AC calorimetric study of the thermoelastic martensitic transformation in Cu-Al-Ni alloys

We present an accurate study by AC calorimetry on the thermoelastic martensitic transformation in Cu-Al-Ni shape memory alloys, both under quasi-isothermal conditions and by using a dynamic method. The AC calorimetry results suggest that the martensitic transformation exhibits some kinetic effects strongly dependent on the temperature rate, in agreement with internal friction results. Calorimetric results obtained by DSC do not exhibit this behaviour, but dynamic measurements obtained under oscillating fields show a net dependence on the temperature rate.