MnAl alloy, particles thereof, and method for production
An alloy represented by the formula (Mn x Al y )C z , the alloy being aluminum (Al), manganese (Mn), and carbon (C), and optionally unavoidable impurities; wherein x=56.0 to 59.0 y=41.0 to 44.0 x+y=100, and z=1.5 to 2.4. The alloy is highly suitable for forming the ε and τ phase in high purity and high microstructural homogeneity. A method for processing an alloy of formula (Mn x′ Al y′ )C z′ , wherein x′=52.0 to 59.0, y′=41.0 to 48.0, x′+y′=100, and z′=0.1 to 3.0, the process including providing the raw materials of the alloy, melting the raw materials, and forming particles of the alloy by gas atomization of the molten alloy.
1. A method for producing or treating an alloy having a composition of formula (II)
(Mn x′ Al y′ )C z′ (II)
wherein
x′=52.0 to 59.0
y′=41.0 to 48.0
x′+y′=100, and
z′=0.1 to 3.0
wherein the ratio of x′ to z′ (x′/z′) is in the range of 26 to 30,
the alloy consisting of Mn, Al, C, and optionally unavoidable impurities, the process comprising:
a. optionally, providing the raw materials of the alloy, melting the raw materials, and forming particles of the alloy by gas atomization of the molten alloy;
b. optionally, performing a heat treatment on the alloy at 900-1200° C.;
c. milling the alloy represented by formula (II) at a temperature of −20° C. or below-; and
d. performing a heat treatment on particles of the alloy represented by formula (II) at a temperature of 900 to 1000° C. for a time of 0.5 to 20 minutes,
wherein the milling c. is performed prior to the heat treatment d.
2. The method according to claim 1 , wherein
x′=56.0 to 59.0
y′=41.0 to 448.0
x′+y′=100, and
z′=1.5 to 2.4.
3. The method according to claim 1 , wherein z′=1.7 to 2.2.
4. The method according to claim 1 , wherein x′=56.5 to 58.5 and y′=41.5 to 43.5.
5. The method according to claim 1 , wherein x′=57.0 to 58.0 and y′=42.0 to 43.0.
6. The method according to claim 1 , wherein the ratio of x′ to z′ (x′/z′) is in the range of 27.5 to 30.
7. The method according to claim 1 , wherein the alloy has a & phase content of 90% by mass or more.
8. The method according to claim 1 , wherein all of steps a. to d. are performed.
9. The method according to claim 1 , wherein step a. is performed.
10. The method according to claim 1 , wherein step c. is performed at a temperature of −100° C. or lower.
11. The method according to claim 1 , wherein step c. is performed at a temperature of −150° C. or lower.
12. The method according to claim 1 , wherein step d. is performed for 5 to 15 minutes.
13. An alloy obtainable by the method according to claim 1 .
14. The alloy according to claim 13 , which has a content of the t phase of 80% or more.
15. The alloy according to claim 13 , which has a saturation magnetization M S of 100 emu/g or more.
16. The alloy according to claim 13 , which is in the form of particles having a median particle diameter D50, as determined by a light scattering method, of 5000 μm or less.
17. The alloy according to claim 13 , which is in the form of particles having a median particle diameter D50, as determined by a light scattering method, of 200 μm or less.
18. The alloy according to claim 13 , which is in the form of particles having a median particle diameter D50, as determined by a light scattering method, of 100 μm or less.
19. The alloy according to claim 13 , wherein the alloy is in the form of particles.
20. The alloy according to claim 13 , wherein the alloy has a saturation magnetization M S of 100 emu/g or more.