Method for fabricating biocompatible porous titanium

Patent metadata

Field	Value
Publication number	US-9481036-B2
Application number	US-201214362751-A
Country	US
Kind code	B2
Filing date	Dec 10, 2012
Priority date	Dec 9, 2011
Publication date	Nov 1, 2016
Grant date	Nov 1, 2016

Abstract

A method for fabricating porous metal constructs (such as porous Ti constructs) which may be used as implants in bone repair is disclosed. The method employs a new saltbath sintering process coupled with conventional powder metallurgy technology which is capable of fabricating porous metal constructs with controlled porosity and pore size having a lower production cost than conventional powder metallurgy methods.

First claim

What is claimed is:

1. A method for fabricating biocompatible porous metals, the method comprising:
mixing a metal powder and a salt to form a mixture;
compacting the mixture in a die under pressure to form a construct comprising a predetermined shape; and
sintering the construct in a molten sodium chloride bath to produce a sintered construct.

2. The method of claim 1 and further comprising soaking the sintered construct in a water bath to remove at least a portion of the salt to reveal a plurality of pores within the sintered construct.

3. The method of claim 1 , wherein mixing the metal power and the salt comprises a dry-mixing step and a wet-mixing step.

4. The method of claim 3 , wherein the dry-mixing step comprises mixing the metal powder and the salt in a tumbler for a predetermined amount of time to form a dry mix.

5. The method of claim 4 , wherein the wet-mixing step comprises mixing the dry mix with a volume of acetone to form the mixture.

6. The method of claim 1 , wherein the metal comprises at least one of titanium, niobium, zirconium, tantalum, tungsten, and stainless steel.

7. The method of claim 1 , wherein the salt comprises at least one of sodium chloride and potassium chloride.

8. The method of claim 1 , wherein the molten sodium chloride bath comprises liquid sodium chloride at a temperature of at least 1200° C. in an alumina crucible.

9. The method of claim 1 , wherein the construct is sintered in the molten sodium chloride bath for between about 1 and about 3 hours.

10. A method for fabricating biocompatible porous titanium, the method comprising:
mixing a titanium powder and a salt to form a mixture;
compacting the mixture in a die under pressure to form a construct comprising a predetermined shape;
sintering the construct in a molten sodium chloride bath to produce a sintered construct; and
removing at least a portion of the salt from the sintered construct to reveal a plurality of pores defined through a portion of the sintered construct.

11. The method of claim 10 , wherein removing at least a portion of the salt from the sintered construct comprises soaking the sintered construct in a water bath.

12. The method of claim 10 , wherein removing at least a portion of the salt from the sintered construct comprises heating the sintered construct to a temperature greater than a melting temperature of the salt.

13. The method of claim 10 , wherein the salt comprises one of sodium chloride and potassium chloride.

14. The method of claim 10 , wherein mixing the titanium power and the salt comprises a dry-mixing step and a wet-mixing step.

15. The method of claim 14 , wherein the dry-mixing step comprises mixing the metal powder and the salt in a tumbler for a predetermined amount of time to form a dry mix.

16. The method of claim 15 , wherein wet-mixing step comprises mixing the dry mix with a volume of acetone to form the mixture.

17. The method of claim 10 , wherein the molten sodium chloride bath comprises liquid sodium chloride at a temperature of at least 1200° C. in an alumina crucible.

18. The method of claim 17 , wherein sintering the construct comprises raising the temperature of the molten sodium chloride bath at a rate of between 0.1 to 100° C. per minute.

19. The method of claim 18 , wherein the rate is approximately 10° C. per minute.

20. The method of claim 10 , wherein the construct is sintered in the molten sodium chloride bath for between about 1 and about 3 hours.

Assignees

• Univ Missouri

Inventors

• Bal B Sonny
• Huang Tieshu
• Rahaman Mohamed N

Classifications

• B22F2998/00

  Supplementary information concerning processes or compositions relating to powder metallurgy · CPC title

• B22F3/1134 Primary

  Inorganic fillers (carbonaceous or paper filler B22F3/1121) · CPC title

• C22C14/00

  Alloys based on titanium · CPC title

• B22F2009/043

  by ball milling · CPC title

• B22F3/1121 Primary

  by using decomposable, meltable or sublimatable fillers · CPC title