Superelastic alloy

Patent metadata

Field	Value
Publication number	US-10501826-B2
Application number	US-201515518112-A
Country	US
Kind code	B2
Filing date	Oct 14, 2015
Priority date	Oct 23, 2014
Publication date	Dec 10, 2019
Grant date	Dec 10, 2019

Abstract

The present invention provides a superelastic alloy containing Au in an amount of 8.0% by mass or more and 20.0% by mass or less and at least one of Cr and Mo as essential additive elements, Ta as an optional additive element, and Ti and inevitable impurities as a balance, wherein the Cr equivalent calculated on the basis of the following formula for the relationship of the Cr content, the Mo content and the Ta content is within the range of more than 0.5 and less than 8.0. The alloy is a Ni-free superelastic alloy, and has favorable X-ray-imaging property. Accordingly, the alloy can be suitably used in medical fields.

Cr equivalent=[Cr content (% by mass)]+([Mo content (% by mass)]/1.7)+([Ta content (% by mass)]/15)  [Formula 1]

First claim

The invention claimed is:

1. A superelastic alloy containing Au in an amount of 8.0% by mass or more and 20.0% by mass or less, Ta in an amount of 9.0% by mass or more and 20.0% by mass or less, either Cr or Mo as additive elements, and Ti and inevitable impurities as a balance, wherein
a Cr equivalent calculated on a basis of Formula 1 for a relationship of a Cr content, a Mo content and a Ta content is within the range of more than 0.5 and less than 8.0;
Cr equivalent=[Cr content (% by mass)]+([Mo content (% by mass)]/1.7)+([Ta content (% by mass)]/15)  [Formula 1]

and wherein the superelastic alloy contains Ti 3 Au and Ta 3 Au intermetallic compounds and has a superelastic shape recovery ratio of 50% or more calculated on a basis of Formula 2 when subjected to a tension test and unloaded residual strain:
superelastic shape recovery ratio (%)=2% deformation plastic strain (%)−residual strain (%)/2% deformation plastic strain×100  [Formula 2]

wherein the plastic strain is a value obtained by subtracting an elastic deformation strain from a total deformation strain.

2. The superelastic alloy according to claim 1 , wherein the additive elements include Au, Cr, and Ta, and the Cr content is 4.0% by mass or more.

3. The superelastic alloy according to claim 1 , wherein the additive elements include Au, Mo, and Ta, and the Mo content is 6.8% by mass or more.

4. The superelastic alloy according to claim 1 , wherein a ratio of a sum of the Ta content and the Ti content to the Au content ([Au content (% by mass)]/[Ta content (% by mass)]+[Ti content (% by mass)]) is less than 0.29.

5. The superelastic alloy according to claim 1 , wherein the sum of the Au content and the Ta content ([Au content (% by mass)]+[Ta content (% by mass)] is 8.0% by mass or more and 40.0% by mass or less.

6. The superelastic alloy according to claim 2 , wherein a ratio of a sum of the Ta content and the Ti content to the Au content ([Au content (% by mass)]/[Ta content (% by mass)]+[Ti content (% by mass)]) is less than 0.29.

7. The superelastic alloy according to claim 3 , wherein a ratio of a sum of the Ta content and the Ti content to the Au content ([Au content (% by mass)]/[Ta content (% by mass)]+[Ti content (% by mass)]) is less than 0.29.

8. The superelastic alloy according to claim 2 , wherein the sum of the Au content and the Ta content ([Au content (% by mass)]+[Ta content (% by mass)] is 8.0% by mass or more and 40.0% by mass or less.

9. The superelastic alloy according to claim 3 , wherein the sum of the Au content and the Ta content ([Au content (% by mass)]+[Ta content (% by mass)] is 8.0% by mass or more and 40.0% by mass or less.

10. The superelastic alloy according to claim 4 , wherein the sum of the Au content and the Ta content ([Au content (% by mass)]+[Ta content (% by mass)] is 8.0% by mass or more and 40.0% by mass or less.

Assignees

• Tanaka Precious Metal Ind
• Tokyo Inst Tech

Inventors

• Hosoda Hideki
• Inamura Tomonari
• Tahara Masaki
• Shinohara Yuri
• Fuchiwaki Kota
• Goto Kenji

Classifications

• C22F1/18

  High-melting or refractory metals or alloys based thereon · CPC title

• A61L31/00

  Materials for other surgical articles {, e.g. stents, stent-grafts, shunts, surgical drapes, guide wires, materials for adhesion prevention, occluding devices, surgical gloves, tissue fixation devices (shape or structure of stent-grafts A61F2/07, of stents A61F2/82, of surgical gloves A61B42/00, of surgical drapes A61B46/00, of occluding devices A61B17/12022)} · CPC title

• C22F1/00

  Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working (apparatus for mechanical working of metal B21, B23, B24) · CPC title

• C22F1/183

  of titanium or alloys based thereon · CPC title

• C22C14/00 Primary

  Alloys based on titanium · CPC title