Porous nickel-titanium alloy article

• US 5,986,169 A
• Filed: 12/31/1997
• Issued: 11/16/1999
• Est. Priority Date: 12/31/1997
• Status: Expired due to Term

• Current Assignee: Nitinol Devices and Components, Tomsk Medical Engineering Centre of Shape Memory Implant
• Original Assignee: Biorthex Inc.
• Inventors: Gjunter, Victor
• Primary Examiner(s): Milano, Michael J.
• Application Number:
  US09/001,496
• Time in Patent Office: 685 Days
• Field of Search: 623/16, 623/11, 623/66, 623/18
• US Class Current: 424/422
• CPC Class Codes: A61L 27/06 Titanium or titanium alloys
• CPC Class Codes: A61L 27/56 Porous materials, e.g. foams or sponges
• CPC Class Codes: B22F 2999/00 Aspects linked to processes or compositions used in powder metallurgy
• CPC Class Codes: B22F 3/1143 involving an oxidation, reduction or reaction step
• CPC Class Codes: B22F 3/23 involving a self-propagating high-temperature synthesis or reaction sintering step making cermets by reaction sintering C22C1/051
• CPC Class Codes: C22C 1/047 comprising intermetallic compounds C22C1/0441 takes precedence
• CPC Class Codes: Y10S 623/924 Material characteristic

Abstract

A porous article of a nickel-titanium alloy, said article having a porosity of 8 to 90% and said porosity being defined by a network of interconnected passageways extending throughout said member, said network exhibiting a permeability of fluid material effective to permit complete migration of the fluid material throughout said network, said permeability being isotropic, and said member being elastically deformable; the porous article is useful as a biomedical implant and in other non-medical applications including the working element of cryogenic surgical instruments.

Claims

1. A porous article having a porous sintered powder body based on a nickel-titanium alloy, said article having a porosity of 8 to 90% and said porosity being defined by a network of interconnected passageways extending throughout said sintered powdered body, said network exhibiting a permeability for fluid material effective to permit complete migration of the fluid material throughout said network, said permeability arising from capilliarity in said network and said network having a distribution of pores as follows:

space="preserve" listing-type="tabular">______________________________________ Pore Size in Microns Quantity ______________________________________ 10.sup.-2 -10.sup.-1 1-15% 10.sup.1 -10 5-10% 10-100 10-20% 100-400 20-50% 400-1000 10-50% above 1000 remainder to 100%, ______________________________________

said article being elastically deformable.

2. A porous article according to claim 1, wherein said alloy is a biocompatible alloy.

3. A porous article according to claim 2, wherein said network is permeable to biological tissue in a biological fluid, and said network comprises pores of a size to permit growth of biological tissue therein.

4. A porous article according to claim 3, having a porosity of at least 40%.

5. A porous article according to claim 4, having a porosity of not more than 80%.

6. A porous article according to claim 5, having a coefficient of permeability of 2×

10^--- to 2×

10^-5.

7. A porous article according to claim 1, wherein said alloy comprises 2 to 98%, by weight, titanium and 98 to 2%, by weight, nickel, to a total of 100%.

8. A porous article according to claim 6, wherein said alloy comprises 40 to 60%, by weight, titanium and 60 to 40%, by weight, nickel to a total of 100%.

9. A porous article according to claim 1, in the form of a biomedical implant.

10. A porous article according to claim 8, in the form of a biomedical implant.

11. A porous article according to claim 1, wherein said permeability is isotropic.

12. A porous article according to claim 1, wherein said alloy comprises 40 to 60%, by weight, titanium and 60 to 40%, by weight, nickel, to a total of 100%.