Modified frame and recoating system

Abstract

The present disclosure generally relates to methods and apparatuses for additive manufacturing with improved powder distribution capabilities. Specifically, the methods and apparatuses of the present disclosure incorporate powder distribution vanes to improve the lateral deposition of powder from a hopper. Such methods and apparatuses have the potential to reduce powder overhead costs, mitigate associated health and environmental risks, and increase manufacturing efficiency.

Claims

1. A method of fabricating an object, comprising: (a) fusing at least a portion of a given layer of a powder to form at least one fused region; (b) providing a subsequent layer of the powder, the powder being delivered down through a recoater mechanism, the recoater mechanism having a plurality of planar vanes oriented at an angle greater than 0° relative to the vertical to spread the powder in a lateral direction toward an edge of a powder bed and allow powder to flow downward and in a first angled direction, wherein the planar vanes are incorporated into the recoater mechanism in order to direct powder flowing from a hopper or a reservoir to be deposited to the edge of the powder bed; and (c) repeating steps (a) and (b) until the object is formed.

2. The method of claim 1, wherein the recoater mechanism comprises a recoater arm.

3. The method of claim 2, wherein the recoater mechanism further comprises a recoater blade.

4. The method of claim 1, wherein the fusing comprises irradiating with a laser beam or with an electron beam.

5. The method of claim 1, wherein the fusing comprises binder jetting.

6. An apparatus for forming an object by additive manufacturing, comprising: a powder bed defined by a build plate, the build plate adapted to lower as the object is being made; a powder fusion mechanism for fusing portions of powder within the powder bed; and a recoater mechanism for providing a layer of powder, the recoater mechanism having two opposite ends and having a plurality of planar vanes oriented at an angle greater than 0° relative to the vertical to spread powder in a lateral direction toward an edge of the powder bed and allow powder to flow downward and in a first angled direction; wherein the planar vanes are incorporated into the recoater mechanism in order to direct powder flowing from a hopper or a reservoir to be deposited to the edge of the powder bed.

7. The apparatus of claim 6, wherein the recoater mechanism is held in place with a first support arm and a second support arm on opposite edges of the powder bed, the first and second support arms each having a generally horizontal surface near the respective edge of the powder bed, the horizontal surface adapted to support each end of the recoater mechanism.

8. The apparatus of claim 7, wherein the horizontal surface of each of the first and second support arms is unobstructed in a vertical direction, allowing attachment of the recoater mechanism by lowering it into place from a vertical direction while keeping the recoater mechanism level.

9. The apparatus of claim 6, wherein the recoater mechanism comprises a recoater arm.

10. The apparatus of claim 9, wherein the recoater arm comprises a recoater blade.

11. The apparatus of claim 6 wherein the powder fusion mechanism comprises an energy source.

12. The apparatus of claim 11, wherein the energy source is a laser source.

13. The apparatus of claim 11, wherein the energy source is an electron beam source.

14. The apparatus of claim 6, wherein the hopper is positioned atop the recoater mechanism.

15. The apparatus of claim 6, wherein the recoater mechanism further comprises a plurality of slits spanning a length of the recoater mechanism.

16. The apparatus of claim 15, wherein the plurality of slits are oriented at an angle relative to the vertical.

17. The apparatus of claim 6, wherein the recoater mechanism further comprises an insert nested in the recoater mechanism, the insert comprising the plurality of planar vanes.

18. The apparatus of claim 6, wherein the plurality of planar vanes are positioned along an entire length of the recoater mechanism.

19. The apparatus of claim 6, wherein the plurality of planar vanes are at a plurality of different angles from the vertical.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1A shows a schematic of an example of an apparatus for AM according to conventional methods.

(2) FIG. 1B shows a schematic of an example of a recoater arm for AM according to conventional methods.

(3) FIG. 1C shows an example of a support arm for AM according to conventional methods.

(4) FIG. 2A shows a schematic of an example of an apparatus for AM according to some aspects of the present disclosure.

(5) FIG. 2B shows a schematic of an example of a recoater arm for AM according to some aspects of the present disclosure.

(6) FIG. 2C shows an example of a support arm for AM according to some aspects of the present disclosure.

DETAILED DESCRIPTION

(7) The detailed description set forth below in connection with the appended drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well known components are shown in block diagram form in order to avoid obscuring such concepts.

(8) The present application is directed to methods and apparatuses for improving powder coating efficiency and coverage. As discussed above, an even powder coat across a DMLM platform is key for part quality. Powder distribution systems can be hindered by the effects of chamber pressurization and powder dynamics. Further, machine modifications may require powder to be distributed further than originally designed. These effects can result in a lack of powder at, for example, the edges of the plate. To combat this problem, vanes can be incorporated into recoater mechanisms in order to direct powder from a hopper atop the recoater to be deposited to the edge of the platform, thus improving powder distribution. Such powder distribution vanes may be built into a recoater arm directly or incorporated into an insert which may be nested into the recoater mechanism above deposition slits. The vanes may be constructed at various directions and angles from the vertical, to ensure that powder is deposited laterally or with at least a nonzero lateral component. Methods and apparatuses incorporating powder distribution vanes into recoater mechanisms, either by direct incorporation or by incorporation into inserts nested into the recoater mechanism, can reduce powder usage and keep powder distribution from becoming a limiting factor in production. Existing powder distribution systems and powder-based additive manufacturing methods and apparatuses may be leveraged in such machine expansion/modification efforts. The use of powder distribution vanes may increase the powder throughput capability of the recoating mechanism and may maximize the powder distribution capability of a given system. Vane application also allows for larger build volume (increase recoater effective width) with a minimum number of machine modifications. The vanes may utilize and leverage the potential energy of the powder height in the reservoir above the recoater to accomplish a wider layer of powder along the full distance of recoater travel without increasing other attributes of the recoater or machine interface.

