MnAl ALLOY

Patent metadata

Field	Value
Publication number	US-2020002790-A1
Application number	US-201816485595-A
Country	US
Kind code	A1
Filing date	Mar 9, 2018
Priority date	Mar 22, 2017
Publication date	Jan 2, 2020
Grant date	—

Abstract

An object of the present invention is to provide a Mn-based alloy exhibiting metamagnetism over a wide temperature range. A MnAl alloy according to the present invention exhibits metamagnetism and has crystal grains containing a τ-MnAl phase and crystal grains containing a γ2-MnAl phase. Assuming that the area of the crystal grains containing the τ-MnAl phase in a predetermined cross section is B, and the area of the crystal grains containing the γ2-MnAl phase therein is A, the value of B/A is 0.2 or more and 21.0 or less. When the ratio of the areas between the crystal grains containing the τ-MnAl phase and those containing the γ2-MnAl phase is controlled within the above range, metamagnetism is imparted to the MnAl alloy and, thus, it is possible to obtain metamagnetism over a wide temperature range, particularly, over a temperature range of −100° C. to 200° C.

First claim

1 . A MnAl alloy exhibiting metamagnetism comprising crystal grains containing a τ-MnAl phase and crystal gains containing a γ2-MnAl phase.

2 . The MnAl alloy as claimed in claim 1 , wherein a value of B/A is 0.2 or more and 21.0 or less, where an area of the crystal grains containing the τ-MnAl phase in a predetermined cross section of the MnAl alloy is B, and an area of the crystal grains containing the γ2-MnAl phase in a predetermined cross section of the MnAl alloy is A.

3 . The MnAl alloy as claimed in claim 2 , wherein the value of B/A is 1.0 or more and less than 4.0.

4 . The MnAl alloy as claimed in claim 1 , wherein an average crystal grain diameter of the crystal grains containing the τ-MnAl phase is 0.1 μm or more and 1.0 μm or less.

5 . The MnAl alloy as claimed in claim 1 , wherein when a composition of the MnAl alloy is expressed by Mn b Al 100-b , 45≤b<55 is satisfied.

6 . The MnAl alloy as claimed in claim 5 , wherein 45≤b<52 is satisfied.

7 . The MnAl alloy as claimed in claim 1 , wherein a magnetic structure of the τ-MnAl phase has an antiferromagnetic structure in a non-magnetic field state.

8 . The MnAl alloy as claimed in claim 7 , wherein when a composition of the τ-MnAl phase is expressed by Mn a Al 100-a , 48≤a<55 is satisfied.

Assignees

• Tdk Corp

Inventors

• SATOH Suguru

Classifications

• C22C22/00 Primary

  Alloys based on manganese · CPC title

• C22F1/18

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

• C22C1/02 Primary

  by melting {(C22C1/1036 takes precedence)} · CPC title

• C25C3/36

  Alloys obtained by cathodic reduction of all their ions · CPC title

• C25C3/30

  of manganese · CPC title