On the kinetics of an austenite → martensite phase transformation induced by impact in a Cu-Al-Ni shape-memory alloy

The kinetics of a propagating phase boundary in a single crystal of Cu-Al-Ni is determined. As particles cross this moving interface, they transform from austenite to β'_1-martensite; the former phase is cubic, while the latter is monoclinic. The data that are used in this paper were obtained by Escobar and Clifton (Escober, J. C. and Clifton, R. J., On pressure-shear plate impact for studying the kinetics of stress-induced phase transformations. J. Mater. Sci. Engng, 1993, A170, 125–142; Escober, J. C. and Clifton, R. J. Pressure-shear impact-induced phase transitions in Cu-14.4Al-4.19Ni single crystals. SPIE, 1995, 2427, 186–197) and Escobar (Escobar, J. C., Plate impact induced phase transformations is Cu-Al-Ni single crystals. Ph.D. dissertation, Brown University, Providence, RI, 1995) from experiments in which the transformation was induced by impact. These data, together with an analysis based on a certain linearization, are used to determine the values of phase boundary velocity and driving force in each impact experiment. The resulting kinetic law which relates these two quantities is displayed in a figure later in the text