Spark plasma sintering of Mn–Al–C hard magnets

Structural and magnetic characterization of isotropic Mn-Al-C bulk samples obtained by spark plasma sintering (SPS) is reported. This technique, to our knowledge, has not been used for preparation of Mn-Al-based permanent magnets yet. Transformation from the parent epsilon-phase to the ferromagnetic tau- phase occurred on heating in the process of sintering. The phase constitution of melt-spun precursors and consolidated samples was determined by X-ray diffraction. Magnetic hysteresis loops were recorded using a vibrating sample magnetometer. The compositional dependence of coercivity, magnetization and density of sintered materials is analyzed. To combine good magnetic properties with proper densification, further optimization of the production parameters is necessary.