Effect of caliber rolling on microstructures and properties of an inoculated Cu-Al-Ni shape memory alloy

With the aim of property enhancement, the grains in a Cu-Al-Ni shape memory alloy (SMA) were successfully refined by adding Al-La-B inoculant. In order to further optimize the microstructure, the inoculated Cu-Al-Ni SMA was then subjected to caliber rolling. It was found that the grains were further significantly refined after caliber rolling, but there was & alpha; phase precipitation. After quenching treatment, the & alpha; phase disappeared, whereas the grain size slightly increased. The changes of properties with the increase of rolling reduction were investigated. It was found that the tensile strength increased, whereas the elongation increased first and then decreased. After quenching treatment, the tensile strength and elongation increased monotonously. The internal friction (IF) peak arising from the reverse martensitic transformation (MT) decreased, and the peak position shifted towards the high temperature side. After quenching treatment, the IF peak increased monotonously, whereas the peak position remained nearly unchanged. Correlated mechanisms were discussed.