ORDER PROCESSES IN CU-ZN-AL SHAPE-MEMORY ALLOYS - QUANTITATIVE APPROACH TO M-S VALUES BY RESISTANCE MEASUREMENTS

Analysis of the experimental results on Cu-Zn-Al shape memory alloys i ndicates that the transformation temperatures (for instance, M-s) fluc tuate in long-term records. continuous measurements of electrical resi stance R (five significant figures) ale made with controlled and progr ammed temperature (resolution 0.005 K). The experimental analysis sugg ests a partitioning of resistance into two additive contributions: pho non and order (or R). The time behaviour of R* represents the depende nce of M-s on time. The results indicate that the effects of time and temperature in the austenite phase can be represented by two independe nt differential equations: the long-time fluctuations in the transform ation temperature are predictable and the uncertainty reduces to +/-0. 15 K.