Highly tunable, inexpensive and easily fabricated magnetocaloric materials

Patent metadata

Field	Value
Publication number	US-11851731-B2
Application number	US-201816350728-A
Country	US
Kind code	B2
Filing date	Dec 20, 2018
Priority date	Dec 28, 2017
Publication date	Dec 26, 2023
Grant date	Dec 26, 2023

Abstract

A method is provided of making a magnetocaloric alloy composition comprising Ni, Co, Mn, and Ti, which preferably includes certain beneficial substitutional elements, by melting the composition and rapidly solidifying the melted composition at a cooling rate of at least 100 K/second (Kelvin/second) to improve a magnetocaloric property of the composition. The rapidly solidified composition can be heat treated to homogenize the composition and annealed to tune the magneto-structural transition for use in a regenerator.

First claim

We claim:

1. A method of making a magnetocaloric alloy composition comprising Ni, Co, Mn, and Ti alloy represented by Ni 50-x Co x Mn 35 Ti 15 where x=10 to 15 comprising melting the alloy to provide an alloy melt and rapidly solidifying the alloy melt at a cooling rate of at least 100 K/second (Kelvin/second) to yield a rapidly solidified alloy having a B2 crystal structure and exhibiting a magneto-structural transition between a ferromagnetic phase and an antiferromagnetic phase that produces, as-rapidly solidified, a magnetocaloric entropy change at about room temperature in a magnetic field of 1.5 T to 2 T that is greater than that of a same alloy that is not rapidly solidified.

2. The method of claim 1 wherein the alloy melt is rapidly solidified by melt spinning, splat quenching, gas atomization, selective laser melting, or 3D printing.

3. The method of claim 1 including the further step of heat treating the rapidly solidified alloy to homogenize the alloy composition.

4. The method of claim 1 including the further step of annealing the rapidly solidified alloy at a temperature and for a time to adjust a magneto-structural transition temperature.

5. The method of claim 1 wherein the rapidly solidified alloy exhibits a chemically homogeneous microstructure or nanostructure.

6. The method of claim 1 that produces the rapidly solidified alloy that exhibits a magnetocaloric entropy change at room temperature in a magnetic field of 1.5 T to 2 T that is about three times or more greater than that of a same alloy that is arc-melted and heat treated bulk alloy.

Assignees

• Univ Iowa State Res Found Inc

Inventors

• Bez Henrique Neves
• Biswas Anis
• Pathak Arjun K
• Mudryk Yaroslav
• Zarkevich Nikolai A
• Balema Viktor
• Pecharsky Vitalij K

Classifications

• C22C19/03

  based on nickel · CPC title

• C22C19/005

  with Manganese as the next major constituent · CPC title

• C22F1/10

  of nickel or cobalt or alloys based thereon · CPC title

• C22C1/023 Primary

  Alloys based on nickel · CPC title

• C21D8/1211

  Rapid solidification; Thin strip casting · CPC title