Study on Properties of MnAlC Magnetic Powder and Bulk

The magnetic properties of MnAl are improved by doping C to stabilize the magnetic phase. In this work, a method to prepare high performance MnAlC magnetic powder and bulk is presented. This enhances the potential of MnAl to replace rare earth permanent magnet material. The phase composition, microstructure and magnetic properties of the samples were measured and studied. After annealing and tempering, the ingot transformed into a structure dominated by r-phase. The coercivity of the powder increases with the increase of grinding time, while the saturation magnetization decreases. The maximum of saturation magnetization obtained was 72.7 emu/g, and the maximum of coercivity was 3665 Oe. Following magnetic field orientation, the coercivity of the MnAlC magnetic powder reached 5862 Oe and obtained larger remanence ratio, indicating the anisotropic magnetic powder was obtained. Dense bulk of MnAlC was successfully prepared by hot-pressing.