Effects of SPS Sintering Pressure on Microstructure and Tribological Properties of 60NiTi Alloy

60NiTi alloys were fabricated by spark plasma sintering (SPS) at 1000 degrees C. The effects of the sintering pressure on the microstructure, microhardness and tribological properties of 60NiTi alloys were investigated. The phase structures and microstructures of 60NiTi alloys were analyzed by X-ray diffractometer (XRD) and scanning electron microscopy (SEM). The microhardness and tribological properties of 60NiTi alloys at different sintering pressures were evaluated by microhardness tester and ball-on-disk wear tester. The wear morphologies of 60NiTi alloys were analyzed by SEM with energy disperse spectroscopy (EDS) and three-dimensional white light profilometer, and the wear volumes were calculated. The experimental results show that the microstructures of 60NiTi alloy prepared by SPS is uniform and the NiTi phase and Ni3Ti phase are presented in the microstructures. The microhardness of 60NiTi alloys increases with the increase of the sintering pressure. The microhardness of 60NiTi alloys has the biggest HV0.2kg value of 5233.2 MPa at the sintering pressure of 50 MPa. The wear rate and wear scar depth of 60NiTi alloys decrease as the sintering pressure increases. However, when the sintering pressure reaches to 50 MPa, the wear rate and wear scar depth of 60NiTi alloys are the smallest, which are 0.76x10(-5) mm(3)/(N.m) and 15 mu m, respectively. The wear mechanisms of 60NiTi alloys are abrasive wear and adhesive wear.