Study On Preparation And Tribological Behavior Of MAX Phase

The ternary carbides with hexagonal structure, known as MAX phases (where n=1,2,3......, M is an early transition metal, A is an IIIA or IVA element, and X is C or N, abbreviated as MAX), have aroused researchers’more and more interest because of their excellent mechanical, thermal, electrical and chemical properties. MAX ternary compound has been successfully developed by various techniques, such as chemical vapor deposition (CVD), reactive hot-pressing (HP), hot-isostatic pressing (HIP), pulse discharge sintering (PDS), spark plasma sintering (SPS), self-propagating high-temperature synthesis (SHS), and mechanical alloying (MA).Through delamination of lamellar graphite to preparation two-dimensional graphene, study found it has excellent anti-wear anti-friction effect, can be used as additive in lubricating oil. By delamination of layered MAX compounds can also to prepared two-dimensional graphene structure materials, HF selective etching off Al atoms of Ti3AlC2, can fabricated two-dimensional structure Ti3C2, has a broad application prospect, the morphology, structure evolution and mechanism of different MAX phase in HF solution needs further research.Ternary compound Ti3SiC2, Ti3AlC2and Cr2AlC were synthesized by pressureless sintering the powder mixture of Ti, Si, Cr, Al and graphite. The synthesis mechanism and reaction path for the synthesis of MAX phases were presented through thermodynamic test and phase analysis. The effect of the raw materials, ratio of raw materials, material composition and sintering temperature, on the synthesis, phase composition and microstructure of as-synthesized materials were investigated. The corrosion behavior of Ti3AlC2, and O2AIC in hydrofluoric acid solution at room temperature was studied, combining with the composition and microstructure characteristics of the corrosion products, the influence of HF concentration, and reaction time on corrosion products was analyzed. The phase and morphology evolution of Ti3SiC2, Ti3AlC2and Cr2AIC in hydrofluoric acid under solvothermal conditions were studied, the influence of reaction temperature and time on the final product were also discussed. The tribological performance of as-synthesized MAX phase and HF corrosion product as lubricating oil additive was studied.