Preparation of Cu-Al-Ni shape memory alloy strips by spray deposition-hot rolling route

The present work describes the preparation of near-full density Cu-Al-Ni shape memory alloy (SMA) strips via a novel processing route consisting of 'spray deposition' of atomised liquid Cu-Al-Ni alloy with a jet of argon gas followed by hot-rolling densification of the deposited preform. The subsequent homogenisation of the hot rolled Cu-Al-Ni strips resulted in complete martensitic structure in the finished strip, consisting of self-accommodated plates of beta(1)' and gamma(1)' martensites. The characteristic transformation temperatures and shape memory effects of Cu-Al-Ni strips were studied. It has been demonstrated that the Cu-Al-Ni SMA strips, prepared in the present work, resulted in relatively finer grain size with better combination of strength and ductility compared to other techniques based on conventional casting method.