Permanent magnet material, production manner null of cooling roller and permanent magnet material for permanent magnet material production

摘要

PURPOSE:To obtain a permanent magnet material having superior magnetic characteristics by cooling a molten alloy having a specified compsn. by contact with the surface of a cooling roll and limiting the average surface roughness of the cooled alloy along the center line. CONSTITUTION:A molten alloy contg. one or more kinds of rare earth elements including Y, Fe or Fe and Co and B is spouted from a nozzle and cooled from one direction or opposite two directions by contact with the surface of a rotating cooling roll to produce a permanent magnet material. At this time, a roll having 0.07-1.5mum average surface roughness Ra along the center line is used as the cooling roll. The roughness Ra of the cooled alloy is regulated to 0.05-1.5mum and a permanent magnet material whose roughness Ra is below that of the cooling roll is produced.