Mechanical properties of sputtered TiNiCu shape memory alloy thin films

5 mum thick TiNiCu films were prepared by co-sputtering of a TiNi target and a Cu target. The deposited film had fine grain sizes of about 300 to 400 nm and fully martensitic structure at room temperature. Curvature measurement clearly revealed martensitic transformation of TiNiCu films upon heating and cooling. The stress-strain curves of the deposited films were measured using a micro-tensile tester equipped with a heating and cooling system. The film possessed sufficient ductility and strength for practical applications.