Magnetic Properties of Ga-Added Nd-Fe-B HDDR Powders

Abstract

The effect of Ga addition on the enhancement of coercivity in HDDR-treated Nd-Fe-B powders, was investigated. Microstructural observation revealed that Ga addition suppresses grain growth of recombined Nd₂Fe₁₄B during the DR process. Analysis using the microstructural parameters in Kronmmarüllers equation shows that the α _K value of Ga-added samples (0.48) is larger than that of ternary samples (0.12), which suggests that Ga leads to the development of reduced surface anisotropy in the recombined Nd₂Fe₁₄B grains.