Influence of CrN, TiAlN monolayers and TiAlN/CrN multilayer ceramic films on structural, mechanical and tribological behavior of β-type Ti45Nb alloys

CrN, TiAlN single layers, and CrN/TiAlN multilayer ceramic films were deposited on Ti45Nb substrates by an industrial cathodic arc PVD process. The phase structures, the cross-sectional morphology, adhesion strength, surface hardness, and tribological behavior of the resulting uncoated and coated samples were evaluated in detail. The results showed that the preferred orientation was changed from (200) in CrN and TiAlN single layer films to (111) plane in the TiAlN/CrN multilayer films. The multilayered TiAlN/CrN films had smaller crystallite size than the single CrN and TiAlN films. The multilayer film coated samples exhibited the maximum surface hardness and the best adhesion strength among all samples. In addition, the results of wear tests present that all ceramic coatings showed better tribological properties than uncoated TiNb45 substrate materials and the best performance was observed from multilayer film-coated samples.