Transformation Heat Study of TiNi and TiNiCu SMA Wire/Nickel Smart Composites

The transformation heat of martensitic transformations in TiNi and TiNiCu wire/nickel composites is studied by differential scanning calorimetry (DSC). Results show that the transformation heat of the first reverse martensitic transformation of prestrain TiNi specimen in a free condition is found to increase quickly with the increasing prestrain level In comparison with this, the transformation heat of the first reverse martensitic transformation of prestrain TiNi specimen with nickel matrix is found to decrease quickly with the increasing prestrain level. However, the transformation heat change trends of TiNiCu and TiNiCu wire/nickel composites are obviously different from that of TiNi and TiNi wire/nickel composites. The reason for these phenomena above is fully explained.