Effects of Sintering Atmosphere on the Magnetic Properties of Sm(Co, Fe, Cu)₇ Permanent Magnet Alloy

Abstract

Sm (Co, Fe, Cu)₇ powder compacts were sintered in three different kinds of sintering atmospheres; i.e., hydrogen, argon and vacuum of 10^-5 Torr.
The remarkable contraction due to the liquid phase sintering occured at a sintering temperature higher than 1220°C, where the amount of shrinkage increased in the order of argon, vacuum and hydrogen atmos-phere.
Higher density specimen were obtained and the alignment ratio of the grains was successfully improved by the sintering in hydrogen atmosphere.
Therefore the use of the hydrogen atmosphere led to enhance the resultant magnetic properties of Sm(Co, Fe, Cu)₇ permanent magnet alloys.