Thermodynamic calculation of energy consumed for boundary friction during martensitic transformation in single crystal Ni2MnGa
Ni2MnGa单晶马氏体相变过程摩擦耗能的热动力学计算

Based on the boundary friction phenomenological theory,a general equation for calculating the thermodynamic parameters of Ni2MnGa system was deduced.According to the measured results of the ac magnetic susceptibility or strain during the martensitic transformation for three non-stoichiometric Ni2MnGa single crystal samples with martensitic transition occurring at temperatures below,near,and above room temperature,respectively,the energies consumed for boundary friction in the three samples during their martensitic transformations were calculated using the general equation.It was also indicated that the thermal hysteresis of martensitic transformation originates from the friction of phase boundary motion;moreover,the large differences of the energy consumed for boundary friction and the thermal hysteresis result from the different structures of martensites produced for the three samples during the martensitic transformation.