Tribological performance of WS2/PAI composite coating reinforced with carbon nanotubes-carbon fiber at high temperatures

The carbon nanotubes (CNTs) were chemically grafted onto carbon fibers (CFs) to prepare a CNTs-CF multiscale reinforcement. The tungsten disulfide/polyamide-imide (WS 2 /PAI) composite coating, with PAI as the binder and WS 2 as the lubricant filler, was prepared. The enhancement mechanism of CNTs-CF on the high-temperature tribological performance of WS 2 /PAI composite coating was analyzed. The addition of CNTs-CF was found to increase the temperature of the 10% mass loss of PAI by 14.2°C, indicating its ability to improve the thermal stability of the coating. The hardness of the CNTs-CF-modified WS 2 /PAI composite coating was measured to be 17.9% higher than that of the WS 2 /PAI substrate. The incorporation of CNTs-CF significantly improved the tribological performance of the WS 2 /PAI composite coating. Particularly at 200°C, the friction coefficient and wear rate of CNTs-CF modified WS 2 /PAI composite coating were only 0.095 and 8.92 × 10 −5 mm 3 /(N·m), respectively, which decreased by about 70.3% and 62.2% compared to the WS 2 /PAI substrate. Further analysis revealed that CNTs-CF is firmly embedded within the WS 2 /PAI composite coating through the synergistic mechanism of mechanical interlocking and molecular adsorption. Furthermore, CNTs-CF formed a stable lubricating film, ensuring the excellent friction and wear performance of the coating. Highlights The CNTs-CF can mitigate the thermal degradation of PAI. The high-temperature wear resistance of the coating was noticeably improved. The problem of CF easily detaching from the coating was resolved. The main components of the transfer film were analyzed.