Calorimetric Studies of the Martensitic Transformation in Ni-Mn-Ga Ferromagnetic Shape Memory Alloys

摘要

The thermal characteristics of the martensitic transformation in Ni-Mn-Ga alloys were studied using differential calorimetry in order to assess the influence of quenching and the heating rate on the resulting thermal properties. Following solution annealing at 850°C and water quenching, sharper peaks are observed. The martensitic microstructure was observed by both optical and electron microscopy, showing typical needle like morphology and the martensitic transformation kinetics was analyzed using the Kissinger approach.