A comparative study on tribological behavior of TiN and TiAlN coatings prepared by arc ion plating technique

TiN and TiAlN coatings were deposited onto AISI D2 steel substrates by an arc ion plating (AIP) technique. These coatings were comparatively studied on their tribological behaviors. For this study, the dry sliding wear experiments were conducted on TiN and TiAlN-coated steel discs at two different contact loads, 1 N and 5 N, and three different sliding speeds, 0.1, 0.3, 0.5 m/s, against the steel and alumina ball using a conventional ball-on-disc sliding wear apparatus. It was found that the adhesive wear behavior was dominant between both coating layers and steel, while the abrasive wear behavior was prevailed in the case of the alumina ball. The friction coefficient of TiAlN coatings became lower than that of TiN coatings at high sliding speed although it was higher at low speed. Similar trends were observed regardless of counterpart materials and applying load in this work. This suggested that TiAlN coatings may be more advantageous than TiN coatings for high speed machining with respect to machining efficiency and to excellent resistance to high temperature oxidation.