PROCESS FOR MANUFACTURING ALNICO SYSTEM PERMANENT MAGNET

摘要

A process for manufacturing an Alnico system permanent magnet is disclosed in which the alloy powder of the Alnico system having the proper composition is manufactured through a rapid solidification process, so that the crushability and the formability should be superior, the sintered density should be high, and the magnetic properties should be excellent, as well as cheap in its manufacturing cost and simple in its manufacturing process. An alloy of Alnico system is subjected to a rapid solidification with a spinning solidifier wheel speed of 6 - 40 m/sec, thereby manufacturing a micro-crystalline rapidly solidified powder. The powder is ground into a finer powder, and then a press-forming is carried out. Then a sintering is carried out at a temperature of 100 - 1350 DEG C for 0.5 - 4 hours. Then based on a single heat treatment, an external magnetizing force of 1 - 15 kOe is applied in a temperature range of 600 - 1000 DEG C, thereby carrying out a heat treatment under a magnetizing force. Thereafter, an aging heat treatment is carried out at a temperature of 500 - 700 DEG C for 1 - 10 hours, thereby magnetizing the formed body.