多相复杂系统国家重点实验室知识库

A self-lubricating NiCoCrAIY-Cr2O3-AgMo composite coating was deposited by atmospheric plasma spray technology. Phase composition, microstructure and thermal behavior of this coating were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM) and Thermogravimetric Analysis (TGA) respectively. Tribological tests of this coating were conducted at 500 degrees C with different normal loads and sliding velocities. The results showed that the AgMo-containing composite coating exhibited lower friction coefficients around 0.3 at 10 N normal loads due to the formation of Ag2MoO4. However, Ag2MoO4 could not be formed under lower normal load at the critical temperature of 500 degrees C. Further investigation on the long-term wear behaviors of the coating revealed that the excellent friction reduction and wear resistance performance of the AgMo-containing composite coating at elevated temperatures could be ascribed to a liquid Ag2MoO4 film spreading on the upper surface and a dense oxide protective layer underneath. (C) 2017 Published by Elsevier B.V.