Magnetic shape memory alloys and specimens thereof

Patent metadata

Field	Value
Publication number	US-10290405-B2
Application number	US-201214118565-A
Country	US
Kind code	B2
Filing date	May 21, 2012
Priority date	May 20, 2011
Publication date	May 14, 2019
Grant date	May 14, 2019

Abstract

The present technology relates to a Ni—Mn—Ga magnetic shape memory (MSM) alloy including twin boundaries type 2, which are deviated approximately +/−2-4 degrees from (101) or equivalent crystallographic plane by rotation about [−101] or equivalent crystallographic direction. This technology relates also to an actuator, sensor and harvester including MSM element of this technology.

First claim

The invention claimed is:

1. An Magnetic Shape Memory (MSM) specimen for use in an actuator, sensor or energy harvester, said MSM specimen having 5M-crystal structure in which twin boundary motion is facilitated primarily by created twin boundaries type 2 with twinning plane deviating ±2-4 degrees from the (101) or equivalent crystallographic plane by rotation about [−101] or equivalent crystallographic direction, wherein the specimen is a composition comprising at least Ni, Mn and Ga and
wherein the specimen has a MSM effect based on the rearrangement of crystallographic domains in an applied magnetic field and
wherein the twinning stress for the specimen is less than 0.3 MPa.

2. The specimen according to claim 1 , wherein twin boundaries type 2 connects adjacent crystallographic domains by rotation about twin shear direction [−101] or equivalent crystallographic plane, and in result of the rotation the twinning plane of such a boundary is deviated by ±2-4 degrees from the (101) or equivalent crystallographic plane by rotation about [−101] or equivalent crystallographic direction.

3. The specimen according to claim 1 , comprising segmented twin boundaries of type 2.

4. The specimen according to claim 1 , wherein the alloy is 5-layered Ni—Mn—Ga magnetic shape memory alloy.

5. The specimen according to claim 1 further comprising at least one element selected from the group of Cr, Co, Cu, Fe, Ti, Al, In, Zr, Mo, Ta, W, V, Nb, Y and Pd.

6. The specimen according to claim 1 further comprising up to 10 atom-% of at least one element selected from the group of Cr, Co, Cu, Fe, Ti, Al, In, Zr, Mo, Ta, W, V, Nb, Y and Pd.

7. The specimen according to claim 1 , wherein the specimen has a twinning stress between 0.05-0.1 MPa.

Assignees

• Ezer Yossef
• Sozinov Oleksii
• Straka Ladislav
• Soroka Aleksandr
• Lanska Nataliya
• Eto Magnetic Gmbh

Inventors

• Ezer Yossef
• Sozinov Oleksii
• Straka Ladislav
• Soroka Aleksandr
• Lanska Nataliya

Classifications

• H01F1/0308

  with magnetic shape memory [MSM], i.e. with lattice transformations driven by a magnetic field, e.g. Heusler alloys · CPC title

• C21D2211/001

  Austenite · CPC title

• C22C19/005

  with Manganese as the next major constituent · CPC title

• C22F1/006

  Resulting in heat recoverable alloys with a memory effect · CPC title

• C22C19/03

  based on nickel · CPC title