Effect of MoS₂−Ag−V₂O₅ on friction and wear properties of nickel-based composites

The nickel-based self-lubricating composites added with the different solid lubrications (MoS₂, Ag, and V₂O₅) were prepared by powder metallurgy sintering. The friction and wear properties of the nickel-based composites were investigated between room temperature and 600 ℃. The phase composition and the wear surface micromorphology were analyzed by X-ray diffraction (XRD), scanning electron microscope (SEM), and Raman spectroscopy. The results indicate that, the friction coefficients of the nickel-based self-lubricating composites increase firstly and then decrease with the temperature increasing. At room temperature, the friction coefficients of the composites decrease with the increase of Ag content; at 600 ℃, the friction coefficients and wear rates of the composites decrease with the increase of V₂O₅ content. The composites mainly reduce the friction and wear by MoS₂ and Ag at medium and low temperatures; a new lubricating phase of silver molybdates is formed in the friction chemical reaction of the composites at the high temperature, and the lubrication mechanism is the synergistic lubrication effect of silver molybdate and V₂O₅ at high temperature.