Thermal expansion property and anisotropy of columnar-grained Cu71.5Al18.5Mn10 shape memory alloy under pre-deformation

Abstract

Columnar-grained Cu-Al-Mn shape memory alloy (SMA) is a kind of obvious anisotropic structure alloy due to its axial high aspect ratio grain structure and axial strong 〈001〉 orientation texture along the solidification direction (SD). Based on the application potential of non-uniform thermal expansion characteristics owing to the martensite transformation characteristics of alloys, in this paper, the anisotropy of thermal expansion property and the effect of pre-deformation on the anisotropy of columnar-grained Cu71.5Al18.5Mn10 shape memory alloy were investigated. The results show that the alloy has obvious thermal expansion anisotropy in different directions and low thermal expansion behavior at certain temperature range. The regulation from positive thermal expansion to negative thermal expansion is achieved in 0° direction along the SD. Furthermore cold rolled pre-deformation treatment can achieve near-zero thermal expansion property with a temperature range of 155.5 K, undergoing a cold rolling deformation of ~12%.