Grinding mechanics of hard-brittle curved surfaces using micro-structured wheels

Precision grinding with micro-structured grinding wheels can greatly boost the grinding performance of hard-brittle optical components. However, the curvature characteristics of components and the topological structures of grinding wheels bring difficulties to investigating the internal material removal mechanisms. This paper presents the grinding mechanics of hard-brittle curved surfaces using micro-structured wheels. First, an accurate model for the maximum undeformed chip thickness of micro-structured grinding wheels is established. The novel design of micro-structured characteristics can improve the grinding uniformity of curved components. Then, a grinding force prediction model is developed based on the material removal mechanisms. Finally, combining theoretical model with experimental verification, the effects of micro-structured characteristics on grinding force, surface quality and subsurface damage are systematically revealed. The grinding force model achieves reliable predictive accuracy, with an average error of 7.47%. Notably, the variable micro-structured characteristics effectively increase the proportion of ductile material removal and significantly improve the grinding uniformity across component regions with different curvatures, with fluctuation limited to 5.77%. These findings not only provide new insights into the fabrication of micro-structured tools, but also render these tools highly suitable for achieving low-damage, high-stability grinding of curved optical components.