| 摘要 |
PURPOSE:To make it possible to improve magnetic characteristics and adhesion, by absorbing hydrogen into rare earth alloy beforehand, and crushing the alloy into fine powder in a hydrogen gas or inactive gas atmosphere in a container without taking out the alloy. CONSTITUTION:A stainless steel ball-mill mixing container 1, wherein crushing balls 4 are put beforehand and evacuation and gas sealing can be performed, is used. Hydrogen gas is introduced in the container 1 and absorbed in an alloy mass A. The pressure in the container 1 is adjusted at a normal pressure with the hydrogen. Or the remaining hydrogen is substituted with inactive gas. Then the alloy mass A is crushed into fine powder. Then heat treatment is performed so that the temperature is increased to a range of 200-600 deg.C and kept for 30-240min. The absorbed hydrogen is completely discharged. Distortion in the crystal lattice is removed. Thus chances for contacting oxygen and carbon are decreased. The fine powder, whose size is the same, is obtained. The regular crystal lattice whose shape is well ordered, is formed. The magnetic char acteristics of a magnet are improved. The surfaces of the metal particles are activated, and the adhesion force of the magnet is enhanced. |
