PURPOSE: To obtain readily a high performance magnet by repeating elevation and lowering of the temperature between high temperature region and low temperature region of two phase separation temperature region for appriate period after sintering process to reduce Cu amount dependency, when Ce rare earth magnet is to be obtained.
CONSTITUTION: When rare earth magnet represented by a general formula R(Co, Cu,Fe,X)z where R=Ce, CeMM; X=one or more of Ti, Nb, Zr, Mo, V, W, and Ta, z=5.4 to 7.5 is produced, the magnet is processed as follows. Milling the alloy by conventional method, press molding in a magnetic field, and sintering, then heat treating repeatedly by elevating and lowering the temperature between high temperature region and low temperature region selected appropriately from the two phase separation temperature region for appropriate period. Where it is desirable to heat treat repeatedly after sintering continuously or from heat treatment starting temperature of 600°C. Cu amount dependency of the magnetic property is reduced by this treatment.
YAMADA MASAKAZU
INOMATA KOUICHIROU
