M. F. Urbano, A. Coda, R. Giannantonio, SAES Getters S.p.A, Lainate, Italy

Summary: The functional characterization of SMA wires is mainly performed by measurement of specimen deformation under thermo-mechanical loading: stress-strain testing at constant temperature or thermal cycling under constant load are typical characterization techniques. Such kinds of tests are performed with standard instruments, whose main disadvantages are slow testing speed and lack of flexibility. In order to overcome these drawbacks, a novel instrument has been conceived. The instrument is able both to perform thermo-mechanical loading in a lot of different conditions with maximum flexibility and to simultaneously measure quantities like deformation, temperature, wire diameter and electrical resistivity. Thermal and mechanical loading can be applied gradually, in order to observe the material characteristics in quasi-static conditions, or impulsively, in order to appreciate dynamic phenomena. This paper reports a description of the instrument and a discussion of preliminary results. Particular focus will be devoted to the R-phase detection by resistance measurement, applying both heating and cooling cycles in different loading conditions. Preliminary experimental results will be compared with literature data.