光学硬脆材料固结磨料研磨中的亚表面损伤预测

摘要

The correct prediction of subsurface damage (SSD) depth in lapping is an important basis for setting processing parameters.According to the lapping features of fixed abrasive,two typical optical hard-brittle materials (MgAl spinel and quartz glass) were selected to establish their respective two-dimensional discrete element models by using the discrete element method (DEM) and to analyze the impact on SSD (crack) depth of optical hard-brittle materials by above processing parameters.After that,an angle polishing method was used to measure the SSD depth of lapped MgAl spinel and quartz glass and to have it verified by experiment.The results show that when applying fixed abrasive for lapping,the abrasive particle size will have a significant impact on the SSDs of optical hard-brittle materials,which means under same lapping processing,the greater the abrasive particle size is,the deeper of SSD and the denser the micro cracks will be.The comparison between experimental results and DEM simulation results indicates that DEM is able to make quick and effective prediction on SSD depth of optical hard-brittle materials and to provide reference and guidance for subsequent lapping and polishing processing.%研磨过程中亚表面损伤层深度的正确预测是研磨工艺参数制定的重要依据.针对固结磨料的研磨特点,选择两种典型光学硬脆材料(镁铝尖晶石和石英玻璃),采用离散元仿真技术,分别建立了两种材料的二维离散元模型,分析了工艺参数对光学硬脆材料亚表面损伤(裂纹)层深度的影响.而后,采用角度抛光法测量了镁铝尖晶石和石英玻璃的亚表面损伤层深度,进行了实验验证.结果表明:采用固结磨料研磨时,磨粒粒径对光学硬脆材料亚表面损伤的影响相当显著,在相同研磨工艺条件下,随着磨粒粒径的增大,亚表面损伤层深度和微裂纹密集程度明显增加.离散元仿真结果与实验结果的对比表明:采用离散元技术可以对光学硬脆材料的亚表面损伤深度进行快速有效的预测,从而为后续的研磨抛光工艺提供参考与指导.