Melt-spun MnAl alloys: Synthesis and characterization insights

In this study, we investigated the influence of cooling rate on the microstructure and magnetic properties of Mn₅₄Al₄₆ alloy. We obtained melt-spun ribbons at linear wheel speeds of 15 and 25 m/s followed by thermal annealing to promote the ε → τ phase transformation. X-ray diffraction (XRD) confirmed the τ phase presence in the annealed ribbons. Energy Dispersive Spectroscopy (EDS) was used to verify the stoichiometric composition. Magnetic properties were determined by vibrating sample magnetometry (VSM), for which the coercive field (H_c) values from 1600 up to 1820 Oe at room temperature (300 K), together with a saturation magnetization (M_s) ranging from 7.2 to 85 emu/g. The results of this work will help understand the influence of cooling rates with the magnetic properties, which will allow the optimization of rapid solidification processing routes for the fabrication of RE-free permanent magnetic material based on τ-MnAl.