Techniques for depowdering additively fabricated parts through fluid immersion and related systems and methods

Patent metadata

Field	Value
Publication number	US-2021060651-A1
Application number	US-202016999210-A
Country	US
Kind code	A1
Filing date	Aug 21, 2020
Priority date	Aug 23, 2019
Publication date	Mar 4, 2021
Grant date	—

Abstract

Techniques for depowdering in additive fabrication are provided. According to some aspects, techniques are provided that separate powder from additively fabricated parts through liquid immersion of the parts. Motion of the liquid, such as liquid currents, may dislodge or otherwise move powder away from additively fabricated parts to which it is adhered or otherwise proximate to. The liquid may also provide a vehicle to carry away powder from the additively fabricated parts. Removed powder may be filtered or otherwise separated from the liquid to allow recirculation of the liquid to the parts and/or to enable re-use of the powder in subsequent additive fabrication processes. Techniques for depowdering through liquid immersion may be automated, thereby mitigating challenges associated with manual depowdering operations.

First claim

What is claimed is:

1 . A method of depowdering additively fabricated parts comprising bound metal powder and having unbound metal powder on their surface, the method comprising:
arranging one or more additively fabricated parts within a container containing a liquid, the container coupled to at least one inlet through which the liquid flows into the container, and the container coupled to at least one outlet through which the liquid flows out of the container; generating, using at least one source of agitation, currents within the liquid in the container; conveying, by the generated liquid currents, unbound metal powder away from the one or more additively fabricated parts; and filtering, using a filtration device coupled to the at least one outlet of the container, at least some of the conveyed unbound metal powder from the liquid that flows out of the container.

2 . The method of claim 1 , wherein the one or more additively fabricated parts are arranged on a tray within the container.

3 . The method of claim 2 , wherein the tray comprises a plurality of perforations and wherein conveying the unbound metal powder away from the one or more additively fabricated parts comprises conveying at least a portion of the unbound metal powder through perforations of the plurality of perforations.

4 . The method of claim 2 , wherein an upper surface of the tray is corrugated.

5 . The method of claim 1 , wherein generating the liquid currents within the liquid in the container using the at least one source of agitation comprises heating the liquid.

6 . The method of claim 1 , wherein generating the liquid currents within the liquid in the container using the at least one source of agitation comprises vibrating the container.

7 . The method of claim 1 , wherein generating the liquid currents within the liquid in the container using the at least one source of agitation comprises moving the one or more additively fabricated parts in a cyclical motion within the liquid.

8 . The method of claim 1 , wherein:
arranging the one or more additively fabricated parts within the container comprises arranging the one or more additively fabricated parts within the container and above an upper surface of the liquid in the container, and generating the liquid currents within the liquid in the container using the at least one source of agitation comprises directing liquid from outside of the container onto the one or more additively fabricated parts such that the directed liquid is deposited into the container while conveying unbound metal powder into the container.

9 . A depowdering system for removing powder from additively fabricated parts comprising bound metal powder and having unbound metal powder on their surface, the depowdering system comprising:
a container configured to hold liquid and having at least one inlet and at least one outlet; a holder configured to hold one or more additively fabricated parts within the container; a source of agitation configured to produce currents within the liquid held by the container and to thereby convey at least some of the unbound metal powder away from the one or more additively fabricated parts; a liquid pump coupled to the at least one inlet of the container and configured to move liquid into the container through the at least one inlet; and a filtration device coupled to the at least one outlet and configured to filter particles of metal power from liquid passing through the at least one filtration device.

10 . The depowdering system of claim 9 , wherein the holder comprises a tray.

11 . The depowdering system of claim 10 , wherein the tray includes a corrugated upper surface.

12 . The depowdering system of claim 10 , wherein the tray has a plurality of perforations.

13 . The depowdering system of claim 9 , wherein the holder is configured to be operated by the depowdering system to tilt relative to the container.

14 . The depowdering system of claim 9 , wherein the source of agitation includes one or more mechanical vibrators and/or ultrasonic transducers coupled to the container.

15 . The depowdering system of claim 9 , wherein the source of agitation includes one or more mechanical stirrers arranged within the container.

16 . The depowdering system of claim 9 , wherein the source of agitation includes one or more liquid jets and/or gas jets.

17 . The depowdering system of claim 9 , wherein the holder is coupled to one or more actuators configured to move the holder, and wherein the source of agitation includes the one or more actuators.

18 . The depowdering system of claim 9 , wherein the container has a tapered bottom.

19 . The depowdering system of claim 18 , wherein the at least one outlet includes an outlet within the tapered bottom of the container.

20 . The depowdering system of claim 18 , wherein the container is conical.

21 . The depowdering system of claim 9 , wherein the container is cylindrical and the at least one inlet includes an inlet directed tangentially to a side of the container.

22 . The depowdering system of claim 9 , wherein the filtration device comprises a sedimentation container, a carbon filter, and/or a cyclonic separator.

23 . The depowdering system of claim 9 , wherein the at least one outlet is coupled to the at least one inlet such that the depowdering system may be operated to continuously circulate the liquid through the at least one outlet, through the filtration device and through the at least one inlet.

Assignees

• Desktop Metal Inc

Inventors

• Go Jamison
• Sachs Daniel
• Nick Robert J
• Myerberg Jonah Samuel
• Goldblatt Michael

Classifications

• Y02P10/25

  Process efficiency · CPC title

• B22F10/14

  by jetting of binder onto a bed of metal powder · CPC title

• B22F10/68

  Cleaning or washing · CPC title

• B22F2999/00

  Aspects linked to processes or compositions used in powder metallurgy · CPC title

• B22F10/73

  of powder · CPC title