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Abstract: Investigations in graphene of controlling friction and wear of Ni3Al matrix self-lubricating composites (NMSC) are needed for moving mechanical assemblies. The friction and wear behaviors of NMSC with graphene nanoplatelets (GNPs) against Si3N4 ball are tested using a constant load of 10N and a constant speed of 0.2m/s from room temperature (RT) to 600°C. Tribological test results have revealed that small amounts of GNPs in the NMSC are able to drastically reduce the friction coefficients and wear rates over the effective operating range (RT-400°C). A possible explanation for these results is that the refinement of grains accompanying the slippage of laminated sheets between GNPs could provide a source of the stress dissipation and form the GNP protective layer during sliding process, leading to the reduction of wear rates as well as the friction coefficients. It is concluded that GNPs hold great potential applications as an effective solid lubricant for moderate loads and stress, and can be easily used for the preparation of the self-lubricating composites in the future. [Copyright &y& Elsevier]

Dry sliding tribological tests of Ni3Al matrix self-lubricating composites (NMSC) with addition of 15wt% Ti3SiC2 are undertaken against Si3N4, Al2O3, WC-6Co at 25–800°C. The results show that the tribological properties are strongly dependent on the counterface materials. NMSC against Si3N4 shows the lower friction coefficients (0.31–0.48) and wear rates (0.34–2.1×10−5 mm3 N−1 m−1) from 25 to 800°C, while there is no clear difference in tribological performance of NMSC against Al2O3 or WC-6Co. NMSC against Si3N4 may be the optimal design for the excellently tribological performance. [ABSTRACT FROM AUTHOR]

Abstract: The effect of sliding speed and load on the friction and wear behavior of NiAl–10wt%Ti3SiC2 composites (NAT) at room temperature was investigated through determination of friction coefficients and wear rates in different conditions and analysis of morphologies and compositions of wear debris and worn surfaces of both NAT and Si3N4 ball. The results showed that the friction coefficients decreased and wear rates increased with increase in load, whereas they both decreased with increase in sliding speed. The transition in the wear mode from mild to severe wear was strongly influenced by the sliding speed and load. [Copyright &y& Elsevier]