HIGH-PERFORMANCE NDFEB MAGNETS

Although the production and applications of NdFeB magnets have increas ed enormously in the last decade because of their outstanding magnetic properties at room temperature, some applications were limited becaus e of poor thermal stability and corrosion resistance. To address these problems, there have been many efforts and much progress. In many ins tances, the alloy modifications produced an improvement of some charac teristics but only at the expense of other characteristics. It is ther efore necessary to find a method (or alloy) for improving the thermal stability, coercivity, and corrosion resistance without sacrificing pe rformance. We have found that the proper control of very small amounts of Cu, Co, and O in (Nd, Dy)FeB alloys substantially improves the coe rcivity, high-temperature capabilities, and corrosion resistance witho ut a reduction of remanence. As a result, a high performance NdFeB mag net with excellent temperature stability and corrosion resistance was developed. (C) 1996 American Institute of Physics.