Response to applied mechanical load of a multivariant martensitic Cu-Zn-Al-Fe shape memory alloy

A multlvariant martensitic Cu-Zn-Al-Fe Shape Memory Alloy has been analysed by means of tensile loading-unloading tests, X-ray diffraction and scanning electron microscopy. The tensile superelastic curve was correlated with the crystallographic reorientation of the martensite plate variants. The stress plateaus correspond to the reversible formation of (016) variant, up to 20 MPa, accompanied by the increase of the second and third order microstrains that reach a maximum level. The subsequent stress Increase caused an augmentation of almost four times of the average elasticity modulus accompanied by both the reorientation of almost 70 % of the martensite plate variants, which turned into the (009) variant, and by the gradual decrease of the microstrain level.