METHOD FOR CONTROLLING STRUCTURE OF RARE EARTH ELEMENT-CONTAINING ALLOY, POWDER MATERIAL OF THE ALLOY AND MAGNET USING THE SAME

摘要

An object of the present invention is to provide a method for controlling an internal metallographic structure of an alloy, particularly the distribution of R-rich phase; in order to achieve the object, the present invention provide a method for controlling the metallographic structure of an alloy containing a rare earth element, which comprises the steps of: melting said alloy containing a rare earth element in vacuum or under an inert gas; pouring a molten metal obtained by melting said alloy onto a rotatable roll which is rotating and being cooled, to thereby cool the molten metal for solification, said pouring being performed in a vacuum chamber or a chamber purged by an inert gas; forming a strip of said metal through solidification; immediately after solidification, reducing said resultant solidified strip into flakes; collecting said resultant fragmented alloy flakes in a receptacle; and controlling the cooling rate of said fragmented alloy flakes by means of a cooling medium.