Corrosion-resistance Nd-TM-B magnet

Abstract

A search for compatibility between magnetic properties and corrosion resistance was made by studying a pseudoternary system, Nd-(Fe/sub 1-x-y/Co/sub x/Ni/sub y/)-B, of melt-spun ribbons and sintered bodies. It was found that the double substitutions with 0.2<or=x<or=0.45 and 0.05<or=y<<0.25 in the composition of the ordinary Nd-Fe-B magnet yield good corrosion resistance and also preserve moderate coercivity values. A further small substitution of Ti atoms for Fe atoms enhances the coercivity and makes the demagnetization curve rectangular. For example, (BH)/sub max/ and /sub i/H/sub c/ in sintered magnets of Nd/sub 15/(Fe/sub 0.585/Co/sub 0.3/Ni/sub 0.1/Ti/sub 0.015/)/sub 77/B/sub 8/ amounted to 34 MGOe and 10.4 kOe, respectively.<<ETX>>