Microstructure and magnetic properties of (Mn54Al46)98C2 magnets fabricated by liquid-phase sintering with the Mn65Ga35 as an additive

Abstract

MnAl(C) alloys are widely considered as potential candidates of rare earth-free permanent magnets. Fabrication of MnAl(C) magnets remains an intensive research topic. In this work, liquid-phase sintering is primarily explored to prepare MnAl(C) magnets by sintering (Mn54Al46)98C2 with Mn65Ga35 as an additive. The sintering temperature of 1273 K ensures the Mn65Ga35 in liquid-state and (Mn54Al46)98C2 in solid-state. The liquid-phase sintering leads to a noticeable densification effect on the magnets, in which the internal porosity is significantly reduced. As the weight percentage of Mn65Ga35 increases from 0 wt.% to 40 wt.%, the remanence magnetization μ0Mr increases from 1.44 kGs to 1.83 kGs, the coercivity Hc increases from 1.08 kOe to 1.52 kOe, and the energy product (BH)max increases from 0.25 MGOe to 0.45 MGOe. The Hc increase is explained based on the nucleation model. This work might provide a possible approach to fabricate MnAl(C) magnets.