MICROSTRUCTURE AND PHASE TRANSFORMATION IN Ni₅₀Mn₄₀Sn₁₀ SHAPE MEMORY ALLOY

Abstract

In the present work, a ternary Heusler alloy of composition Ni₅₀Mn₄₀Sn₁₀ with a high martensitic transformation temperature has been prepared by arc-melting technique. The crystal structure of the obtained alloy is investigated by X-ray diffraction. The microstructure of the specimen sintered at 950 °C for 72 h followed by ice-water quenching shows needle-like martensitic structure. Energy dispersive spectroscopy is utilized for compositional study. The differential scanning calorimetry result shows that the alloy undergoes a martensitic transformation at 190 °C upon cooling. The M–H curve suggests paramagnetic nature of the martensite phase at room temperature. The present alloy system has a great potential to be used for high-temperature shape memory applications. Experimental data of this study may be useful for developing Ga-free high-temperature shape memory alloys.