动态磁场集群磁流变抛光加工机理及试验研究

摘要

The machining mechanism of cluster magnetorheological plane finishing and the action mechanism of dynamic magnetic fields were analyzed.The magnetorheological polishing experiments of dynamic magnetic field on silicon substrate were carried out.Results show that the dynamic magnetic field can make the distorted polishing pad self-repair in time,and that the abrasives have frequent dynamic behavior.It overcomes the shortcomings of distorted pads repairing and abrasive agglomeration under the static magnetic field.The material removal process is stable and the polishing effect is better.Under the dynamic magnetic fields,different polishing methods make big different effect on the polishing results.In multi workpieces synchronous polishing,the high speed self rotation of the large size tool head makes the workpieces have higher line speed,and the abrasives has a stronger effect on the surface defect removal of the mono crystalline silicon substrate.After 5 h polishing,the surface of the silicon wafer is super smooth,and its roughness Ra is reduced from 0.48 μm to 3.3 nm.%基于动态磁场集群磁流变平面抛光的加工机理以及动态磁场作用机理,对单晶硅基片进行动态磁场集群磁流变抛光试验研究.结果表明:动态磁场能使畸变的抛光垫实时自修复,磨料具有频繁的动态行为,克服了静态磁场作用下抛光垫变形难恢复且磨料堆聚的缺点,使材料去除过程稳定,抛光效果较好;在动态磁场作用下,不同抛光方式的加工效果也不同;在多工件同步抛光中,大尺寸的工具头高速自转使工件表面有更高的线速度,磨料对单晶硅表面缺陷去除作用更强.经过5h抛光,硅片表面粗糙度Ra由0.48 μm下降到3.3 nm,获得超光滑表面.