熔石英磨削砂轮截面轮廓分析与优化

摘要

In order to improve the grinding quality of fused silica optics and reduce the depth of subsurface defect (SSD),the experiment of grinding fused silica and theoretical analysis were carried out by parallel diamond grinding wheels with straight edge and circular edge.The stress concentratio non the straight edge of wheel was the main cause of deep defects like continuous white line,whose depth was about 22 μm.To relieve the stress concentration,a combined cross section profile with circular edges was designed.The propounded dressing method was verified by wheel dressing experiment.After grinding using the latter wheel,the deep defect was constrained remarkably,and the depth of SSD was below 2.5 μm.The purpose of low defect grinding of fused silica optics was achieved.%为提高熔石英光学元件磨削加工质量,降低亚表面缺陷层深度,通过实验和理论分析发现,具有平直截面轮廓的平行金刚石砂轮,在加工熔石英光学元件时砂轮边缘位置处会产生加工应力集中,该应力集中直接导致了元件表面产生“连续白线”状深缺陷,其深度达22μm.为抑制砂轮边缘位置加工应力集中现象,设计了“中央平直线+两侧边缘圆弧过渡”的复合式截面轮廓,并提出了相应的修整方法.通过砂轮修整实验,验证了该方法的可行性,磨削元件“连续白线”状深缺陷得到明显改善,亚表面缺陷深度小于2.5 μm,实现熔石英元件的低缺陷磨削加工.