. For example, a smaller ratio indicates that the quality of the material forming the fastener is likely excessive and a lower quality, e.g., weaker material, may be used while still avoiding failure of the part, whereas a larger ratio indicates that the part is closer to failure and a stronger material forming the fastener should be used. This ratio thus identifies the optimal design for the fastener segment 114 given the accumulated stress levels within the component 102.

[0020] 1, a DED additive manufacturing system 100 (hereinafter system 100) is shown in accordance with one or more embodiments of the present invention. The system 100 is configured to build or build a component 102 from a feed material. The component 102 has an interior side 102a, an opposing exterior side 102b, and a layer or surface 102c to be built upon. In the illustrated example, the component 102 is a cylindrically shaped component, although in other examples the component 102 may have different geometric shapes.

[0021] As shown, the system 100 includes a build table assembly 104. In an embodiment, at least a portion of the build table assembly 104 is configured to rotate about a build table axis B of the build table assembly 104 that extends parallel to the Z axis of the coordinate axes to rotate a component 102 supported on the build table assembly 104. Thus, the build table assembly 104 is a rotating build table assembly 104. However, it should be understood that in other embodiments, the build table assembly 104 is fixed from rotating as the component 102 is being built.

[0022] Specifically, as described in more detail herein, the build table assembly 104 includes a base 106 supported on a platform 108, a frame 110 extending from the base 106 opposite the platform 108, and a rim 112 disposed on the frame 110 opposite the base 106. The build table assembly 104 further includes a plurality of fixed segments 114 disposed on the rim 112 of the frame 110 that surround the rim 112. The fixed segments 114 each define an arcuate build surface 116 upon which the components 102 are built and supported.

[0023] As described herein, any number of fixed segments 114 may be utilized, with the total number of fixed segments 114 depending on the length of each fixed segment 114 for a given length of the build surface 116. For example, in an embodiment in which each fixed segment 114 has a reduced length, a greater number of fixed segments 114 may be utilized. Alternatively, in an embodiment in which each fixed segment 114 is elongated, a lesser number of fixed segments 114 may be utilized. Each fixed segment 114 is secured to the rim 112 of the build table assembly 104, as described in more detail herein. However, the fixed segments 114 are not secured to one another. Thus, the fixed segments 114 are capable of moving radially during the manufacturing process to allow for expansion and contraction of the component 102. However, it should be understood that the fixed segments 114 may also, or alternatively, move in any direction during expansion and contraction. As illustrated, the frame 110, and thus the rim 112, has a cylindrical shape on which the component 102 is built. Thus, the component 102 has a cylindrical cross-section as well. The manner in which the fixed segment 114 is fixed to the rim 112 of the build table assembly 104 will be described in more detail herein.

[0024] In the illustrated embodiment, the base 106 of the build table assembly 104 rotates relative to the platform 108. Thus, an actuator 118 may be provided on either the platform 108 or the base 106 to rotate the build table assembly 104 clockwise or counterclockwise about the build table axis B. In the illustrated embodiment, the actuator 118 rotates the build table assembly 104 counterclockwise R about the build table axis B. Additionally, as described below, the actuator 118 rotates the build table assembly 104 at a variable number of rotations. In some embodiments, the base 106 is further configured to translate the build table assembly 104 vertically along the build table axis B.

[0025] The system 100 also includes a deposition assembly 120. The deposition assembly 120 has a deposition head 122 through which a stream of molten feed material can be deposited to produce the component 102. As described herein, the molten feed material is deposited or output from the deposition head 122 at a deposition rate. The deposition assembly 120 includes an arrangement for adjustably and movably supporting the deposition head 122. In the illustrated embodiment, the deposition assembly 120 includes a robot arm 124 including a plurality of links 126 that can be articulated relative to one another to adjust the position of the deposition head 122, which in the illustrated embodiment is supported on a distal-most link 128 of the plurality of links 126. It should thus be understood that the deposition head 122 and the build table assembly 104 are movable relative to one another. For example, the robot arm 124 can include one or more actuators that rotate the links 126, 128 of the robot arm 124 relative to one another to move the robot arm 124 and the deposition head 122 supported thereon relative to the build table assembly 104. It will be appreciated that the robotic arm 124 may have a variety of other configurations for moving and adjusting the position of the deposition head 122 in multiple degrees of freedom without departing from this disclosure.

