On the Relation between the Matensite Start Stress and the Temperature in Single Crystalline Cu-11.5wt%Al-5.0wt%Ni Shape Memory Alloy
General form of the well known-relation between the critical stress, necessary to start/finish martensite/austenite formation, and the test temperature is simply and plausibly obtained from our local equilibrium model of phase transformation , and compared to the classical forms of the Clausius-Clapeyron relation. Although in general, first of all because of the stress and temperature dependence of the transformation strain, εtr, the above relations are not inevitably linear, in most of the cases linear functions were observed. Using the results of our experiments carried out on single crystalline Cu-11.5wt%Al-5.0wt%Ni samples for the strain stress hysteretic loops at constant temperatures , the slopes of these functions are analyzed on the basis of the relations obtained and it is shown that these are different due to different stress dependence of the elastic energy contributions.
P. J. Szabó and T. Berecz
T. Y. Elrasasi et al., "On the Relation between the Matensite Start Stress and the Temperature in Single Crystalline Cu-11.5wt%Al-5.0wt%Ni Shape Memory Alloy", Materials Science Forum, Vol. 659, pp. 399-404, 2010