兰州理工大学机构知识库

In order to enhance the stability of the materials and reduce the influence of friction and wear on the material properties in the wide temperature range, Ni60 alloy powder was used as the matrix materials, and the composite materials of nickel-based self-lubrication with different LaF3 contents were prepared by spark plasma sintering (SPS) technology. The wide-temperature tribological properties of composite materials in air environment were tested by HT-1000 high temperature friction and wear tester, GBS-Smart WLI white light interference three-dimensional profiler, SEM, XRD, etc. Results indicate that the prepared nickel-based self-lubricating composites have excellent tribological properties in a wide temperature range. When the content of LaF3 is 6%, the average friction coefficient varies from 0.189 to 0.288 in the temperature range from 200 degrees C to 800 degrees C, the lowest friction coefficient of 0.189 is obtained at 600 degrees C and the average wear rate is on the order of 10(-5) mm(3)/N.m, when the sample exhibits the optimal tribological properties. It is because SrSiO3, SrMoO4, La6MoO12 are formed at a high temperature of the composite materials with the content of 6%, the direct contact of the surface is prevented by the formed salt transfer films and the shear strength of the contact layer is reduced, thereby the stability of the material being improved significantly in a wide temperature range. As the test temperature is increased to 800 degrees C, the friction coefficient of the composite increases slightly due to high temperature oxidations, but remains at a low level of 0.2.