STUDY ON DEFORMATION BEHAVIOUR OF Cu-Al-Zn-Mn-Ni-MARTENSITE.

Based on in-situ observation of deformation by a scanning electron microscope with a tension testing stage, the deformation characteristics and fracture behaviour of the thermoelastic martensite are analysed in comparison with those in single crystals. The reorientation and coalescence of the martensite variants frequently lag behind the cross slip of real plastic deformation due to the constraint of grain boundaries and the variation in orientation thus the completion of coalescence which characterizes the deformation behaviour of martensite in a single crystal is seldom observed. The deformation appears in a more uniform mode in the specimen with grain refinement, which would be an effective way to improve the properties as well as the pseudoelasticity and shape memory effect.