High temperature tribological properties of Fe-Mo-Ni-Cu-Graphite self-lubricating guide sliding plates

Abstract

High-temperature self-lubricating Fe-Mo-Ni-Cu-graphite materials with varying copper contents were prepared by powder metallurgy technology. The microstructure and wear surface of the sintered alloy were observed and analyzed using optical microscopy and scanning electron microscopy. The focus was on discussion of the influence of copper content on the tribological properties of the iron-based material. The results indicate that the friction coefficient and wear rate of the sintered material against a 40Cr steel disc show a decreasing trend after friction with an increase in copper content. Particularly, at a copper content of 15%, the friction coefficient is lowest at both room temperature and 500 °C, exhibiting the best wear resistance. The wear rate is in the order of 10–7 cm3/N•m, indicating mild wear. The predominant wear mechanism for both the material and the counterpart disc is adhesive wear. During friction, the formation of a black-brown lubricating composite film composed of Fe2O3, graphite, Fe2O3 • Fe3O4, CuO, and Fe3O4 on the material’s surface plays a crucial role in providing excellent high-temperature anti-friction properties.