Effects of Deposition Temperature and Ar Pressure on Phase Structure and Properties of Ti Films

Ti films were deposited at low temperature (166 K) and room temperature (300 K) under different Ar pressures of 0.2-0.8 Pa by arc ion plating (AIP). The phase structure and properties of the Ti films were studied using X-ray diffraction (XRD), atomic force microscope (AFM), microhardness tester and scratch tester. The results show that the Ti films deposited at various deposition conditions had a two-phase nanocomposite structure of hexagonal closed-packed (hcp) ω-Ti and α-Ti phases, and showed an increase in the relative content of ω phase with decreasing deposition temperature and Ar pressure. Thus the Ti films, deposited at lower temperature and Ar pressure, presented a higher microhardness because the ω phase is a hard brittle phase, and a better adhesion with steel substrate. Therefore, the Ti films deposited at lower temperature and Ar pressure were feasible for interlayers between solid lubricating films and steel substrates to improve their adhesion and load carrying capacity.