Shape memory alloy

• US 5,108,523 A
• Filed: 07/24/1990
• Issued: 04/28/1992
• Est. Priority Date: 08/12/1989
• Status: Expired due to Fees

• Current Assignee: Fried Krupp GmbH (Thyssenkrupp AG)
• Original Assignee: Fried Krupp GmbH (Thyssenkrupp AG)
• Inventors: Peterseim, Jurgen, Schlump, Wolfgang
• Primary Examiner(s): Yee, Deborah
• Application Number:
  US07/557,629
• Time in Patent Office: 644 Days
• Field of Search: 148/402, 420/451, 420/417
• US Class Current: 148/402
• CPC Class Codes: C22F 1/006 Resulting in heat recoverable alloys with a memory effect

Abstract

A shape memory alloy for repeated use, containing no noble metals. NiTiZr and NiTiZrCu shape memory alloys having A_s temperature which lies above 100° C. are disclosed. These shape memory alloys have the following composition: 41.5 to 54 atomic % Ni; 24 to 42.5 atomic % Ti and 7.5 to 22 atomic % Zr.

Claims

1. A shape memory alloy having a starting temperature at austenite formation above 100°

C., comprising 41.5 to 54 atomic % Ni, 24 to 42.5 atomic % Ti and 14 to 22 atomic % of at least one element selected from the group consisting of Zr, Hf, and a mixture of Zr and Hf.

2. A shape memory alloy as defined in claim 1, further comprising up to 8.5 atomic % Cu.

3. A shape memory alloy as defined in claim 2, wherein a combined Ni + Cu content is 48.5 to 49 atomic %.

4. A shape memory alloy as defined in claim 2, wherein a combined Ni + Cu content is 47 to 50 atomic %.

5. A shape memory alloy as defined in claim 2, wherein a combined Ni + Cu content is 47 to 50 atomic %.

6. A shape memory alloy as defined in claim 1, wherein the Ti content is 24 to 34 atomic % and said element is present in the amount of 16 to 22 atomic %.

7. A shape memory alloy as defined in claim 1, wherein the Ti content is 24 to 30 atomic % and said element is present in the amount of 20 to 22 atomic %.

8. A shape memory alloy as defined in claim 1 wherein said element is present in the amount of 14 to 19 atomic %.

9. A shape memory alloy as defined in claim 1 wherein said element is present in the amount of 14 to 18 atomic %.