[0026] The deposition assembly 120 includes an energy source 130 and a material source 132. The material source 132 is configured to deliver a feed material (e.g., a metal or polymer-based wire) to the deposition head 122 where it is deposited on the build table assembly 104. In the illustrated embodiment, the material source 132 is a material spool and feeder system configured to deliver a wire 134 to the deposition head 122. Thus, the material source 132 can accommodate the wire 134 that is fed to the deposition head 122. For example, the wire 134 can be routed from outside the robot arm 124 to the deposition head 122 or through an internal cavity of the robot arm 124 that connects to the deposition head 122. In an embodiment, the wire 134 can be a metal or polymer-based wire. In other embodiments, rather than a material spool and feeder system configured to deliver the wire 134, the material source 132 can include a pressurized powder source that delivers a pressurized flow of powder feed material to one or more material delivery devices (e.g., nozzles, valves, etc.) of the deposition head 122. Any suitable feed material that can be used in a DED process can be used consistent with this disclosure.

[0027] The energy source 130 can take a variety of forms depending on the embodiment. In the illustrated example, the energy source 130 is a plasma transferred arc heat source. In other examples, the energy source 130 can include a laser source and optics configured to direct a laser beam having a desired energy density to the build surface 116 of the stationary segment 114. In some examples, the energy source 130 can include an electron emitter connected to a power source and at least one focusing coil configured to direct the electron beam to the component 102 being built on the build surface 116 of the stationary segment 114. In such an embodiment, the build table assembly 104 can be located under vacuum or in a build chamber (not shown) having a reduced oxygen environment. However, the energy source 130 can take a variety of other forms, such as a plasma source, an electron beam source, a resistive heater, etc.

[0028] The system 100 may include any number of energy sources and material sources according to the present disclosure. Additionally, the feed material from the material source 132 may be delivered to the deposition head 122 in a variety of ways for discharge onto the build table assembly 104. For example, in an embodiment, a wire 134 from the material source 132 may be split into two or more material feeds that are delivered through the robot arm 124 to the deposition head 122. Each material feed may exit the deposition head 122 at a separate delivery nozzle. Additionally, multiple energy sources, such as, for example, an electric arc heat source and a laser, may be utilized to form the same molten pool.

[0029] During operation, one or more streams of feed material are fed into the path of the energy beam from the energy source 130 and are emitted by the deposition head 122 as a stream of molten feed material. In particular, at the overlap point between the energy beam and the stream of feed material where the energy beam has the required energy density, the energy can heat the feed material to a sufficient degree to form a molten pool on the build surface 116. The molten feed material may be continuously fed through and deposited from the deposition head 122, such that the molten pool forms a pattern corresponding to the motion pattern of the deposition head 122 and the build table assembly 104. The motion of the deposition head 122 and the build table assembly 104 may be determined based on the desired shape of the component 102 to be built, such that as the molten pool cools, the feed material solidifies to form part of the component 102. For example, as the deposition head 122 deposits the molten pool, the rotation of the build table assembly 104 about the build table axis B results in a circular shaped stream of molten feed material that builds up on itself and builds a cylindrical shaped component, such as the component 102, as the build table assembly 104 continuously rotates over time. Additionally, the robotic arm 124 can position the deposition head 122 radially toward or away from the build table axis B to create non-circular components having various sizes and diameters, as shown.

[0030] The system 100 further includes a compression rig 140. The compression rig 140 is disposed proximate to the deposition assembly 120 and is operable to continuously apply a compressive load to the deposited feed material forming the component 102. As described herein, the compression rig 140 is configured to apply a compressive load to the component 102 (e.g., a compression phase) during or simultaneously with a deposition phase in which the deposition assembly 120 deposits a stream of molten feed material to build the component 102. In the illustrated embodiment, the compression rig 140 includes at least one actuator and a load source 144, as described further below.

[0031] In general, the at least one actuator is configured to move and manipulate the orientation of the load source 144 relative to the portion of the component 102 to which the compressive load is applied. The load source 144 applies a force to the deposited material to introduce a desired strain level into the deposited layer and / or improve the mechanical properties of the component 102.

[0032] As described herein, in embodiments, the robot arm 124 is operable to position the deposition head 122 in close proximity to the load source 144 and / or the compression rig 140 is operable to position the load source 144 in close proximity to the deposition head 122. For example, the spacing between the load source 144 and the deposition head 122 can be increased if cold rolling is intended by rotating the build table assembly 104 counterclockwise. In this manner, the deposition head 122 can be operated to deposit molten feed material into the molten pool such that the load source 144 applies a compressive load to the component 102, and the load source 144 follows the deposition head 122, with the load source 144 applying a load to the previously deposited material a short time thereafter depending on the rotational speed of the build table assembly 104. Thus, the compression rig 140 can apply a compressive load to the component 102 at the same time that the deposition head 122 creates a molten pool at least proximate to the molten pool of the component 102. This not only reduces machine cycle times, but also allows the compressive load to be applied to the component 102 at a consistent and predetermined temperature suitable for imparting a wrought quality to the component 102. However, as discussed herein, the build table assembly 104 may be used separately and independently of the robotic arm 124 and compression rig 140.

