| 摘要 |
PURPOSE:To obtain a permanent magnet having the energy product which is extremely high as compared to the conventional permanent magnet by compacting ferrous alloy powder contg. a prescribed ratio each of a rare earth element and B with a press in a magnetic field then solidifying and molding the powder by explosive compression and subjecting further the molding to an aging treatment. CONSTITUTION:The alloy powder contg. 12-21at% rare earth element and 4-25at% B and consisting of the balance substantially Fe is compacted with the press in the magnetic field having preferably about 10kOe intensity. The green compact is then packed into a metallic pipe 1 and after both ends of the pipe 1 are hermetically closed by a metallic plug 3a having a conduit 2 for evacuation and a metallic plug 3b having no conduit, the inside of the pipe 1 is evacuated to about 10<-6>mmHg, then the pipe 2 is closed. Such pipe 1 is installed as the concentrical axis into a paper cylinder 4 and rubber putties 5 are attached to the top and bottom ends of the pipe 1; thereafter explosives 6 are packed between the pipe 1 and the cylinder 4 and the explosives 6 are exploded by an electric detonator 7, by which the explosive compression is executed. The compressed body is then subjected to the aging treatment, by which the intended permanent magnet having the high energy product is obtd. |
