Scratch and grinding behavior of different cemented carbide grades for cutting inserts

Abstract

Material removal mechanisms and grinding characteristics of brittle materials are commonly analyzed based on their mechanical and tribological properties. However, the distinctly operating conditions between laboratory tests and real processes are commonly neglected, and associations cannot always be made. Within this context and to analyze possible correlations between material properties (mechanical and tribological) and their grindability, different commercial (WC-Co based K10, M10, and P10) and customized (NbC-Ni based) cemented carbide grades applied as cutting tools had their hardness and fracture toughness measured, and were investigated through scratch and grinding experiments. The process forces, specific energy, and surface and edge quality were assessed during grinding, while the apparent coefficient of friction, material removal factor, specific energy, and groove integrity were analyzed during scratching. No clear correlation could be found between the mechanical/tribological properties and grindability, indicating that, from a process point of view, the difficulty associated with grinding of all investigated cemented carbides is similar, despite of different hardness-toughness combinations.