Nickel-titanium alloy including a rare earth element

Patent metadata

Field	Value
Publication number	US-9873933-B2
Application number	US-201514703200-A
Country	US
Kind code	B2
Filing date	May 4, 2015
Priority date	Sep 6, 2006
Publication date	Jan 23, 2018
Grant date	Jan 23, 2018

Abstract

Disclosed herein is a nickel-titanium alloy comprising nickel, titanium, and at least one rare earth element. The nickel-titanium alloy comprises from about 34 at. % to about 60 at. % nickel, from about 34 at. % to about 60 at. % titanium, and from about 0.1 at. % to about 15 at. % at least one rare earth element. The nickel-titanium alloy may further include one or more additional alloying elements. In addition to radiopacity, the nickel-titanium alloy preferably exhibits superelastic or shape memory behavior. Medical devices comprising the nickel-titanium alloy and a method of making them are also disclosed.

First claim

The invention claimed is:

1. A method of making a medical device comprising at least one component, the method comprising:
forming a melt comprising from about 34 at. % to about 60 at. % nickel, from about 34 at. % to about 60 at. % titanium, and from about 2.5 at. % to about 15 at. % at least one rare earth element, wherein the at least one rare earth element is selected from the group consisting of La, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Ac, Th, Pa and U;
cooling the melt to form a solid; and
forming the solid into a component comprising a nickel-titanium alloy having an austenite finish temperature at or below 37° C., the nickel-titanium alloy being superelastic at body temperature.

2. The method of claim 1 , wherein forming the solid into the component comprises:
hot working the solid into a first shape; and
cold working the first shape into the component.

3. The method of claim 2 , wherein the hot working is carried out at a temperature in the range of from about 700° C. to about 950° C.

4. The method of claim 2 , wherein the hot working comprises extruding, hot rolling or forging.

5. The method of claim 2 , wherein the cold working comprises cold drawing or cold rolling.

6. The method of claim 2 , wherein the cold working comprises interpass annealing treatments at temperatures in the range of from about 600° C. to about 800° C.

7. The method of claim 1 , further comprising solution heat treating the solid at a temperature of at least about 1,000° C.

8. The method of claim 1 , wherein forming the solid into the component comprises annealing the component while constrained in a final shape at a temperature in the range of from about 350° C. to about 550° C.

9. The method of claim 1 , further comprising machining the component.

10. The method of claim 1 , wherein forming the melt comprises employing one or more of: vacuum induction melting, vacuum consumable arc melting, and electron beam melting.

11. The method of claim 1 , wherein the melt includes the rare earth element in an amount from about 2.5 at. % to about 7.5 at. %.

12. The method of claim 1 , wherein the melt further comprises one or more additional alloying elements in an amount from about 0.1 at. % to about 14.9 at. %.

13. The method of claim 12 , wherein the one or more additional alloying elements are selected from the group consisting of: Al, Cr, Mn, Fe, Co, Cu, Zn, Ga, Ge, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, In, Sn, Sb, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Tl, Pb, Bi, Po, V and Mischmetal.

14. The method of claim 1 , wherein an insertable or implantable medical device comprises the component.

Assignees

• Cook Medical Technologies Llc

Inventors

• Tofail Syed Ansar Md
• Carlson James M
• Carr Shane
• Devereux Paul
• Haverty Donncha
• Lavelle Shay J
• Mcgloughlin Tim

Classifications

• Y10T29/49988

  Metal casting · CPC title

• B21C23/00

  Extruding metal; Impact extrusion · CPC title

• B21J5/00

  Methods for forging, hammering, or pressing (for working sheet-metal or metal tubes, rods, or profiles B21D; for working wire B21F); Special equipment or accessories therefor · CPC title

• C22C14/00

  Alloys based on titanium · CPC title

• C22C19/03

  based on nickel · CPC title