[0033] In an embodiment, the system 100 may further include a controller 150. The controller 150 may be communicatively coupled to the build table assembly 104, the deposition assembly 120, and / or the compression rig 140. Thus, the controller 150 may be in communication with and control the operation of the base 106, the robotic arm 124, and / or the compression rig 140. For example, the controller 150 may include a processor and a memory device that stores computer readable instructions that, when executed by the processor, dynamically control a rotational direction and / or a rotational speed of the build table assembly 104 about the build table axis B, a vertical translation of the build table assembly 104 along the build table axis B, a position and orientation of the deposition head 122 in space via the robotic arm 124, a position and orientation of the load source 144 in space, and / or a magnitude of a compressive load applied by the load source 144. The controller 150 may also be configured to control the feed rate of the feed material supplied to the deposition head 122 and / or the deposition rate at which the stream of molten feed material is output from the deposition head 122.

[0034] In an embodiment, the system 100 can have various sensors configured to communicate with the controller 150, which can utilize data from the various sensors to control the operation of the build table assembly 104, the deposition assembly 120, and / or the compression rig 140 as may be desired to fabricate a particular component 102.

[0035] In the illustrated embodiment, the deposition head 122 deposits feed material to fabricate the component 102 on the build table assembly 104, which rotates in a counterclockwise direction R about the build table axis B. As the build table assembly 104 continues to rotate the component 102 in the counterclockwise direction R, the feed material previously deposited by the deposition head 122 encounters the load source 144 after being deposited from the deposition head 122. Thus, in the illustrated embodiment, the deposition head 122 acts on a particular portion of the component 102 before the load source 144 acts on that particular portion of the component 102, and similarly, the load source 144 acts on a particular portion of the component 102 after the deposition head 122 acts on that particular portion of the component 102. In other words, in the illustrated embodiment, as the build table assembly 104 rotates in the counterclockwise direction R, the deposition head 122 is positioned in front of the load source 144, and the load source 144 is positioned behind the deposition head 122.

[0036] In an embodiment, the compression rig 140 may include a slidable support structure 210 configured to slide laterally in a Y-axis direction relative to the base 202. In an embodiment, the compression rig 140 may include a slidable positioning structure 220 configured to slide vertically in a Z-axis direction relative to the slidable support structure 210. In an embodiment, the compression rig 140 includes an adjustable support member 230 that supports a compression head 246 that includes the load source 144. The adjustable support member 230 is coupled to the slidable positioning structure 220 and configured to allow relative rotation of the compression head 246.

[0037] In an embodiment, the load source 144 comprises a number of rollers configured to apply a compressive load to the component 102 at different portions of the component 102. The compression head 246 is configured to rotatably hold the multiple rollers at different orientations to roll on specific portions of the component 102.

[0038] 2, the build table assembly 104 is shown in more detail, separate from the platform 108 and the component 102 shown in FIG. 1. As described herein, in more detail, the build table assembly 104 includes a base 106 having an upper surface 302 and an opposing lower surface 304. It should be understood that the lower surface 304 of the base 106 may be provided on the platform 108 (FIG. 1) and, in an embodiment, may be rotatably and translatably secured thereto via an actuator 118 such that the base 106, and thus other components of the build table assembly 104 coupled to the base 106, may rotate and translate vertically relative to the platform 108. As shown in FIG. 2, the base 106 has a circular geometric shape. However, it should be understood that the base 106 may have any suitable geometric shape other than that shown herein.

[0039] The build table assembly 104 further includes a frame 110 extending from the top surface 302 of the base 106 in a direction away from the platform 108 ( FIG. 1 ). The frame 110 includes an inner surface 306 and an outer surface 308 opposite the inner surface 306. The frame 110 further includes a top wall 310 disposed opposite the top surface 302 of the base 106. The distance between the inner surface 306 and the outer surface 308 of the frame 110 defines a frame thickness. A plurality of recesses 312 are formed in the outer surface 308 of the frame 110 and extend radially toward the inner surface 306 of the frame 110. The recesses 312 define fins 314 extending between the top wall 310 of the frame 110 and the base 106. In an embodiment, the recesses 312 each have the same width such that the fins 314 are equidistantly spaced from one another along the entire circumference of the outer surface 308 of the frame 110. 2, frame 110 has a generally circular geometric shape, even though recesses 312 are formed in outer surface 308 of frame 110. However, it should be understood that frame 110 may have any suitable geometric shape other than that shown herein.

