Order processes in Cu-Zn-Al shape memory alloys -: Quantitative approach to Ms values by resistance measurements

Analysis of the experimental results on Cu-Zn-Al shape memory alloys indicates that the transformation temperatures (for instance, M-s) fluctuate in long-term records. continuous measurements of electrical resistance R (five significant figures) ale made with controlled and programmed temperature (resolution 0.005 K). The experimental analysis suggests a partitioning of resistance into two additive contributions: phonon and order (or R*). The time behaviour of R* represents the dependence of M-s on time. The results indicate that the effects of time and temperature in the austenite phase can be represented by two independent differential equations: the long-time fluctuations in the transformation temperature are predictable and the uncertainty reduces to +/-0.15 K.