(9) In addition, recoaters incorporating directional/angled powder distribution vanes may be used with modified support arms, such as modified support brackets, to accommodate wider powder hoppers and/or wider recoater arms.

(10) As used herein, the “vertical” direction refers to the z-direction, and “lowering” something refers to moving it downward vertically, i.e., in the z-dimension, such as in the negative z-direction.

(11) As used herein, “at an angle” is measured relative to the vertical, i.e., the z-axis, unless otherwise specified. In some aspects, the powder recoater mechanism may contain a plurality of vanes oriented at an angle to spread powder in a lateral direction toward the edges of a powder bed. In some such aspects, the angle from the vertical may be any angle greater than 0°, up to and including 90°, such as 10°, 20°, 30°, 40°, 50°, 60°, 70°, 80°, or any integer or range in between, as may be disclosed in other sections of this specification, which are incorporated into this paragraph by reference. In some aspects, all of the plurality of vanes in the recoater mechanism may be oriented at the same angle from the vertical. In some aspects, the plurality of vanes may be oriented at a plurality of different angles from the vertical.

(12) As used herein, the “lateral” direction refers to the horizontal direction, i.e., the xy-plane. In some aspects, the recoater mechanism may have a plurality of vanes oriented at an angle to spread powder in a lateral direction. In some such aspects, the spread of the powder has a component in the lateral direction, i.e., in the xy-plane, and also has a component in the vertical direction, i.e., the z-direction. In some of those aspects, the lateral component is greater than the vertical component. In other of those aspects, the lateral component is less than the vertical component.

(13) As used herein, “support arms” include, but are not limited to, brackets.

(14) FIG. 2A shows a schematic of an example of an apparatus for AM according to the present disclosure. Apparatus 240 may be similar in some aspects to apparatus 140 (FIG. 1A).

(15) In some aspects, the recoater mechanism, such as recoater arm 246, is a modified recoater arm, as shown in FIG. 2B. Recoater arm 246 may be similar in some aspects to recoater arm 146. Recoater arm 246 may contain a plurality of slits 268, which may be substantially vertical in some aspects. In some aspects, one or more of the plurality of slits 268 may comprise an opening that is at an angle from the vertical, such as to allow powder flow downward not only vertically (i.e., in direction 267) but also at various angles, e.g., in a first direction 273 and a second direction 274. In some aspects, an insert 280 may be nested in recoater arm 246, the insert 280 comprising a plurality of vanes 275 at one or more angles from the vertical. The plurality of vanes 275 may be generated by any suitable means known to those skilled in the art. Powder flowing from a powder hopper (not pictured) attached to the top of recoater arm 246 and insert 280, and through the plurality of vanes 275, may be spread more greatly in the x-dimension than powder flowing through the plurality of slits 168 (without directional vanes at an angle from the vertical) in recoater arm 146.

(16) In some aspects, all of the plurality of vanes 275 are at the same angle from the vertical. In other aspects, the plurality of vanes 275 may be at a plurality of different angles from the vertical. In some aspects, the plurality of vanes 275 may be positioned at or near the first end 265 and/or the second end 266 of the recoater arm 246. In some aspects, the plurality of vanes 275 may be positioned along the full length of the recoater arm 246. In some aspects, the insert 280 may be sized to serve as a standalone recoater mechanism, without nesting into a recoater arm 246.

(17) FIG. 2C shows an example of a modified support arm 269 for use with recoater arm 246 in apparatus 240. The support arm may include a mounting surface 279 which may comprise a substantially flat surface forming a plane that is substantially parallel with the x-y plane shown in FIG. 2C. The mounting surface may further include a series of mounting points 276A-C which may be through holes and/or threaded holes. The mounting points may be configured to line up with mounting points on the apparatus (e.g. at portion 177 shown in FIG. 1C). The support arm 269 may further include a cross brace 278 which may be substantially X-shaped. Recoater arm 246 may be held in place in apparatus 240 using the modified support arm 269, at attachment interface 271. In some aspects, the attachment interface 271 comprises a substantially flat surface forming a plane that is substantially parallel with the x-y plane shown in FIG. 2C, and side surfaces 290 which may be formed as substantially flat surfaces forming planes that are substantially perpendicular to the x-y plane. The attachment interface may further include at least one mounting point 277, which may be a through hole and/or threaded hole. The dimensions of the substantially flat surface 271, side surfaces 290, and/or mounting point(s) 277 may be dimensioned to accommodate ends 265, 266 of the recoater arm 246. When comparing the support arm shown in FIG. 1C with the modified support arm 269, the attachment interface 271 of the modified support arm 269 is moved such that the attachment interface 271 is closer to the mounting points 276A-C of the mounting surface 279 in the x direction. Thus, by moving the attachment interface 271 closer to the mounting points 276A-C in the x-direction, the modified support arm(s) may accommodate a recoater that is longer along an x-direction; allowing for a larger usable build area.

(18) The abovementioned advantage(s) of moving the attachment interface 271 closer to the mounting points 276A-C in the x-direction may be accomplished by removing cross brace 175 shown in FIG. 1C. Further, in the example shown in FIG. 2C, the angle of down braces 270 of the modified support arm is modified to be steeper than portions 169 of the support arm shown in FIG. 1C. To compensate for the removal of cross brace 175 shown in FIG. 1C, a cross brace (e.g. cross brace 278 shown in FIG. 2C) may be added to another portion of the support arm.

(19) This written description uses examples to disclose the invention, including the preferred embodiments, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention 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 have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims. Aspects from the various embodiments described, as well as other known equivalents for each such aspect, can be mixed and matched by one of ordinary skill in the art to construct additional embodiments and techniques in accordance with principles of this application.