基于压痕断裂力学理论, 建立了工件表面粗糙度与亚表层损伤深度的理论关系模型, 用于预测磨削加工脆性光学材料引起的亚表层损伤深度。利用磁流变角度抛光技术检测了不同磨削加工工艺条件下亚表层的损伤深度, 验证了理论模型的正确性。分析了加工工艺参数对工件表面粗糙度及亚表层损伤深度的影响规律, 提出了提高材料去除率的磨削加工工艺方案。分析结果表明：脆性材料工件的亚表层损伤深度与工件的表面粗糙度呈非线性单调递增关系。工件亚表层损伤深度及工件表面粗糙度均随着切削深度和进给速度的增加而增加, 随着主轴转速的增加而减小。对比实验结果与理论模型预测结果表明, 提出的模型可以准确、无损伤地的预测磨削加工引起的工件亚表层损伤深度。

On the basis of indentation fracture mechanics, a theoretical model was developed to evaluate the relationship between surface roughnesses (SRs) and Subsurface Damage Depths (SSDs) of brittle optical materials and to predict their grinding induced SSDs. For validating the feasibility of this method, the SSDs generated with various process parameters were measured by Magnetorheological Finishing (MRF) wedge technique. The influences of processing parameters on the SRs and SSDs were investigated, and a process strategy was also proposed to improve the material removal rate. The prediction results of this theoretical model show that the SSDs are nonlinear monotone increasing with the square of SR values during grinding processes. The SSDs and SRs increase with the increasing of cutting depth and feed rate, while reduce with the increasing of spindle speed. The measurement results of SSDs are consistent with the prediction values of the model, which demonstrates the feasibility of utilizing this model to accurately and non-destructively predict the SSDs.