Annealing effect on martensitic transformation of severely cold-rolled Ti50Ni40Cu10 shape memory alloy

The annealing effect on the recovery of B2 → B19 and B19 → B19′ transformations of 40% cold-rolled Ti50Ni40Cu10 is studied by the differential scanning calorimetry (DSC) and dynamic mechanical analyzer (DMA) tests. The DSC test is only sensitive for measuring the recovery of B2 → B19 transformation, while the DMA test is suitable for both transformations. The change of internal friction values of these two transformations affected by annealing is due mainly to the difference in the rate of change of the transformation volume between them, which is related to their different recovery behaviors and microstructures.