Ti, Al and Nb alloys

• US 7,682,473 B2
• Filed: 10/18/2006
• Issued: 03/23/2010
• Est. Priority Date: 10/19/2005
• Status: Active Grant

• Current Assignee: The Board of Trustees of Michigan State University (Michigan State University)
• Original Assignee: The Board of Trustees of Michigan State University (Michigan State University)
• Inventors: Boehlert, Carl J.
• Primary Examiner(s): King; Roy
• Assistant Examiner(s): KIECHLE, CAITLIN ANNE
• Application Number:
  US11/583,666
• Publication Number:
  US 20070084530A1
• Time in Patent Office: 1,252 Days
• Field of Search: 148/417, 148/418, 148/421, 148/425, 148/426, 148/670, 623/11.11, 420/417, 420/418, 420/425, 420/426
• US Class Current: 148/670
• CPC Class Codes: A61L 27/06 Titanium or titanium alloys
• CPC Class Codes: A61L 27/50 Materials characterised by their function or physical properties , e.g. injectable or lubricating compositions, shape-memory materials, surface modified materials
• CPC Class Codes: C22C 14/00 Alloys based on titanium
• CPC Class Codes: C22F 1/183 of titanium or alloys based thereon

Abstract

A method for forming a finished implant prosthesis which comprises:

• • (a) providing an unforged alloy consisting essentially of Ti(x %)Al(y %)Nb wherein x is between about 45 to 54% by atoms, y is between about 15 to 25% by atoms and the balance is niobium;
  • (b) forging the alloy at an elevated temperature below a melting point of the alloy in a shape which is an implant preform; and
  • (c) machining the implant preform to provide a machined implant; and
  • (d) finishing the exposed surfaces of the implant so as to provide the exposed surfaces with a finish which provides biocompatibility, to thereby form the implant prosthesis.

Claims

1. A method for forming a finished implant prosthesis which comprises:

(a) providing an unforged alloy consisting essentially of Ti(x %)Al(y %)Nb wherein x is between about 45 to 54% by atoms, y is between about 15 to 25% by atoms and the balance is niobium;

(b) forging the alloy at an elevated temperature below a melting point of the alloy in a shape which is an implant preform; and

(c) machining the implant preform to provide a machined implant; and

(d) finishing the exposed surfaces of the implant so as to provide the exposed surfaces with a finish which provides biocompatibility, to thereby form the implant prosthesis.

2. The method of claim 1 wherein the alloy is Ti-15Al-33Nb.

4. The method of any one of claims 1, 2 or 3 wherein the implant prosthesis is biocompatible in mouse testing of implanted micron sized particles of the alloy.

8. The method of claim 1 wherein the forging of the alloy is at a temperature greater than 899°

C.

9. The method of claim 1 wherein the forged alloy exhibits a fatigue strength of at least 800 MPa.

10. The method of claim 9 wherein the forged alloy exhibits a fatigue strength of at least 800-950 MPa.

11. The method of claim 10 wherein the forged alloy exhibits a fatigue strength between 850-875 MPa.

3. A method for forming a finished implant prosthesis which comprises:

(a) providing an unforged alloy of Ti-21Al-29Nb;

(b) forging the alloy at an elevated temperature below a melting point of the alloy in a shape which is an implant preform; and

(c) machining the implant preform to provide a machined implant; and

(d) finishing the exposed surfaces of the implant so as to provide the exposed surfaces with a finish which provides biocompatibility, to thereby form the implant prosthesis.

5. In a method for treating a patient by implanting an implant prosthesis with modification of a bone surface so as to accept the prosthesis, the improvement which comprises:

(a) implanting the implant prosthesis wherein the implant prosthesis comprises a forged and machined alloy consisting essentially of Ti(x %)Al(y %)Nb, wherein x is between about 45 to 54% by atoms and wherein y is between about 15 to 25% by atoms and the balance is Nb, wherein the implant is able to withstand at least 10⁵ fatigue cycles at a stress of 400 MPa and has a surface finish which is biocompatible.

6. The method of claim 5 wherein the alloy is Ti-15Al-33Nb.

7. In a method for treating a patient by implanting an implant prosthesis with modification of a bone surface so as to accent the prosthesis, the improvement which comprises:

(a) implanting the implant prosthesis wherein the implant prosthesis comprises a forged and machined alloy of Ti-21Al-29Nb, wherein the implant is able to withstand at least 10⁵ fatigue cycles at a stress of 400 MPa and has a surface finish which is biocompatible.

12. A method for forming a finished implant prosthesis which comprises:

(a) providing an unforged alloy consisting essentially of Ti(x %)Al(y %)Nb wherein x is between about 50 to 52% by atoms, y is between about 15 to 21% by atoms and the balance is niobium;

(b) forging the alloy at an elevated temperature below a melting point of the alloy in a shape which is an implant preform; and

(c) machining the implant preform to provide a machined implant; and

(d) finishing the exposed surfaces of the implant so as to provide the exposed surfaces with a finish which provides biocompatibility, to thereby form the implant prosthesis.

13. The method of claim 12 wherein the forging of the alloy is at a temperature greater than 899°

C.

14. The method of claim 12 wherein the forged alloy exhibits a fatigue strength of at least 800 MPa.

15. The method of claim 14 wherein the forged alloy exhibits a fatigue strength between 800-900 MPa.

16. The method of claim 15 wherein the forged alloy exhibits a fatigue strength between 850-875 Mpa.