Characteristics of Ti–Ni–Pd shape memory alloy thin films

Ti–Ni–Pd thin films were deposited by RF magnetron sputtering. Microstructure and phase transformation behaviors were studied by X-ray diffraction (XRD), by transmission electron microscopy and by differential scanning calorimeter (DSC). Also tensile tests and the internal friction characteristics were examined. Annealing at 750 °C followed by subsequent annealing at 450 °C resulted in relatively homogeneous microstructure and uniform martensite/austenite transformation. The results from DSC showed clearly the martensitic transformation upon heating and cooling, the transformation temperatures are 112 °C (M* peak) and 91 °C (M peak), respectively. The transformation characteristics are also found in strain–temperature curves and internal friction–temperature curves. The film had shape memory effect. The frequency had no effect on the modulus, but the internal friction decreased with increasing frequency.