[0040] The build table assembly 104 further includes a rim 112 disposed on and completely surrounding the top wall 310 of the frame 110. The rim 112 includes an inner surface 316 and an outer surface 318 opposite the inner surface 316. The rim 112 further includes an upper surface 320 opposite the top wall 310 of the frame 110, the upper surface 320 extending between the outer surface 318 and the inner surface 316 of the rim 112. The distance between the inner surface 316 and the outer surface 318 of the rim 112 defines a rim thickness. As shown in FIG. 2, the rim thickness is less than the thickness of the frame. In an embodiment, the rim 112 and the top wall 310 of the frame 110 are formed as a one-piece monolithic structure. In other embodiments, the rim 112 is removably secured to the top wall 310 of the frame 110. As shown in FIG. 2, the rim 112 has a circular geometric shape. However, it should be understood that the rim 112 may have any suitable geometric shape other than those shown herein.

[0041] The build table assembly 104 further includes a number of fastening segments 114 disposed on the rim 112. As shown in FIG. 2, the build table assembly 104 includes four fastening segments 114 formed to surround the rim 112. However, it should be understood that the build table assembly 104 may include any suitable number of fastening segments 114 based on the circumference of the rim 112. Additionally, as shown in FIG. 2 and discussed in more detail herein, each fastening segment 114 is secured to the rim 112 by a number of fasteners 322. Specifically, each fastening segment 114 includes three or more fasteners 322, such as, for example, four fasteners 322 received within the corresponding fastening segment 114, as shown in FIG. 2. However, it should be understood that any suitable number of fasteners 322 may be utilized to secure each fastener segment 114 to the rim 112 and the frame 110, such as, for example, three fasteners 322, five fasteners 322, and more than five fasteners 322.

[0042] As shown in FIG. 3, an individual fixed segment 114 is shown. It should be understood that each fixed segment 114 may include identical structures. Accordingly, like parts of each fixed segment 114 are indicated with like reference numerals. Each fixed segment 114 has an arcuate shape and includes an inner surface 324 that defines a fixed thickness, and an outer surface 326 opposite the inner surface 324. The fixed thickness of each fixed segment 114 may also be defined by the difference between an inner radius of the fixed segment 114 measured between the build table axis B (FIG. 2) and the inner surface 324 of the fixed segment 114, and an outer radius of the fixed segment 114 measured between the build table axis B (FIG. 2) and the outer surface 326 of the fixed segment 114. The fixed segment 114 further includes an upper surface 328 and a lower surface 330 opposite the upper surface 328. The upper surface 328 and the lower surface 330 extend between the inner surface 324 and the outer surface 326.

[0043] The fixed segment 114 includes a plurality of cavities 332 formed therein. As shown, the fixed segment 114 has four cavities 332 formed therein. However, it should be understood that any suitable number of cavities 332 may be formed in the fixed segment 114, e.g., three cavities 332, five cavities 332, and more than five cavities 332. Specifically, the number of cavities 332 formed in the fixed segment 114 corresponds to the number of fasteners 322 ( FIG. 2 ) utilized to secure the fixed segment 114 to the rim 112 and frame 110. In an embodiment, each cavity 332 has an elliptical shape and defines a ledge 338. As shown, a hole 339 is formed in each cavity 332 of the fixed segment 114 extending from the ledge 338 through the underside 330 of the fixed segment 114 to allow a respective fastener 322 to extend therethrough.

[0044] 4, a cross-sectional view of the fixing segment 114 disposed on the rim 112 is shown. As shown, the fixing segment 114 has a fixing thickness substantially equal to the rim thickness. As shown in FIG. 4, an upper nut 340 is disposed within each cavity 332 formed in the fixing segment 114. The upper nut 340 is positionable within the cavity 332 through the outer surface 326 of the fixing segment 114. A hole 348 is formed in the upper nut 340 to allow the fastener 322 to extend therethrough. An internal thread 349 is formed within the hole 348 of the upper nut 340. In an embodiment, the upper nut 340 has a spherical lower surface 341 that provides an increased thickness at the center of the upper nut 340. In such an embodiment, an upper washer 343 is disposed between the upper nut 340 and the ledge 338 of the cavity 332. The upper washer 343 has a spherical upper surface 345 that provides a reduced thickness in the center of the upper washer 343 that corresponds to the taper of the spherical lower surface 341 of the upper nut 340. Thus, the spherical upper surface 345 of the upper washer 343 mates with the spherical lower surface 341 of the upper nut 340. The presence of the upper washer 343 having a spherical upper surface 345 that mates with the spherical lower surface 341 of the upper nut 340 reduces shear loads on the fastener 322 itself being pulled and / or compressed. However, it should be understood that in embodiments, either or both of the lower surface 341 of the upper nut 340 and the upper surface 345 of the upper washer 343 may have any suitable geometric shape, such as, for example, a conical or frusto-conical shape as opposed to a spherical shape.

