Estimation of driving force for martensitic transformation in (Ni52.5Mn23.5Ga24)100−xCox alloys

(Ni52.5Mn23.5Ga24)100−xCox (x = 2, 4, 6, 8) alloys were prepared for the determination of their characteristic phase transformation temperatures (Ms, Mf, As, Af) and high temperature yield strength of the parent phase. The driving force for the martensitic phase transformation in these alloys was estimated from thermodynamic point of view by taking into account the contributions of the shape deformation and the twin formation accompanying the martensitic phase transformation to the energy required to initiate the transformation; and a positive linear relationship between the driving force and the yield strength of the parent phase at Ms temperature was established.

Research highlightsThe driving force for the martensitic phase transformation in (Ni52.5Mn23.5Ga24)100−xCox (x = 2, 4, 6, 8) alloys was estimated from thermodynamic point of view by taking into account the contributions of the shape deformation and the twin formation accompanying the martensitic phase transformation to the energy required to initiate the transformation; and a positive linear relationship between the driving force and the yield strength of the parent phase at Ms temperature was established.