Sm(Co, Fe, Cu, Zr)z magnets fabricated by simple processing

Optimization studies in Sm(Co, Cu, Fe, Zr)(z) magnets for high-temperature applications led to some compositions which develop their high coercivity with simple processing. Homogenized magnets with higher Cu and Zr content acquire a coercivity of above 20 kOe after a short aging (3 h) at 850 degrees C without the traditional slow cooling to 400 degrees C which is required for the commercial magnets. Microstructure studies showed that the homogenized magnets consist of a mixture of Sm(Co, Cu)(5) precipitates in a disordered 2:17 matrix as compared to a uniform and featureless microstructure of the traditional homogenized magnets. Because of this, the time required for the full development of uniform cellular and lamellar structures with the right microchemistry is much shorter in the magnets. (C) 2000 American Institute of Physics. [S0003-6951(00)01629-6].