Methods of producing rare earth alloy magnet powder with superior magnetic anisotropy

A method of producing a rare earth alloy magnet powder having superior magnetic anisotropy and an aggregate of fine recrystallized structure of a R.sub.2 T.sub.14 M intermetallic compound phase, comprising the steps of:

• elevating a R--T--M--A--Mg alloy material from room temperature to an elevated temperature in the range of 50020 C. to 1000.degree. C. under a hydrogen atmosphere or a mixed gas atmosphere of hydrogen and an inert gas.
• subjecting said R--T--M--A--Mg alloy material to hydrogen-occluding treatment in which hydrogen is occluded in said R--T--M--A--Mg alloy material to promote phase transformation by maintaining said alloy material at said elevated temperature under a hydrogen atmosphere or a mixed gas atmosphere of hydrogen and an inert gas;
• subsequently subjecting said R--T--M--A--Mg alloy material to dehydrogenating treatment in which hydrogen is forcibly released from said R--T--M--A--Mg alloy material to promote phase transformation by maintaining said R--T--M--A--Mg alloy material at a temperature ranging from 500.degree. to 1,000.degree. C. in a vacuum atmosphere of less than 1 torr, cooling;
• and crushing,
• where, in said R--T--M--A--Mg alloy material:
• R is at least one rare earth element inclusive of Y;
• T is at least Fe selected from the group consisting of Fe, Co and Ni;
• M is at least B selected from the group consisting of B and C;
• A is 0.001 to 5.0 atomic % of one or more elements selected from the group consisting of Si, Ga, Zr, Nb, Mo, Hf, Ta, W, Al, Ti, and V;
• and
• said R--T--M--A--Mg alloy material contains from 0.001 to 0.03 atomic % of Mg.

A method of producing a rare earth alloy magnet powder having superior magnetic anisotropy and an aggregate of fine recrystallized structure of a R.sub.2 T.sub.14 M intermetallic compound phase, comprising the successive steps of:

• subjecting a R--T--M--A--Mg alloy material to hydrogen-occluding treatment in which hydrogen is occluded in said R--T--M--A--Mg alloy material to promote phase transformation by elevating the temperature from room temperature to a temperature ranging from 500.degree. to 1,000.degree. C. and maintaining said temperature in a hydrogen atmosphere at 1/76 to 5 atm or a mixed gas atmosphere of hydrogen at a partial pressure of 1/76to 5 atm and an inert gas;
• subsequently subjecting said R--T--M--A--Mg alloy material to dehydrogenating treatment in which hydrogen is forcibly released from said R--T--M--A--Mg alloy material to promote phase transformation by maintaining said R--T--M--A--Mg alloy material at a temperature ranging from 500.degree. to 1000.degree. C. in a vacuum atmosphere of less than 1 Torr;
• cooling;
• and crushing,
• where, in said R--T--M--A--Mg alloy material:
• R is at least one rare earth element inclusive of Y;
• T is at least Fe selected from the group consisting of Fe, Co and Ni;
• M is at least B selected from the group consisting of B and C;
• A is 0.001 to 5.0 atomic % of one or more elements selected from the group consisting of Si, Ga, Zr, Nb, Mo, Hf, Ta, W, Al, Ti, and V;
• and
• said R--T--M--A--Mg alloy material contains from 0.001 to 0.03 atomic % of Mg.

A method of producing a rare earth alloy magnet powder having superior magnetic anisotropy and an aggregate of fine recrystallized structure of a R.sub.2 T.sub.14 M type intermetallic compound phase, comprising the steps of:

• elevating a R--T--M--A--Mg alloy material from room temperature to a elevated temperature up to 500.degree. C. and maintaining said alloy material at the elevated temperature in a vacuum or inert gas atmosphere;
• subjecting said R--T--M--A--Mg alloy material to hydrogen-occluding treatment in which hydrogen is occluded in said R--T--M--A--Mg alloy material to promote phase transformation by elevating the temperature from room temperature to a temperature ranging from 500.degree. to 1,000.degree. C. and maintaining said temperature in a hydrogen atmosphere at 1/76 to 5 atm or a mixed gas atmosphere of hydrogen at a partial pressure of 1/76to 5 atm and an inert gas;
• subsequently subjecting said R--T--M--A--Mg alloy material to dehydrogenating treatment in which hydrogen is forcibly released from said R--T--M--A--Mg alloy material to promote phase transformation by maintaining said R--T--M--A--Mg alloy material at a temperature ranging from 500.degree. to 1,000.degree. C. in a vacuum atmosphere of less than 1 Torr;
• cooling;
• and crushing,
• where, in said R--T--M--A--Mg alloy material:
• R is at least one rare earth element inclusive of Y;
• T is at least Fe selected from the group consisting of Fe, Co and Ni;
• M is at least B selected from the group consisting of B and C;
• A is 0.001 to 5.0 atomic % of one or more elements selected from the group consisting of Si, Ga, Zr, Nb, Mo, Hf, Ta, W, Al, Ti, and V;
• and
• said R--T--M--A--Mg alloy material contains from 0.001 to 0.03 atomic % of Mg.