[0045] 4, the fastener 322 includes a shaft 350 having a first end 352, a second end 354 opposite the first end 352, and a body 356 extending between the first end 352 and the second end 354. The body 356 of the shaft 350 has a shaft diameter. The shaft 350 has male threads 358 disposed at the first end 352 for engaging the female threads 349 of the upper nut 340. Thus, the first end 352 of the shaft 350 is received within and engages the female threads 349 of the upper nut 340 to secure the first end 352 of the shaft 350 to the fixed segment 114. The shaft 350 of the fastener 322 extends through a channel 360 formed in the rim 112 and a channel 362 formed in the top wall 310 of the frame 110. Thus, the channel 360 formed in the rim 112 is coaxial with the channel 362 formed in the top wall 310 of the frame 110. The channel 360 formed in the rim 112 and the channel 362 formed in the top wall 310 of the frame 110 have channel diameters that are greater than the shaft diameter.

[0046] The second end 354 of the fastener 322 defines a head 355 having a diameter larger than the shaft diameter. The second end 354 terminates in a corresponding recess 312 formed in the outer surface 308 of the frame 110. In an embodiment, a lower flat washer 366 is provided between the head 355 of the fastener 322 and the upper wall 310 of the frame 110. Additionally, in an embodiment, a lower washer 357 is provided between the head 355 of the fastener 322 and the lower flat washer 366. The lower washer 357 can include a first lower washer portion 359 and a second lower washer portion 361. The first lower washer portion 359 includes a flat upper surface 363 and a spherical lower surface 365 opposite the flat upper surface 363. The spherical lower surface 365 of the first lower washer portion 359 provides a reduced thickness at a center of the first lower washer portion 359. The second lower washer portion 361 includes a flat lower surface 367 and a spherical upper surface 369 opposite the flat lower surface 367. The spherical upper surface 369 of the second lower washer portion 361 increases the thickness at the center of the second lower washer portion 361. Thus, the spherical lower surface 365 of the first lower washer portion 359 mates with the spherical upper surface 369 of the second lower washer portion 363, and the presence of the first lower washer portion 361 having the spherical lower surface 365 that mates with the spherical upper surface 369 of the second lower washer portion 363 reduces shear loads on the fastener 322 itself being pulled and / or compressed. However, it should be understood that in embodiments, either or both of the lower surface 365 of the first lower washer part 358 and the upper surface 369 of the second lower washer part 361 may have any suitable geometric shape, such as, for example, a conical or frusto-conical shape as opposed to a spherical shape.

[0047] As shown in FIG. 4 and discussed herein, the shaft diameter is smaller than the channel diameter. Thus, when the fastener 322 remains fixed to the fixed segment 114 at the first end 352 of the shaft 350 received in the upper nut 340, the fastener 322 is able to move radially relative to the rim 112 and the frame 110 throughout the manufacturing process of the component 102. As described herein, during the manufacturing process, the component 102 expands radially. Thus, the fixed segment 114 is configured to shift radially relative to the rim 112 to accommodate the expansion of the component 102. To ensure that the fixed segment 114 remains fixed to the rim 112 and the frame 110, the first end 352 of the shaft 350 is held within a cavity 332 formed in the corresponding fixed segment 114, while the shaft 350 remains radially movable within the channel 360 of the rim 112 and the channel 362 of the frame 110. The amount of radial movement permitted by the fixed segment 114 relative to the rim 112 is determined by the difference between the shaft diameter and the channel diameter, as well as the frictional forces between the components resulting from the locking force and the coefficient of friction. In other words, the greater the difference between the channel diameter and the shaft diameter, the greater the radial movement of the fixed segment 114 relative to the rim 112.

