Phase-transformation studies on mn-al-c alloy, by dsc and electrical-resistivity measurements

Phase transformation studies carried out on Mn-Al-C permanent magnet alloy employing DSC and electrical resistivity measurements, are reported and discussed. The transformation of the hexagonal Mn-Al phase (disordered and non-magnetic) to the ferromagnetic fct phase proceeds via the formation, in at least two stages, of the ordered orthorhombic phase. The activation energy for the formation of the fct phase is approximate to 34.65 kcal/mol. Microstructural changes occurring at various stages of the transformation are also studied.