Abstract:The effects of annealing processes, aging processes and cyclic strain on shape memory behaviors of Ti-50.8Ni-0.1Zr alloy were investigated by tensile test, optical microscopy and TEM. The alloys annealed at 350~400 ℃ and 600~700 ℃ present superelasticity (SE), the alloys annealed at 450~550 ℃ present shape memory effect (SME), the alloys aged at 300 ℃ for 1~50 h and at 400 ℃ for 1 h present SE, and the alloys aged at 400 ℃ for 5~50 h and 500 ℃ for 1~50 h present SME. With increasing annealing temperature, the platform stress (σM) of the stress-strain curve in the alloy decreases firstly and then increases, and the minimum 200 MPa obtained in the alloy annealed at 500 ℃; the residual strain (εR) increases firstly and then decreases, and the maximum 2.64% obtained in the alloy annealed at 500 ℃. With increasing aging time, the σM decreases, and the εR is small in the alloy aged at 300 ℃; the σM decreases, and the εR increases firstly and then tends to stable in the alloy aged at 400 ℃ and 500 ℃. With increasing stress-strain cycle number, the superelasticity type alloy transforms from incompletely nonlinear superelasticity to completely nonlinear superelasticity, and the σM and energy dissipation (△W) decrease firstly and then tend to stable; the σM and △W decrease firstly and then tend to stable in shape memory effect type alloy.