[0048] As alluded to above, the inventors have unexpectedly discovered that a relationship exists between the relative ratio of stresses between the component 102 and the fixed segment 114. Specifically, the inventors have discovered that the ratio of stresses between the component 102 and the fixed segment 114 is indicative of whether part failure is more likely to occur. In particular, the inventors have determined that part failure is less likely to occur when the ratio is less than 1.0. Furthermore, the inventors have discovered that the ratio of stresses between the component 102 and the fixed segment 114 is indicative of whether the material forming the fixed segment 114 is underutilized such that it would be beneficial from a cost standpoint to use a lower quality material for the purpose of forming the particular component 102. As a result, improved part quality and material efficiency have been achieved.

[0049] More specifically, a particular ratio between the component 102 stress and the fixed segment 114 stress is determined according to equation (1).

number

[0050] In the above equation (1), Rs represents the ratio of stress between the component 102 and the fixed segment 114, S_p represents the stress accumulated in the tangential part of the component 102, and YS fixture represents the yield stress of the fixed segment 114, and YS fastener represents the yield stress of the fastener 322, and YS upper_nut represents the yield stress of the upper nut 340. In the above formula (1),

number

[0051] First, the component sector area (A component_sector ) to determine

number

[0052] In the above equation (2), R out represents the outer radius of the fixed segment 114, and R in represents the inner radius of the fixed segment 114, and N fixtures represents the total number of fixed segments 114. As described herein, the outer and inner radii of the fixed segments 114 are measured from the build table axis B of the build table assembly 104.

[0053] Component stresses are determined by Finite Element Method (FEM) analysis. Integral forces in kilonewtons (kN)

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[0054] It should be understood that the division by "1000" in the formulas above and below is merely to maintain consistent units.

[0055] Fixed yield stress YS fixture represents a known value based on the properties of the material forming the fixed segment 114. In addition, min(YS fixture ) represents the minimum fixed yield stress, specifically, the minimum yield stress of any portion of the fixed segment 114. The minimum yield stress (min(YS fixture ) integral

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[0056] Sum of fastener yield stresses Σ N (Y.S. fastener ) is determined according to equation (5). JPEG2025014103000009.jpg30144

[0057] Fastener Yield Stress (YS fastener ) represents a known value based on the properties of the material from which the fastener is made. In addition, the radius (Radius) of the fastener 322 fastener ) is equal to half the diameter of the shaft 350 of the fastener 322, and N fasteners represents the total number of fasteners 322 associated with each fixation segment 114.

[0058] In addition, the sum of the upper nut yield stresses Σ N (Y.S. upper_nut ) is determined according to equation (6).

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[0059] In an embodiment, the upper nut 340 and the fastener 322 may be formed from the same material. In this embodiment, the fastener yield stress (YS upper_nut ) is equal to the upper nut yield stress.

[0060] Therefore, the solution to equation (1) is equal to the solution to equation (4) divided by the sum of the solutions to equations (4), (5), and (6). In other words, the ratio of the stresses between the component 102 and the fixed segment 114 (Rs) is the integral of the component stresses:

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[0061] As described herein, the inventors have discovered that a solution to equation (1), e.g., a ratio of stresses (Rs) less than 1.0, ensures that component failure is unlikely. This is determined based on numerous tests in which parameters are varied where failure of the above equation results in component failure (e.g., cracking of the component) and satisfaction of the above equation does not result in component failure. More specifically, the inventors have discovered a specific range of ratios of stresses (Rs) to ensure that the material forming the stationary segment 114 is fully utilized. Specifically, the inventors have discovered that a ratio (Rs) of 0.2 or greater and 0.8 or less is sufficient to cover all feasible designs of the component 102. More specifically, the inventors have discovered that applying a ratio (Rs) of 0.3 or greater and 0.5 or less ensures that the material forming the stationary segment 114 is not over- or under-utilized given the parameters of the component 102.

[0062] Although specific features of various embodiments may be shown in some drawings and not in others, this is for convenience only, and in accordance with the principles of the present disclosure, any feature of a drawing may be referenced and / or claimed in combination with any feature of any other drawing.

[0063] This specification uses examples to disclose the disclosure, including the best mode, and also enables any person skilled in the art to practice the disclosure, including making and using any device or system, and practicing any incorporated methods. The patentable scope of the disclosure is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they contain structural elements that do not differ from the literal language of the claims, or if they contain equivalent structural elements that do not differ substantially from the literal language of the claims.

[0064] Further aspects are provided by the subject matter of the following sections.

