Tribological properties of Fe–Ni-based composites with Ni-coated reduced graphene oxide–MoS2

Fe–Ni-based composites with Ni-coated reduced grapheme oxide (RGO)–MoS 2 were fabricated by powder metallurgy technique, and their morphology, phase composition, and tribological properties at different temperatures were investigated systematically. Results showed that Fe–Ni-based composite with Ni-coated RGO–MoS 2 possessed much more uniform and denser microstructure, and higher hardness than that with RGO–MoS 2 . Furthermore, Ni-coated RGO–MoS 2 additive greatly allowed increasing the friction-reducing and wear-resistant properties, due to the reinforcing and lubricating effect new phase (Fe 3 W 3 C, Cr x S 1+ x , etc.) and the improvement on interfacial compatibility between Ni-coated RGO–MoS 2 and Fe–Ni matrix. In particular, as the content of Ni-coated RGO–MoS 2 was 5 wt%, the friction coefficient and wear rate of the corresponding composite was decreased nearly 50% and 75%, respectively. More importantly, Ni-coated RGO–MoS 2 reinforced composite kept excellent tribological properties at elevated temperature. Its friction coefficient decreased firstly with the increased temperature from 25℃ to 400℃, then increased slightly when the temperature increased to 600℃. Besides, the wear rate was only 0.73–0.9 × 10 −4 mm 3 /Nm during the whole temperature range. This suggested that Ni-coated RGO–MoS 2 was a promising additive of metallic-based composites suitable for high-temperature sliding condition.