Surface integrity evolution of WC-10Co-4Cr coating under tangential ultrasonic vibration-assisted grinding

Abstract WC-10Co-4Cr coatings are commonly applied in wear-resistant applications, but their high hardness and brittleness present considerable challenges for precision machining. This study investigated the efficacy of tangential ultrasonic vibration-assisted grinding (TUVAG) in promoting superior surface integrity of WC-10Co-4Cr coatings through a combined theoretical and experimental analysis of its kinematic characteristics. The grinding performance was comprehensively assessed based on grinding forces, surface roughness Ra, surface/subsurface topography, and subsurface microhardness. A reduction is observed in grinding forces with ultrasonic vibration, with the normal force declining by 5.05%-14.04% and the tangential force by 3.04%-17.09%. A significant difference in the grinding force ratio is observed between 20 and 80 m/s grinding speeds. TUVAG effectively decreases surface roughness by 4.09%-17.86%, increases subsurface microhardness, and consequently enhances surface quality. Regardless of whether the material removal mechanism is dominated by ductile deformation or brittle fracture, ultrasonic vibration contributes to reduced surface defects and suppressed crack propagation, thereby improving surface integrity. This research provides a theoretical basis and technical reference for achieving high-quality and high-efficiency machining of WC-10Co-4Cr coatings.