[0065] A build table assembly for supporting a component, comprising: a base having an upper surface; a frame extending from the top surface of the base and defining a top wall; a rim formed on the top wall of the frame; a plurality of fixing segments disposed on the rim facing the top wall of the frame; Including, a plurality of said fixture segments defining an arcuate build surface along which said component is built; The plurality of fixed segments are spaced apart from one another. Build table assembly.

[0066] Each fixed segment of the plurality of fixed segments comprises: The inside and an outer surface opposite the inner surface; and The top surface and a lower surface opposite the upper surface; a plurality of spaced apart cavities extending through the outer surface and the lower surface; Including, Build table assembly as shown above.

[0067] The plurality of fixed segments includes four fixed segments. Any of the build table assemblies listed above.

[0068] a plurality of upper nuts, each upper nut of the plurality of upper nuts being received within a corresponding one of the plurality of cavities; a plurality of fasteners for fastening each of the plurality of fastening segments to the rim, each of the plurality of fasteners engaging a corresponding upper nut to retain the plurality of fasteners within a corresponding cavity; 20. The build table assembly of claim 19, further comprising:

[0069] 13. The build table assembly of any of the above, wherein each cavity has an oval shape.

[0070] each fastener of the plurality of fasteners extends through a corresponding channel formed in the frame; a diameter of the channel is greater than a diameter of the fastener to permit radial outward movement of the plurality of fixation segments relative to the frame; Any of the build table assemblies listed above.

[0071] A plurality of recesses are formed in an outer surface of the frame to define a plurality of fins; each fastener of the plurality of fasteners terminating within a corresponding recess of the plurality of recesses; Any of the build table assemblies listed above.

[0072] a ratio of stress between the component and the plurality of fixation segments is less than 1.0;

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[0073] a ratio of stress between the component and the plurality of fixing segments is greater than or equal to 0.2 and less than or equal to 0.8; Any of the build table assemblies listed above.

[0074] a ratio of stress between the component and the plurality of fixing segments is greater than or equal to 0.3 and less than or equal to 0.5; Any of the build table assemblies listed above.

[0075] The platform, a build table assembly mounted on the platform, the build table assembly being rotatable relative to the platform about a vertical axis of the build table assembly; a deposition assembly having a deposition head for depositing molten feed material onto a plurality of said stationary segments; Including, The build table assembly includes: a base having an upper surface; a frame extending from the top surface of the base and defining a top wall; a rim formed on the top wall of the frame; a plurality of spaced apart stationary segments disposed on the rim opposite the top wall of the frame and defining an arcuate build surface on which the component is built; Including, Additive manufacturing systems to manufacture components.

[0076] Each fixed segment of the plurality of fixed segments comprises: The inside and an outer surface opposite the inner surface; and The top surface and a lower surface opposite the upper surface; and a plurality of spaced apart cavities extending through the outer surface and the lower surface; Including, Any of the additive manufacturing systems listed above.

[0077] The plurality of fixed segments includes four fixed segments. Any of the above additive manufacturing systems.

[0078] a plurality of upper nuts, each upper nut of the plurality of upper nuts being received within a corresponding one of the plurality of cavities; a plurality of fasteners for fastening each of the plurality of fastening segments to the rim, each of the plurality of fasteners engaging a corresponding upper nut to retain the plurality of fasteners within a corresponding cavity; Any of the above additive manufacturing systems further comprising:

[0079] Any of the above additive manufacturing systems, wherein each cavity has an elliptical shape.

[0080] each fastener of the plurality of fasteners extends through a corresponding channel formed in the frame; a diameter of the channel is greater than a diameter of the fastener to permit radial outward movement of the plurality of fixation segments relative to the frame; Any of the additive manufacturing systems listed above.

[0081] A plurality of recesses are formed in an outer surface of the frame to define a plurality of fins; each fastener of the plurality of fasteners terminating within a corresponding recess of the plurality of recesses; Any of the additive manufacturing systems listed above.

[0082] a ratio of stress between the component and the plurality of fixation segments is less than 1.0;

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[0083] a ratio of stress between the component and the plurality of fixing segments is greater than or equal to 0.2 and less than or equal to 0.8; Any of the additive manufacturing systems listed above.

[0084] Any of the above additive manufacturing systems, wherein a ratio of stress between the component and the plurality of fixed segments is greater than or equal to 0.3 and less than or equal to 0.5.

[0085] A frame, a plurality of spaced apart fastening segments provided on the frame and defining an arcuate build surface on which the component is built; Including, a ratio of stress between the component and the plurality of fixation segments is less than 1.0;

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[0086] a ratio of stress between the component and the plurality of fixing segments is greater than or equal to 0.2 and less than or equal to 0.8; Any of the build table assemblies listed above.

