摘要 |
PURPOSE:To obtain a permanent magnet having high energy product by containing mainly Sm2Co17 type crystal including Sm, Co, Cu, Fe, Si with 21-28wt% of Sm and transforming the crystal in macrostructure at the time of casting an ingot and magnetizing it. CONSTITUTION:An Sm2Co17 type crystal containing Sm, Co, Cu, Fe, Si with the Sm of 21-28wt% is placed in an alumina crucible, and is molten by a high frequency melting furnace. The molten metal is cast in an iron mold at 1,550 deg.C to produce a macrostructure formed on a chilled layer A, a columnar structure B and an isometric structure C. Thereafter, ingots are cut from the ingots A-C, and are subjected to solid solution treatment at 1,130-1,180 deg.C, are then aged at 800 deg.C, and magnetically hardened. The ingot is then pulverized to powder having mean grain size of 100mum, the powder is mixed with organic binder, the mixture is pressed in a magnetic field, is then heated, and cured to produce a desired magnet. |