Effect of crystal orientation relationship on anisotropic inducement in the HDDR treated Nd-Fe-B alloys

Summary form only given. Nd-Fe-B powders produced using HDDR process, are useful for the production of high performance anisotropic bonded magnets. Recently, the authors clarified the temperature dependence of the recombination pressure of the Nd/sub 2/Fe/sub 14/B compound, and established the necessary HDDR treatment conditions for the production of high performance anisotropic ternary alloy powders. The newly proposed HDDR treatment was a combination of heat treatments, at hydrogen pressures close to the recombination pressure of the Nd/sub 2/Fe/sub 14/B compound, in both the disproportionation and recombination stages. Namely, the combination of v-HD or l-HD (heating in vacuum or in a low H/sub 2/ pressure, respectively, during the Hydrogenation Disproportionation stage), and s-DR (heating in Ar or in hydrogen with hydrogen pressure close to the recombination pressure for 10 min, at the start of the Recombination) treatments. In this investigation, using anisotropic sintered bodies, the crystal orientation relationship between the parent Nd/sub 2/Fe/sub 14/B phase and the disproportionated mixture during the new HDDR treatment was investigated by using XRD and TEM, and its effect on the anisotropic inducement was discussed.