Tribological properties of (Ti,Al)N coatings deposited at different bias voltages using the cathodic arc technique

A study was carried out to see the effect of substrate bias voltage on various tribological properties of (Ti,ADN films deposited using the arc-PVD technique. Films were deposited at substrate biases of -30, -50, -100, -300 and -500 V. It has been found that the Al at.% decreases with an increase in bias voltage. The wear rate measured using a calo-wear test is at a minimum for the films deposited at -100 V bias voltage. Lattice strain and microhardness show a maxima at -100 V. It is observed that the number of macro particles on the surface increases with bias voltage for -30 and -50 V and decreases after -100 V. The Glancing-angle XRD shows the presence of the h-(Ti,Al)N phase at lower bias voltages. The color varies from bluish black (L = 46.2, a* = -0.13, b* = -3.06) to brownish black (L = 43.84, a* = 2.39, b* = -1.53) as the bias voltage is increased. Oxidation and corrosion properties show marginal change with bias voltage. (C) 2001 Elsevier Science B.V. All rights reserved.