Depowdering of additively manufactured objects with small and/or complex internal geometries

Patent metadata

Field	Value
Publication number	US-12208573-B2
Application number	US-202017107726-A
Country	US
Kind code	B2
Filing date	Nov 30, 2020
Priority date	Nov 30, 2020
Publication date	Jan 28, 2025
Grant date	Jan 28, 2025

Abstract

A method of depowdering objects (e.g., heat exchangers) having small and/or complex internal geometries and manufactured using an additive manufacturing technique performed with a powder material. The method includes applying a pressurized fluid to the objects via a pressurized fluid applicator operatively coupled to the object, thereby removing a portion of unbound powder material on or in the object. The method further includes applying vortex vibration to the object via a vortex vibration source operatively coupled to the object, thereby loosening a portion of the unbound powder material remaining on or in the object, and applying the pressurized fluid to the object via the pressurized fluid application, thereby removing a portion of the loosened, unbound powder material from the object. The latter two applying steps are repeated until a specified amount of the unbound powder material has been removed from the object.

First claim

The invention claimed is:

1. A method of depowdering an object manufactured using an additive manufacturing technique performed with a powder material, the method comprising:
(a) applying a pressurized fluid to the object via a pressurized fluid applicator operatively coupled to the object, thereby removing a portion of unbound powder material on or in the object;
(b) applying vortex vibration to the object via a vortex vibration source operatively coupled to the object, thereby loosening a portion of the unbound powder material remaining on or in the object;
(c) applying the pressurized fluid to the object via the pressurized fluid application, thereby removing a portion of the loosened, unbound powder material from the object;
(d) repeating steps (b) and (c) until a specified amount of the unbound powder material has been removed from the object; and
(e) determining whether the specified amount of the unbound power material has been removed from the object by comparing a weight of the object before step (a) and the weight of the object after step (b),
wherein the object comprises one or more internal passages, wherein step (b) loosens a portion of the unbound powder material remaining in the one or more internal passages, wherein the vortex vibration source is a vortex mixer having a shelf configured to receive and retain the object, and wherein step (b) comprises positioning the object on the shelf of the vortex mixer.

2. The method of claim 1 , wherein the specified amount comprises substantially all or all of the unbound powder material.

3. The method of claim 1 , wherein each of the one or more internal passages has an internal diameter equal to between approximately 1 mm and approximately 20 mm.

4. The method of claim 1 , wherein steps (b) and (c) are repeated a number of times based on one or more parameters of the object.

5. The method of claim 4 , wherein the one or more parameters comprise one or more of a shape, a size, a surface roughness, an internal geometry, and layers of the object.

6. The method of claim 1 , wherein step (b) comprises applying the vortex vibration at a vortex speed for a period of time, and wherein the vortex speed and the period of time depend on one or more parameters of the object.

7. The method of claim 1 , wherein step (b) is performed without applying any fluid to the object.

8. The method of claim 1 , wherein the pressurized fluid applicator comprises:
a single pressurized fluid nozzle configured to directly apply the pressurized fluid to the object;
a pressurized fluid source; and
a pressurized fluid conduit connected to the single pressurized fluid nozzle and to the pressurized fluid source, the pressurized fluid conduit configured to provide the pressurized fluid from the pressurized fluid source to the single pressurized fluid nozzle.

9. The method of claim 8 , further comprising a robotic arm coupled to the single pressurized fluid nozzle, the robotic arm configured to freely articulate the single pressurized fluid nozzle relative to the object.

10. A method of depowdering an object manufactured using additive manufacturing performed with a powder material, the method comprising:
(a) removing a portion of unbound powder material from the object by applying a pressurized fluid to the object via the pressurized fluid applicator operatively coupled to the object;
(b) loosening a portion of the unbound powder material remaining on or in the object by applying vortex vibration to the object via a vortex vibration source operatively coupled to the object;
(c) removing a portion of the loosened, unbound powder material by applying the pressurized fluid to the object via the pressurized fluid applicator; and
(d) repeating steps (b) and (c) until a specified amount of the unbound powder material has been removed from the object,
wherein the object comprises one or more internal passages each having an internal diameter equal to between approximately 1 mm and 20 mm, wherein step (b) loosens a portion of the unbound powder material remaining in the one or more internal passages, and wherein the pressurized fluid applicator consists of a single pressurized fluid nozzle configured to directly apply the pressurized fluid to the object.

11. The method of claim 10 , wherein the specified amount comprises substantially all or all of the unbound powder material.

12. The method of claim 10 , wherein steps (b) and (c) are repeated a number of times based on one or more parameters of the object.

13. The method of claim 12 , wherein the one or more parameters comprise one or more of a shape, a size, a surface roughness, an internal geometry, and layers of the object.

14. The method of claim 10 , wherein step (b) comprises applying the vortex vibration at a vortex speed for a period of time, and wherein the vortex speed and the period of time depend on one or more parameters of the object.

15. The method of claim 10 , wherein step (b) is performed without applying any fluid to the object.

16. The method of claim 10 , further comprising determining whether the specified amount of the unbound powder material has been removed from the object by comparing a weight of the object before step (a) and after step (b).

17. The method of claim 10 , further comprising determining that the specified amount of the unbound powder material has been removed when the object reaches a pre-determined weight corresponding to removal of the specified amount of the unbound powder material.

18. A method of additively manufacturing a heat exchanger, the method comprising:
(a) forming the heat exchanger using an additive manufacturing technique performed with a powder material;
(b) removing a portion of unbound powder material from the heat exchanger by applying a pressurized fluid to the heat exchanger via a pressurized fluid applicator operatively coupled to the heat exchanger;
(c) loosening a portion of the unbound powder material remaining on or in the heat exchanger by applying vortex vibration to the heat exchanger via a vortex vibration source operatively coupled to the heat exchanger;
(d) removing a portion of the loosened, unbound powder material by applying the pressurized fluid to the heat exchanger via the pressurized fluid applicator; and
(e) repeating steps (c) and (d) until a specified amount of the powder material has been removed from the heat exchanger,
wherein the heat exchanger comprises one or more internal passages, and wherein step (c) loosens a portion of the unbound powder material remaining in the one or more internal passages.

19. The method of claim 18 , further comprising curing the heat exchanger when the specified amount of the powder material has been removed.

20. The method of claim 18 , wherein the additive manufacturing technique comprises binder jetting.

21. The method of claim 20 , wherein (a) comprises:
depositing a first layer of the powder material on a building platform;
applying a binding agent to the first layer of the powder material;
depositing a second layer of the powder material on the first layer;
applying the binding agent to the second layer of the powder material; and
repeating the depositing and applying steps until the heat exchanger has been formed.

Assignees

• Uchicago Argonne Llc

Inventors

• Yu Wenhua
• Singh Dileep
• France David M
• Du Wenchao

Classifications

• B33Y80/00

  Products made by additive manufacturing · CPC title

• B08B7/02

  by distortion, beating, or vibration of the surface to be cleaned {(B08B7/0007 takes precedence)} · CPC title

• B08B5/02

  Cleaning by the force of jets, e.g. blowing-out cavities {(airguns or nozzles per se B05B1/005)} · CPC title

• B29L2031/18

  Heat-exchangers or parts thereof · CPC title

• B33Y40/20

  Post-treatment, e.g. curing, coating or polishing · CPC title