Elevated temperature study of Nd-Fe-B-based magnets with cobalt and dysprosium additions

This paper discusses the elevated temperature performance of Nd-Fe-B magnets containing 0–15 wt. % cobalt substitutions for iron and 0–10 wt. % dysprosium substitutions for neodymium. Test samples were prepared using conventional powder metallurgy techniques. Elevated temperature hysteresis loop and open-circuit measurements were performed on the samples to investigate irreversible losses and long term aging losses at 150 °C. Magnets with high amounts of both cobalt and dysprosium exhibited lower losses of coercivity and magnetization. Dysprosium had more influence on the elevated temperature performance of the material than did cobalt.