Study on the Friction-Reducing Mechanisms of Surface Texture Cemented Carbide under Dry Sliding

During the dry cutting of difficult-to-machine materials, the cutting tools are subjected to high temperatures and pressures due to the serious friction at the tool-chip interface, which leads to severe tool wear. To improve the tribological properties of the cutting tool surface, this paper investigates the friction-reducing mechanisms of surface texture on YG8 cemented carbide under dry conditions through friction and wear tests. The results show that surface texture effectively reduces the coefficient of friction (CoF) and the wear rate of cemented carbide. Compared with the smooth surface, the average CoF value of parallel micro-groove, perpendicular micro-groove (PE) and hexagonal texture (HE) decreased by 16.5, 24.0 and 29.9%, respectively, and the wear rate decreased by 24.1, 55.1 and 66.0%, respectively. The friction-reducing mechanisms of surface texture change during the different dry sliding stages. In the early stage, the grooves of the textured samples reduce surface wear by accommodating metal debris. In the later stage, the grooves on the PE and HE surfaces are filled with metal debris, which cannot further accommodate metal debris, instead of forming the soft-hard composite surface with lower CoF value and higher wear resistance. The results of FEM show that the formation of the soft-hard composite surface can reduce the maximum principal stress and make the stress distribution more uniform, which proves that the soft-hard composite surface has excellent performance on the other hand.