Abstract:

A viscoelastic cluster MR-effect polishing pad between the surface of polishing plate and workpiece was formed to ultra-precision polish. Polishing pad had an accommodate-sinking effect on abrasive grains in polishing process. Modeling and mechanism of accommodate-sinking effect on abrasives were investigated. Experiments of polishing K9 glass and single crystal silicon were conducted based on MR fluid with adding large abrasive grains, and the surface roughness and micrograph of  the workpieces being machined were investigated. It is found that polished surface based on the fluid mixed 1.8μm diamond into 0.6μm diamond is better than that based on the fluid of uniform 1.1μm diamond. The surface roughness and micrograph of the workpieces demonstrate that the abrasive of accommodate-sinking effect is prominent and it can reduce or eliminate the machined surface defects caused by non-uniformity of abrasive size.

Key words: magnetorheological(MR)-effect polishing pad, abrasive, accommodate-sinking effect, defect

摘要：

针对集群磁流变抛光加工方法,研究了集群磁流变效应抛光垫对磨粒的“容没”机理。通过建立磨粒“容没”模型,并在磁流变抛光工作液中掺杂大尺寸磨粒对K9光学玻璃与硅片进行抛光加工实验，发现在粒径为0.6μm的磨粒中掺杂粒径为1.8μm的金刚石粉进行抛光后的表面质量优于粒径为1.1μm的磨粒加工的表面质量,且发现随着掺杂磨粒尺寸的增大，加工表面的Ra、Rv值虽有增大,但增长幅度远小于同等状况下游离磨粒加工的增长幅度。研究结果表明:集群磁流变效应抛光垫的磨粒“容没”效应能够使粒径不同的磨粒均匀作用于工件表面,显著减小甚至消除大尺寸磨粒对加工表面造成的损伤。

关键词: 磁流变效应抛光垫, 磨粒, “容没”效应, 表面损伤