PROCESS FOR PRODUCING SPHEROIDIZED POWDER FROM FEEDSTOCK MATERIALS

• US 20190381564A1
• Filed: 06/19/2019
• Published: 12/19/2019
• Est. Priority Date: 06/19/2018
• Status: Active Grant

• Current Assignee: 6K Incorporated
• Original Assignee: Amastan Technologies LLC
• Inventors: Barnes, John, Bent, Aaron, Hadidi, Kamal, Redjdal, Makhlouf, Turchetti, Scott, Ullal, Saurabh, Duanmu, Ning, Kozlowski, Michael C.
• Granted Patent: US 10,639,712 B2
• Time in Patent Office: Days
• CPC Class Codes: B22F 1/065 Spherical particles
• CPC Class Codes: B22F 1/142 Thermal or thermo-mechanical treatment
• CPC Class Codes: B22F 2009/001 from scrap particles
• CPC Class Codes: B22F 2202/13 Use of plasma
• CPC Class Codes: B22F 2301/205 Titanium, zirconium or hafnium
• CPC Class Codes: B22F 2304/10 Micron size particles, i.e. above 1 micrometer up to 500 micrometer
• CPC Class Codes: B22F 2998/10 Processes characterised by the sequence of their steps
• CPC Class Codes: B22F 2999/00 Aspects linked to processes or compositions used in powder metallurgy
• CPC Class Codes: B22F 8/00 Manufacture of articles from scrap or waste metal particles
• CPC Class Codes: B22F 9/023 Hydrogen absorption
• CPC Class Codes: B22F 9/04 starting from solid material, e.g. by crushing, grinding or milling C22C1/1084 takes precedence; crushing, grinding or milling, in general, see the relevant subclasses, e.g. B02C
• CPC Class Codes: B22F 9/14 using electric discharge
• CPC Class Codes: B33Y 70/00 Materials specially adapted for additive manufacturing
• CPC Class Codes: C22C 1/0433 Nickel- or cobalt-based alloys
• CPC Class Codes: C22C 1/0458 Alloys based on titanium, zirconium or hafnium
• CPC Class Codes: C22C 14/00 Alloys based on titanium
• CPC Class Codes: C22C 19/03 based on nickel
• CPC Class Codes: C22C 19/07 based on cobalt
• CPC Class Codes: C22C 33/02 by powder metallurgy working metallic powder B22F
• CPC Class Codes: C22C 38/00 Ferrous alloys, e.g. steel alloys cast-iron alloys C22C37/00
• CPC Class Codes: Y02P 10/25 : Process efficiency
• CPC Class Codes: Y02W 30/50 : Reuse, recycling or recovery technologies

Abstract

Disclosed herein are embodiments of methods, devices, and assemblies for processing feedstock materials using microwave plasma processing. Specifically, the feedstock materials disclosed herein pertains to scrap materials, dehydrogenated or non-hydrogenated feed material, and recycled used powder. Microwave plasma processing can be used to spheroidize and remove contaminants. Advantageously, microwave plasma processed feedstock can be used in various applications such as additive manufacturing or powdered metallurgy (PM) applications that require high powder flowability.

Claims

1. A method for manufacturing a spheroidized powder from scrap metal or used metal parts, the method comprising:

providing scrap metal or used metal parts comprising a material selected from the group consisting of metal, metal alloy, titanium, titanium alloy, nickel, nickel alloy, cobalt, cobalt alloy, steel, and steel alloy;

milling the scrap metal or used metal parts to produce metallic particles within a range of particle volumes pre-determined to be suitable for use as feedstock in a microwave plasma process; and

applying the microwave plasma process to the metallic particles within the determined range of particle volumes to form spheroidized powder.

2. The method of claim 1, wherein the determined range of particle volumes is between 15 and 63 microns.

3. The method of claim 1, wherein the scrap metal or used metal parts comprise a work hardened microstructure that is retained in the spheroidized powder after applying the microwave plasma process.

4. The method of claim 1, comprising milling the scrap metal or used metal parts without embrittling the scrap metal or used metal parts.

5. The method of claim 1, wherein the scrap metal or used metal parts comprises Ti 6Al-4V.

6. The method of claim 1, wherein the scrap metal or used metal parts comprise alloy elements including Al, Mg, Ti, and/or Cu and, after applying the microwave plasma process the spheroidized powder still includes the Al, Mg, Ti, and/or Cu.

