High-performance Sm2Co17 based alloy with enhanced magnetic properties and improved corrosion resistance

Abstract

The magnetic properties, microstructures and corrosion resistance of Sm2Co17 based sintered permanent magnets with the nominal composition Sm(CobalFe0.125Cu0.08Zr0.06)7.4 have been systematically investigated. The Sm2Co17 based magnets were prepared by a traditional powder metallurgy method, where the techniques of making powder were ball-milling and jet-milling, respectively. An enhanced magnetic properties has been obtained for the magnet made of jet-milling powder, where the intrinsic coercivity Hcj increases from 2270 to 2879 kA/m, the maximum magnetic energy product (BH)max from 217 to 235 kJ/m3 with a small decrease in remanence Br only. Besides, a remarkably improvement in electrochemical stability and corrosion resistance for the magnet with the jet-milling powder, which is mainly attributed to the magnet obtains a uniform continuous cellular structure with the smaller cell size and the homogeneous cell boundary phase.