超声振动辅助抛光BK7过程中聚氨酯抛光垫磨损行为

抛光光学玻璃等硬脆材料时常选用聚氨酯抛光垫，其微观形貌和磨损直接影响抛光精度和效率.本文对不同抛光时长下聚氨酯抛光垫微观形貌和磨损行为及其对材料去除率和表面粗糙度的影响进行了实验研究.结果表明：当主轴转速为8 000 r/min,进给速度为0.015 0 mm/s,轴向超声振幅为5μm时，材料去除率和表面粗糙度分别为0.977μm/min和153.67 nm.聚氨酯抛光垫在30 min内磨损量较小，随着抛光时长的增加，抛光垫表面孔隙逐渐被磨粒和玻璃碎屑填充，破坏抛光垫表面的疏松多孔结构，导致抛光垫表面硬化，失去弹性.同时，侵入抛光垫表面的磨粒会阻止抛光接触区域内的磨粒更新，导致抛光质量降低.

Wear Behavior of Polyurethane Polishing Pads Used in BK7 Ultrasonic Vibration-Assisted Polishing

Polyurethane polishing pads are often used for polishing hard and brittle materials such as optical glass. The morphology and the wear of polishing pads directly influence the polishing accuracy and efficiency. Experimental studies were conducted on the micro-morphology and wear behavior of polyurethane polishing pads during different polishing time and their effects on material removal rate and surface roughness were analyzed. The results showed that the material removal rate and surface roughness are 0.977μm/min and 153.67nm respectively when the spindle speed is 8000r/min， the feed speed is 0.0150mm/s and the axial ultrasonic amplitude is 5μm. Polyurethane polishing pads have relatively little wear in the first 30 min， the surface of the polishing pads is filled with abrasive particles and optical glass debris， as the polishing time increases， damaging the porous structure of polishing pads. The surface of the polishing pads gradually hardens and loses its elasticity. Meanwhile， the abrasive particles and the debris invading the surface of the polishing pads will prevent the renewal of the abrasive particles in the contact area during the polishing， resulting in a reduction in the polishing quality.