Phase-Field Simulation on the Formation of Grain Boundary Phase in Neodymium Hard Magnet

Abstract

The non - equilibrium phase - field method which has recently been proposed by Steinbach et al . was slightly modified, and the improved method was applied to the formation process of grain boundary phase （ GBP ） in the Nd 2 Fe 14 B polycrystalline microstruc ture of Fe - Nd - B hard magnet. In particular, we focused on the temporal evolution of morphological changes of GBP in this study, and the results obtained are as follows: （ 1 ） The Nd Fe grains are partially covered with GBP at early stage of aging, however the coverage decreases with aging by Ostwald ripening among GBPs. （ 2 ） The coverage area by GBP increases with increasing average composition of Nd in alloy. （ 3 ） The interfacial energy density between GBP and Nd 2 Fe 14 B phase greatly affects the morphological change of GBP. ［ doi:10 . 2320 / jinstmet.JA201603 ］ Published ）