Model free energy,mechanics, and thermodynamics of shape memory alloys

The shape memory effect (SME) in alloys is due to a first order martensitic phase transition. Based on Landau's theory a phenomenological model free energy function is presented which accounts for the SME. The mechanical and thermodynamical consequences of the model (such as stress-strain curves, elastic constants, and the latent heat of the phase transition) are discussed. Comparison with experiments yields the four involved parameters for the alloy Au₂₃ Cu₃₀ Zn₄₇.