LOW COST PROCESSING TO PRODUCE SPHERICAL TITANIUM AND TITANIUM ALLOY POWDER

• US 20120272788A1
• Filed: 04/13/2012
• Published: 11/01/2012
• Est. Priority Date: 04/27/2011
• Status: Active Grant

• Current Assignee: Ats Mer, LLC
• Original Assignee: Materials and Electrochemical Research Corporation
• Inventors: Withers, James C., Loutfy, Raouf O.
• Granted Patent: US 8,911,529 B2
• Time in Patent Office: Days
• US Class Current: 75/335
• CPC Class Codes: B22F 1/065 Spherical particles
• CPC Class Codes: B22F 2009/0848 Melting process before atomisation
• CPC Class Codes: B22F 2201/01 Reducing atmosphere
• CPC Class Codes: B22F 2202/01 Use of vibrations
• 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 9/082 atomising using a fluid using centrifugal force B22F9/10
• CPC Class Codes: B22F 9/24 starting from liquid metal compounds, e.g. solutions
• CPC Class Codes: C22C 1/0458 Alloys based on titanium, zirconium or hafnium
• CPC Class Codes: C22C 14/00 Alloys based on titanium

Abstract

Low cost spherical titanium and titanium powder alloy powder is produced by impinging a stream of an inert gas, such as argon, on the surface of a molten pool of titanium or sponge and alloying elements.

Claims

1. ) A process for producing spherical titanium alloy powder comprising forming a molten pool or stream of titanium sponge with alloying elements added thereto, impinging a stream of an inert gas across the surface of the molten pool or through the stream whereby to dislodge droplet particles of titanium alloy from the molten pool or stream, and cooling and solidifying the dislodged droplet particles to form spherical titanium alloy powder.

2. ) The process of claim 1 wherein the molten pool or stream is formed in a plasma heating system.

3. ) The process of claim 1, wherein the molten pool or stream is formed by co-melting a feed of titanium sponge and alloying elements.

4. ) The process of claim 3, wherein the alloying elements comprise aluminum and vanadium.

5. ) The process of claim 4, wherein the alloying elements are pre-alloyed.

6. ) The process of claim 1, wherein the inert gas comprises argon.

7. ) The process of claim 1, wherein the molten pool is vibrated.

19. ) The process of claim 2, wherein the alloy is Ti-6Al-4V.

22. ) The process of claim 2, wherein the alloy is Ti-8Al-1Mo-1V.

25. ) The process of claim 1, wherein the melt is formed from an ingot.

26. ) The process of claim 1, performed on a continuous basis.

8. ) A process for producing titanium alloy powders comprising forming a molten pool or stream of electrolytically-produced titanium powder containing residual salt, evaporating the salt, conveying the salt depleted titanium to a plasma heating system together with alloying elements to form a molten pool or stream of titanium alloy, impinging a stream of inert gas across the surface of the molten pool or through the stream of titanium alloy to dislodge droplet particles of titanium from the melt, and cooling and solidifying the dislodged droplet particles to form spherical titanium alloy powder.

9. ) The process of claim 8, wherein the residual salt is evaporated by heating in an inert atmosphere under reduced pressure.

10. ) The process of claim 8, wherein the inert gas comprises argon.

11. ) The process of claim 8, wherein the molten pool is vibrated.

12. ) A process for producing spherical titanium alloy particles, which comprises co-melting titanium sponge containing residual magnesium chloride and magnesium metal with alloying elements in a plasma melter, evaporating the magnesium chloride and magnesium to form a pool or stream of titanium alloy melt, and impinging a stream of an inert gas across the surface of the titanium alloy melt or through the stream to dislodge droplet particles of titanium alloy, and cooling the dislodged droplet particles to produce spherical alloy titanium powder particles.

13. ) The process of claim 12, wherein the inert gas comprises argon.

14. ) The process of claim 12, wherein the droplet particles are formed by passing the alloy melt through an orifice surrounded by a flow of inert gas.

15. ) The process of claim 14, including the step of collecting the droplet particles in a liquid pool of argon.

16. ) The process of claim 12, wherein the pool is vibrated.

20. ) The process of claim 12, wherein the alloy is Ti-6Al-4V.

23. ) The process of claim 12, wherein the alloy is Ti-8Al-1Mo-1V.

27. ) The process of claim 12, performed on a continuous basis.

17. ) In a process for producing spherical titanium alloy particles, wherein an electrolytically produced titanium powder in a stream of the salt electrolyte at or above an operating temperature of 500°

C. is conveyed into a induction heated evaporator operated at or above 900°

C. and under reduced pressure to evaporate the salt electrolyte that is returned to the electrolytic cell, and the resulting titanium powder is conveyed to a plasma melter along with alloying elements to produce a pool or stream of melted alloy, the improvement wherein an inert gas is impinged on the molten pool or through the stream to dislodge droplet particles, and cooling and solidifying the dislodged droplet particles to produce spherical titanium alloy powder.

18. ) The process of claim 17, wherein the pool is vibrated.

21. ) The process of claim 17, wherein the alloy is Ti-6Al-4V.

24. ) The process of claim 17, wherein the alloy is Ti-8Al-1Mo-1V

28. ) The process of claim 17, performed on a continuous basis.