Surface topography simulation and investigation of thermo-mechanical-chemical coupling damage mechanisms for TiCN-based cermet tool inserts

To accurately predict the surface morphology and reveal the formation mechanism of cutting-edge damage in the grinding of TiCN-based cermet tool inserts, this study proposes a novel predictive simulation model that integrates non-Gaussian grinding wheel topography with multi-grain kinematics analysis. Furthermore, a thermo-mechanical-chemical coupled model is established to describe the cutting-edge damage formation mechanism. Grinding experiments were conducted under industrially relevant parameters, including grinding wheel speed, workpiece rotational speed, grinding depth, to systematically investigate the effects on surface roughness R _a and the qualification rate of the tool inserts. The results reveal that the maximum undeformed chip thickness is the key parameter governing both surface morphology and damage evolution. As the maximum undeformed chip thickness increases from 0.424 µm to 0.812 µm, edge damage evolves from micro-serrations to macro-spalling, with the damage width expanding from 11.32 µm to 30.65 µm. Energy‑dispersive X-ray spectroscopy analysis indicates that elevated grinding temperatures induce the oxidation of the Co/Ni binder phase to CoO/NiO, promoting interface embrittlement and microcrack propagation, which ultimately triggers brittle fracture. Critically, maintaining the maximum undeformed chip thickness below the brittle‑to‑ductile transition threshold is essential to suppress brittle damage and preserve edge integrity. This work provides a theoretical foundation for damage prediction and process optimization during the grinding of hard‑brittle ceramic materials.