Xu, J.Mao, X.Xie, Z.Munroe, P.2013-07-152013-07-152013Journal of Physics D: Applied Physics, 2013; 46(6):1-160022-37271361-6463http://hdl.handle.net/2440/78764In this study, novel nanocrystalline molybdenum silicide coatings with differing Al contents were deposited on a commercial titanium substrate using a double-cathode glow discharge apparatus. Their microstructures were characterized by x-ray diffraction, scanning electron microscopy (SEM) and transmission electron microscopy. These coatings mainly consisted of MoSi₂ and Mo₅Si₃ phases; the ratio of Mo₅Si₃ to MoSi₂ gradually increased from the surface towards the interior of coatings, forming a graded structure. With the increase in Al content, the hardness and elastic modulus of the coatings slightly decreased, but the ratios of H/E and 1/E²H, as well as damage tolerance, increased. Furthermore, these newly developed coatings showed excellent wear resistance; their specific wear rates were not only considerably lower than that of the monolithic MoSi₂ coating, but also decreased with increasing Al content. The plan and cross-sectional views of the worn surfaces and wear debris were analysed using SEM and energy dispersive x-ray spectroscopy. The relationships between coating structure, mechanical property and wear mechanism were then clarified, which will help in designing hard, tough and wear-resistant coatings for applications involving severe loading conditions.en© 2013 IOP Publishing Ltd.Surfaces, interfaces and thin filmsCondensed matter: structural, mechanical & thermalNanoscale science and low-D systemsJournal article002012567410.1088/0022-3727/46/6/0653040003140935000162-s2.0-8487384697121147