Two way shape memory loss in Cu---Zn---Al alloy

Investigation is carried out to understand the reasons behind the degradation of two way shape memory effect in Cu---Zn---Al alloy which exhibits a complete loss in its two way memory effect after a finite number of transformation cycles. It is observed that the two-way memory loss is attributable to a chemical effect viz. the precipitation of intermetallics at the martensite plate boundaries. Since repetitive thermal cycling is related to some kind of ageing effects, the present investigation also includes the study on the ageing behaviour of the alloys. The ageing effects are finally co-related with the observed two-way shape memory loss to describe the transformation fatigue found in the Cu---Zn---Al alloy.