[0087] Any of the preceding build table assemblies, wherein a ratio of stress between said component and a plurality of said fixed segments is greater than or equal to 0.3 and less than or equal to 0.5.

Claims

1. A build table assembly (104) for supporting a component (102), comprising: a base (202) having an upper surface (302); a frame (110) extending from the top surface (302) of the base (202) and defining a top wall (310); a rim (112) formed on the top wall (310) of the frame (110); a plurality of fixed segments (114) disposed on the rim (112) facing the top wall (310) of the frame (110); Including, a plurality of said stationary segments (114) defining an arcuate build surface (116) upon which said component (102) is built; The plurality of fixed segments (114) are spaced apart from one another. Build table assembly (104).

2. Each of the plurality of fixed segments (114) comprises: An inner surface (324); an outer surface (326) opposite said inner surface (324); An upper surface (328); a lower surface (330) opposite said upper surface (328); a plurality of spaced apart cavities (332) extending through said outer surface (326) and said lower surface (330); Including, The build table assembly (104) of claim 1.

3. The plurality of fixed segments (114) includes four fixed segments (114). The build table assembly (104) of claim 2.

4. a plurality of upper nuts (340), each of said plurality of upper nuts (340) being received within a corresponding one of said plurality of cavities (332); a plurality of fasteners (322) for securing each of the plurality of fastening segments (114) to the rim (112), each of the plurality of fasteners (322) engaging a corresponding upper nut (340) to retain the plurality of fasteners (322) within a corresponding cavity (332); The build table assembly (104) of claim 2 or claim 3, further comprising:

5. The build table assembly (104) of claim 3 or claim 4, wherein each cavity (332) has an elliptical shape.

6. Each fastener (322) of the plurality of fasteners (322) extends through a corresponding channel (360) formed in the frame (110); a diameter of the channel (360) is greater than a diameter of the fastener (322) to permit radial outward movement of the plurality of fixed segments (114) relative to the frame (110); The build table assembly (104) of any one of claims 3 to 5.

7. A plurality of recesses (312) are formed in an exterior surface (326) of the frame (110) defining a plurality of fins (314); each fastener (322) of the plurality of fasteners (322) terminates within a corresponding recess (312) of the plurality of recesses (312); The build table assembly (104) of claim 6.

8. a ratio of stress between the component (102) and the plurality of fixation segments (114) is less than 1.0; [0010] is defined by S_p represents the stress accumulated in the tangential part of said component (102); Y.S. ｆｉｘｔｕｒｅ represents the yield stress of the fixed segment (114); Y.S. ｆａｓｔｅｎｅｒ represents the yield stress of the plurality of fasteners (322); Y.S. ｕｐｐｅｒ＿ｎｕｔ represents the yield stress of the upper nut (340); The build table assembly (104) of any one of claims 1 to 7.

9. a ratio of stress between the component (102) and the plurality of fixation segments (114) is greater than or equal to 0.2 and less than or equal to 0.8; The build table assembly (104) of claim 8.

10. a ratio of stress between the component (102) and the plurality of fixation segments (114) is greater than or equal to 0.3 and less than or equal to 0.5; The build table assembly (104) of claim 8 or claim 9.

11. A platform (108); a build table assembly (104) according to any one of claims 1 to 10 mounted on said platform (108), said build table assembly (104) being rotatable relative to said platform (108) about a vertical axis of said build table assembly (104); a deposition assembly (120) having a deposition head that deposits molten feed material onto a plurality of stationary segments (114); Including, An additive manufacturing system (100) for manufacturing a component.

12. a ratio of stress between the component (102) and the plurality of fixation segments (114) is less than 1.0; [0025] is defined by S_p represents the stress accumulated in the tangential part of said component (102); Y.S. ｆｉｘｔｕｒｅ represents the yield stress of the fixed segment (114); Y.S. ｆａｓｔｅｎｅｒ represents the yield stress of the plurality of fasteners (322); Y.S. ｕｐｐｅｒ＿ｎｕｔ represents the yield stress of the upper nut, The additive manufacturing system (100) of any one of claims 1 to 11.

13. a ratio of stress between the component (102) and the plurality of fixed segments (114) is greater than or equal to 0.2 and less than or equal to 0.8; The additive manufacturing system (100) of claim 12.

14. The additive manufacturing system of claim 12 or 13, wherein a ratio of stress between the component (102) and the plurality of fixed segments (114) is greater than or equal to 0.3 and less than or equal to 0.5.

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