Effects of Pre-deformation Annealing on Mechanical Properties of Ti-Based Amorphous Alloys

Ti40Ni40Cu20 amorphous matrix composite plate specimens were fabricated by the levitation suspend melting-water cooled Cu mold process. The specimens were pre-compressed at different degrees with a universal testing machine and then annealed at 150 °C for 30 min. The effects of pre-deformation annealing processes on the microstructure and mechanical properties of Ti40Ni40Cu20 alloy system were studied by a metallographic microscope, X-ray diffraction (XRD) and scanning electron microscope (SEM). The results show the martensitic phase transformation that of the austenite phase under external force occurs. The phase transition induced by the deformation coupled with the annealing release of residual thermal stress plays a role in enhancing both strength and toughness of the amorphous matrix composite. Both martensite phases and austenite phases are increased with the increase with the degrees of pre-deformation increasing, and martensite phases are increased faster. Thus, the yield strength of the composite increases, while the ductility declines. Therefore the controllable yield strength in the pre-compression stage for shaping can be realized.