Trade-off between surface quality and integrity in grinding of WC–12Co coatings: role of abrasive characteristics and process parameters

Abstract

This study investigates the grinding performance of WC–12Co plasma-sprayed coatings on Ti17 alloy, focusing on the combined effects of abrasive characteristics and process parameters on surface integrity. To achieve this, surface roughness, hardness, and microstructural evolution were systematically evaluated under varying abrasive grain size, concentration, spindle speed, and feed rate. The experimental results demonstrate that increasing abrasive concentration significantly improves surface finish while enhancing surface hardness due to intensified plastic deformation and strain hardening; however, it also promotes microcrack formation, indicating a trade-off between quality and integrity. Furthermore, spindle speed strongly influences surface morphology; while hardness values plateau beyond a critical speed, higher speeds lead to increased microcrack formation, which—based on surface morphological evidence—indicates the dominating role of thermo-mechanical loading during high-speed contact, though direct in-situ thermal measurements were not recorded. At elevated feed rates, a transition in the material removal mechanism from plastic deformation to brittle fracture and material pull-out causes severe surface degradation. In conclusion, these findings indicate that surface integrity in the grinding of WC–12Co coatings cannot be adequately assessed based solely on roughness or hardness, but is governed by the complex interplay between mechanical loading, thermal effects, and material removal mechanisms.