입계확산공정 Nd-Fe-B계 소결자석의 보자력 향상을 위한 중 희토류 저융점 확산염의 효과

Abstract

Effective low melting-point Dy-diffusion for grain boundary diffusion treatment for enhancing coercivity in NdFe-B-type magnet was found in the DyF3–LiF binary system. Efficacy of the low melting-point (DyF3–LiF) diffusion source as Dy-diffusion source for enhancing coercivity in the diffusion processed Nd-Fe-B-type magnet was investigated. Speedier and more profound coercivity enhancement in the Nd-Fe-B-type magnet was achieved by grain boundary diffusion using the low melting-point (DyF3–LiF) diffusion source with respect to solid DyF3 single salt. Since the liquid in the (DyF3–LiF) mixture contained plenty of Dy atoms already freed from DyF3 and they were in better contact with magnet, speedier and profuse diffusion of Dy atoms through Nd-rich grainboundary was possible in the magnet coated with low melting-point(DyF3–LiF) diffusion source.