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Frictional behavior of carbide-derived carbon (CDC) coatings on SiC was modified by using MoS 3 as solid lubricants in two forms, i.e. a powder lubricant and a lubricating additive. As the powder lubricant, MoS 3 was unfavorable for the tribological behavior of CDC coatings. Moreover, its friction and wear behaviors were worse than that of MoS 2 . As the lubricating additive, MoS 3 was in-situ prepared within CDC coatings to obtain two kinds of CDC-MoS 3 composites with different microstructures. The CDC-MoS 3 composites showed lower friction than untreated CDC coatings and their tribological behavior was significantly affected by the microstructures. [ABSTRACT FROM AUTHOR]

Carbide-derived carbon (CDC) coatings with dimple (CDC@GSiC coating) and loosely dispersive particles structures (CDC@RBSiC coating) were prepared on two kinds of SiC substrates by using chlorination at 1,000 °C in a 5 vol.% Cl-Ar gas. Microstructural effect makes the two CDC coatings exhibit different frictional behavior in ambient pressure and in vacuum. For the CDC@RBSiC coating, the friction coefficient was from 0.08 to 0.12 at ambient pressure and is sensitive to evacuation from ambient pressure to 10 Pa while it was as high as 0.42 up to a pressure of 10 Pa. Progressive evacuation does not vary the friction coefficient of the CDC@GSiC coating up to 10Pa. The wear of the CDC@GSiC coating was low with a maximum depth of 8 μm and much lower than that of the CDC@RBSiC coating (70 μm). The dimples on the surface and pores in the CDC@GSiC coating are reservoirs for ion liquid (IL), and the IL impregnated CDC@GSiC coating shows very low friction and wear at ambient pressure and in vacuum. [ABSTRACT FROM AUTHOR]

Ti3SiC2/CaF2 composites were prepared by the spark plasma sintering (SPS) process. Both the microstructure of Ti3SiC2/CaF2 and the influence of test temperature on the tribological behavior of the Ti3SiC2/CaF2 composites were investigated. The synergistic effect of friction and oxidation was evaluated by analyzing the worn surface morphology. The results showed that Ti3SiC2/CaF2 were still brittle materials after adding CaF2, which was in agreement with Ti3SiC2. The hardness, relative density, flexural strength and compressive strength of the Ti3SiC2/CaF2 composites were slightly lower than those of Ti3SiC2, and the addition of CaF2 decreased the decomposition temperature of Ti3SiC2 from 1350 to 1300 °C. Simultaneously, as the temperature of the test increased, the friction coefficient of Ti3SiC2/CaF2 showed a downward trend (from 0.81 to 0.34), and its the wear rate was insensitive. [ABSTRACT FROM AUTHOR]