Abstract
To examine the possibility of using segregated master ingots in the HDDR process, Nd-Fe-B HDDR powders were made from ingots with different levels of homogeneity, and their magnetic properties and structures were evaluated. As the ingots were homogenized, their anisotropy deteriorated and the coercive force increased. In addition, improvement of their magnetic properties was attempted by using intermediate Ar (IA) treatments between the HD and DR processes. As a result, the effect of the IA treatments was confirmed clearly, and good magnetic properties of Br = 1.23 T, HcJ = 848kA/m, and (BH)max = 238kJ/m3 were obtained; these are close to those of commercial HDDR powder (MQA-T).
