PRODUCTION OF RARE EARTH-IRON BASED SINTERED PERMANENT MAGNET AND MOLDING MATERIAL

摘要

PURPOSE: To enable continuous molding without applying a mold release agent to metal molds in production of a sintered permanent magnet by press molding and sintering of rare earth-iron-boron based alloy powder. CONSTITUTION: The molding material formed by uniformly mixing at least one kind of boric ester based compds. (e.g. tributyl borate) at a ratio of 0.01 to 2wt.% as a lubricant with alloy powder composed mainly of 10 to 30atm.% R (where R is at least one kind selected from rare earth elements including Y), 2 to 28atm.% B and 65 to 82atm.% Fe (where up to 50atm.% of the Fe content can be substd. with Co) prior to, during or after pulverization thereof is used for press molding. As a result, the continuous molding is possible without executing mold lubrication and the orientability of the alloy powder is improved at the time of the press molding under magnetic impression. The magnet characteristics and more particularly the residual magnetic flux density and max. energy product are improved.