The thermomechanical properties of shape memory effect and superelasti
city due to the martensitic transformation and the R-phase transformat
ion of TiNi shape memory alloy were investigated experimentally. The t
ransformation line, recovery stress and fatigue property due to both t
ransformations were discussed for cyclic deformation. The thermomechan
ical properties due to the R-phase transformation were excellent for d
eformation with high cycles.