MANUFACTURE OF MATERIAL FOR RARE EARTH PERMANENT MAGNET

PURPOSE:To obtain a magnet excellent in magnetic property by making impurities float as slag and also checking the invasion of Ca and O2 when dissolving materials such as Se, Y, etc., and/or Co, Fe, etc., and also dissolving a block- shaped compact consisting of Dy-Fe so as to make them into specified molten alloy. CONSTITUTION:DY2O3, Fe, metal Ca are mixed, and then are reduced by heating to produce Dy-Fe alloy, and this is classified so that the products 10mm in grain diameter may exist 90wt.% or more. Next, this is made into a block- shaped compact at formation pressure of 0.3 ton/mm or more, and it is made to contain an R and/or M ingredient including the Dy and Fe within this compact, and these are dissolved and made into alloy. Hereupon, R is one kind or two kinds out of Se, Y, LA, etc., and M is one kind or two kinds out of Co, Fe, Ni, etc. By doing it this way, CaO contained as an impurity floats as slag, and also Ca and O2 do not mix in RM alloy, and the surface oxide film existing at the shell also floats as slag.