Internal friction peak associated with the interface motion in the martensitic transformation of CuAlNiMnTi shape memory alloy

Abstract

Two internal friction peaks were observed in a CuAlNiMnTi polycrystalline shape memory alloy during the martensitic transformation through an incomplete phase transformation method, of which the high-temperature peak PH is discussed in the present study. It has been found that the PH peak is discernible only at relatively low frequencies and its maximum corresponds to the inflection point of the relative dynamic modulus rather than its minimum, i.e., this peak is related to a process without soft mode effect. An internal friction model is proposed to describe the PH peak based on the theory of phase nucleation and growth in the thermoelastic martensitic transformation and is verified by the experimental results. © 2007 American Institute of Physics.