PURPOSE: To obtain permanent magnet material superior in magnetic characteristic such as coersive force, residual magnetic flux density and energy product, by sintering and solid soln. heat treating rare earth Co intermetallic compd. having a prescribed component compsn., then rapidly cooling, next, repeating heat treatments composed of heating and cooling at range between prescribed temps. at ≥2 times.
CONSTITUTION: Rare earth Co intermetallic compd. composed of by weight 22W26% R (one kind or more among rare earth element), 2W10% Cu, 6W35% T (one kind or more among Fe, Ni, Mn and Cr), 0.5W6% M (combination of Zr and/or Hf and one kind or more among Ti, Nb, V and Ta) and the balance Co is treated as follows. Namely, the intermetallic compd. is sintered and soln. heat treated at ≥1,000°C, then rapidly cooled to 750W950°C generally about by 1W300°C/sec rate. Next, the compd. at the temp. is subjected to heat treatment in which it is cooled to ≤700°C at ≥2 times. Thereby, the titled material having magnet characteristic improved markedly compared with conventional ageing treatment in high Fe quantity and low Cu quantity is obtd.
SATO KAZUO
KATO YOSHIO
| JPS5825403A | 1983-02-15 | |||
| JPS53137022A | 1978-11-30 |