Fe-based shape memory alloy material and method of producing the same

Patent metadata

Field	Value
Publication number	US-10920305-B2
Application number	US-201916252215-A
Country	US
Kind code	B2
Filing date	Jan 18, 2019
Priority date	Sep 6, 2016
Publication date	Feb 16, 2021
Grant date	Feb 16, 2021

Abstract

A Fe-based shape memory alloy material, containing 25 atom % to 42 atom % of Mn, 9 atom % to 13 atom % of Al, 5 atom % to 12 atom % of Ni, and 5.1 atom % to 15 atom % of Cr, with the balance being Fe and unavoidable impurities; a method of producing the same; and a wire material and sheet material composed of the alloy material.

First claim

The invention claimed is:

1. A Fe-based shape memory alloy material, containing 25 atom % to 42 atom % of Mn, 10.5 atom % to 11.5 atom % of Al, 5 atom % to 12 atom % of Ni, and 5.1 atom % to 15 atom % of Cr, with the balance being Fe and unavoidable impurities,
in which a temperature dependency of a transformation-induced stress is 0.30 MPa/° C. or lower.

2. The Fe-based shape memory alloy material as claimed in claim 1 , further containing at least one element selected from the group consisting of 0.1 atom % to 5 atom % of Si, 0.1 atom % to 5 atom % of Ti, 0.1 atom % to 5 atom % of V, 0.1 atom % to 5 atom % of Co, 0.1 atom % to 5 atom % of Cu, 0.1 atom % to 5 atom % of Mo, 0.1 atom % to 5 atom % of W, 0.001 atom % to 1 atom % of B, and 0.001 atom % to 1 atom % of C, at an amount of 15 atom % or less in total.

3. A method of producing the Fe-based shape memory alloy material as claimed in claim 1 , the method including a step of performing a solution treatment at 1,100° C. to 1,300° C.

4. The method of producing the Fe-based shape memory alloy material as claimed in claim 3 , further including a step of performing an aging treatment at 100° C. to 350° C. after the solution treatment step.

5. A wire material formed from the Fe-based shape memory alloy, material as claimed in claim 1 , in which an average grain size of the Fe-based shape memory alloy material is greater than or equal to a radius of the wire material.

6. A sheet material formed from the Fe-based shape memory alloy material as claimed in claim 1 , in which an average grain size of the Fe-based shape memory alloy material is greater than or equal to a thickness of the sheet material.

7. A Fe-based shape memory alloy material, containing 25 atom % to 42 atom % of Mn, 9 atom % to 13 atom % of Al, 5 atom % to 12 atom % of Ni, and 6.0 atom % to 12.0 atom % of Cr, with the balance being Fe and unavoidable impurities,
in which a temperature dependency of a transformation-induced stress is 0.30 MPa/° C. or lower.

8. A Fe-based shape memory alloy material, containing 25 atom % to 42 atom % of Mn, 10.5 atom % to 11.5 atom % of Al, 5 atom % to 12 atom % of Ni, and 6.0 atom % to 12.0 atom % of Cr, with the balance being Fe and unavoidable impurities,
in which a temperature dependency of a transformation-induced stress is 0.30 MPa/° C. or lower.

Assignees

• Univ Tohoku
• Furukawa Techno Mat Co Ltd
• Furukawa Electric Co Ltd

Inventors

• Omori Toshihiro
• Kainuma Ryosuke
• Noguchi Yuki
• Kise Sumio
• Tanaka Toyonobu

Classifications

• C21D8/06

  during manufacturing of rods or wires · CPC title

• C21D6/02

  Hardening by precipitation · CPC title

• C21D8/0273

  Final recrystallisation annealing · CPC title

• C22C38/00

  Ferrous alloys, e.g. steel alloys (cast-iron alloys C22C37/00) · CPC title

• C21D9/525

  for wire, for rods (C21D9/54 takes precedence) · CPC title