| 摘要 |
PURPOSE:To alleviate the deterioration in characteristics due to kneading with resin and pressure molding and to obtain a bond-type permanent magnet characterized by excellent orientation and excellent magnetic characteristics by applying a metal coating on the surface of crushed powder of R-Fe-B-based permanent magnet alloy having magnetic anisotropy, and thereafter forming a unitary body together with a binder. CONSTITUTION:A metal coating is applied on the surface of the crushed powder of R-Fe-B-based permanent magnet alloy (R is at least one kind of Y and rare earth elements) having magnetic anisotropy. Then, a unitary body is obtained together with a binder. For example, a magnetic field of 15KOe is applied on the fine powder of alloy having the compositions of 14% Nd, 15% Co, 2% Al, 6% B and Fe as a remainder. The powder is compressed and molded under the pressure of 1.5ton/cm<2>. The molded body is sintered at 1,080 deg.C in a vacuum. After the rapid cooling, the powder is crushed to the average particle diameter of 300mum. Vapor deposition of Al is performed on the surface of the powder. Then, two-stage heat treatments are performed at 900 deg.C and 600 deg.C. Then, powder is kneaded with 3weight% of epoxy resin. A magnetic field of 15KOe is applied, and the powder is compressed and molded under the pressure of 4ton/cm<2> in parallel with the direction of the magnetic field. Thereafter, curing is performed for 2 hours at 120 deg.C, and the bond magnet is obtained. |
