Thermally sprayed alumina and ceria-doped-alumina coatings on AZ91 Mg alloy

Present study deals with the development of ceramic based coatings for Mg alloys using thermal spray technique, where Al2O3 is doped with CeO2. Coatings characteristics and other responses are recorded using Nano-indenter, Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), X-ray Diffraction (XRD) and Tribometer. The tribological behavior is recorded in terms of specific wear rates and coefficient of friction under lubricated reciprocating sliding condition for different loads and speeds. Ceria doped alumina coatings showed improved responses. The elastic modulus and nano-hardness of CeO2 doped alumina coating was 13% and 53% higher than alumina coating, respectively. Under high load and high velocity conditions, ceria doped coating registered 40% reduction in specific wear rate. Also, the ceria doping helped in lowering the coefficient of friction during sliding.