摘要
集群磁流变平面抛光加工硬脆材料可以高效率获得纳米/亚纳米级表面粗糙度，其中集群磁流变效应抛光垫对加工表面的作用力（抛光力）是材料去除的关键因素，搭建了集群磁流变平面抛光三向测力平台，对模拟的集群磁流变抛光加工过程抛光力（切向力 Ft和法向力 Fn）进行了系统试验研究。结果表明，2＇单晶硅片试验条件下集群磁流变平面抛光切向力 Ft最大达到32.25 N、法向力Fn最大达到62.35 N、Ft/Fn值为0.46～0.77；对抛光力影响最大的工艺参数是磁场强度和加工间隙，其次是羰基铁粉与磨料质量分数、磁流变液流量、抛光盘转速，工件摆幅与速率影响最小。集群磁流变平面抛光力大小以及Ft/Fn值随着工件材料硬度的增大而增大，具有低正压力高剪切力特征，有利于提高硬脆材料的超光滑平坦化抛光加工效果。
A viscoplastic cluster MR effect pad is formed between the surface of polishing plate and the workpiece. Under the effect of a magnetic field, MR effect pad remove material from the surface being machined, which has been applied to polish a large variety of brittle materials, ranging from optical glasses to hard crystals, to a nanometer surface. Knowledge of forces acting is important to understand the mechanism of material removal for MR effect pad. Three-component dynamometer instrumentation is used to on-line record the normal force and tangential force acting on the workpiece through the MR effect pad. It is found that the maximal tangential forceFt value is 32.25 N and the maximal normal forceFn value is 62.35 N, and the ratio between them is about 0.46-0.77. The most contribution is observed that of the machining gap and magnetic field strength on the forces developed on the workpiece surface, followed by CIPs and abrasives concentration, the fluid flow rate, the polishing plate speed, while the least contribution is noticed by the feed distance and feed rate of workpiece. The forces from the cluster MR effect pad and the ratioFt/Fnincrease with the increase in the hardness of the workpieces. The forces acting on the harder workpieces have the characteristic with low normal pressure and high shear force, and this is beneficial to improve the quality of super-smooth planarization polishing.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2015年第15期190-197,共8页
Journal of Mechanical Engineering
基金
国家自然科学基金(51375097
U1034006)
高等学校博士学科点专项科研基金(20134420110001)资助项目
关键词
磁流变效应抛光垫
法向力
切向力
工艺参数
MR effect pad
normal force
tangential force
machining parameters
