Pseudoelastic Hysteresis in Martensitic Reorientation of Cu-Zn-AI Polycrystalline Shape Memory Alloys

The stress-induced martensitic reorientation of two kinds of Cu-Zn-Al polycrystalline shape memory alloys were studied through experiment. Special attention was paid to the deformation behavior of these polycrystals during the reorientation. Experimental result indicates that for the two materials after reorientation the deformation is pseudoelastic as long as applied stress is smaller than the prestress that induced the reorientation. Detailed research on the pseudoelastic hysteresis was performed. The experimental phenomena are very similar to that of the pseudoelasticity of shape memory alloys due to the forward and reverse martensitic transformations at high temperature.