| 摘要 |
PURPOSE:To obtain a permanent magnet characterized by high coercive force, high magnetic flux density, excellent oxidation resistance and excellent machinability without necessarily requiring rare earth metal and B by providing a material which comprises Zr of specified atomic % in atomic fraction and substantial amount of Co for the remaining part and wherein the average crystal grain diameter in main phase is within a specified range. CONSTITUTION:The material of this permanent magnet comprises Zr of 6-25 atomic % in atomic fraction and the substantial amount of Co for the remaining part. The average crystal grain diameter in main phase is 0.01-20mum. For example, at first, Zr and Co are compounded so that the Zr is 14.6atom.% and the remaining part is the Co. Then, arc melting is performed by using a water-cooled coper boat in an Ar atmosphere. Then, the obtained alloy undergoes super quenching by a single roll method using a copper roll having the diameter of 300mm which is rotated at the high speed of 30m/sec in the Ar atmosphere. Thus, the ribbon-shaped alloy which has the average grain diameter of 0.1mum in main phase and is cooled at the super quench speed is manufactured. Thereafter, the alloy is heat-treated in a vacuum at 500-700 deg.C for 10 minutes and crushed into the grain diameter of 60mum, and the alloy powder is obtained. Epoxy resin is mixed. Then the powder is compressed and molded, and curing is further performed at 120 deg.C. Thus the bond magnet is manufactured. |