7. The method of claim 1, wherein the scrap metal or used metal parts comprise sharp turnings, saw swarfs, grinding swarfs, grinding fines, and/or wash line fines.

8. The method of claim 1, wherein the scrap metal or used metal parts are selected for the milling to have a size and/or aspect ratio that will result post-milling in metallic particles within the pre-determined range of particle volumes.

9. A method for manufacturing a spheroidized powder having a desired particle size distribution between about x and about y, wherein x represents a low end of the particle size distribution and y represents a high end of the particle size distribution, the method comprising:

introducing metallic particles obtained by milling or crushing scrap metal or used metal parts into a microwave plasma torch, a majority of said introduced metallic particles having a volume between about 4/3 π

(x/2)³ and about 4/3 π

(y/2)³, and wherein said introduced metallic particles have a collective average or median aspect ratio between 2;

1 and 200;

1; and

melting and spheroidizing the metallic particles within the microwave plasma torch to form spheroidized powder having the desired particle size distribution of about x to about y.

10. The method of claim 9, wherein x=5 microns and y=45 microns and the majority of said introduced metallic particles have a volume between about 65.45 μ

m³ and about 47,712.94 μ

m³.

11. The method of claim 9, wherein the collective average or median aspect ratio is between 5:

1 to 20;

1

12. The method of claim 9, wherein the collective average or median aspect ratio is between 10:

1 to 100;

1.

13. The method of claim 9, wherein the introducing metallic particles into the microwave plasma torch comprises introducing the metallic particles into an exhaust of the microwave plasma torch or into a plume of the microwave plasma torch.

14. A method for manufacturing a spheroidized powder from used powder, the method comprising:

introducing previously used powder particles into a microwave plasma torch, the previously used powder particles comprising satellites, agglomerations, or contaminants; and

melting and spheroidizing the previously used powder particles within the microwave plasma torch to form spheroidized powder particles having the agglomerations, contaminants, and satellites removed.

15. The method of claim 14, wherein the previously used powder particles comprise satellites, agglomerations, and contaminants.

16. The method of claim 14, wherein the previously used powder particles comprise a material selected from the group consisting of metal, metal alloy, titanium, titanium alloy, nickel, nickel alloy, cobalt, cobalt alloy, steel, steel alloy, a ductile metal, a ductile metal alloy, and ceramic.

17. The method of claim 14, wherein carbon and nitrogen is removed from the previously used powder particles during the melting and spheroidizing.

18. The method of claim 14, wherein the previously used powder particles were formed from an additive manufacturing process selected from the group consisting of laser sintering, electron-beam melting, filament fused deposition, directed energy deposition, powder bed fusion, and binder jetting.

19. The method of claim 14, wherein the spheroidized powder particles retain the same rheological properties as the previously used powder particles after the melting and spheroidizing.

20. A method for producing a spheroidized powder from a feed material comprising dehydrogenated or non-hydrogenated titanium or titanium alloy, the method comprising:

introducing a feed material comprising dehydrogenated or non-hydrogenated titanium or titanium alloy particles into a microwave plasma torch; and

melting and spheroidizing the particles within a plasma generated by the microwave plasma torch to form spheroidized powder.

21. The method of claim 20, wherein the feed material comprises titanium or titanium alloy particles processed by a hydrogenation-dehydrogenation (HDH) process.

22. The method of claim 20, wherein the spheroidized powder comprises particles with a median sphericity of at least 0.75.

23. The method claim 20, wherein the spheroidized powder has a particle size distribution of between 5 and 45 microns at a low end of the particle size distribution range and between 15 and 105 microns at a high end of the particle size distribution range.

24. The method of claim 20, wherein one or more processing variables are set to create a martensitic microstructure in the spheroidized particles.

25. The method of claim 20, wherein one or more processing variables are set to create an equiaxed microstructure in the spheroidized particles.

26. The method of claim 20, wherein one or more processing variables are set to create at least two regions in the spheroidized powder, each region having a different microstructure.

27. The method of claim 26, wherein the at least two regions include a core portion and a skin portion, the skin portion having a microstructure that is different from a microstructure of the feed material.

28. The method of claim 20, wherein the feed material has a particle size of no less than 1.0 microns and no more than 300 microns.

29. The method of claim 20, wherein the feed material comprises Ti 6Al-4V.