Effect of peak current on the microstructure, mechanical properties and tribological behavior of MoxN coatings deposited by high power impulse magnetron sputtering

The MoxN coatings are deposited by direct current magnetron sputtering (DCMS) and high power impulse magnetron sputtering (HiPIMS). It is found that the MoxN coatings prepared by HiPIMS has a denser microstructure, higher hardness and wear resistance. Besides, the effect of peak current is investigated with respect to the microstructure, mechanical properties and tribological behavior of the coatings. As the peak current increases, the cross-sectional morphology of the coating transforms from featureless to columnar morphology, and the preferred orientation of the coating gradually transfers from (111) to (200). However, the hardness of the coating is not significantly influenced by the peak current. The MoxN coating with a peak current of 260 A owns a low friction coefficient of 0.28, which is better than that of the MoxN coating prepared by DCMS. The MoxN coating with a peak current of 300 A provides excellent wear resistance with the lowest wear rate of 5 × 10−8 mm3/(Nm).