内循环式非牛顿流体抛光单晶硅的仿真与试验研究

Simulation and Experimental Study on Internal Circulation Non-newton Fluid Polishing of Single Crystal Silicon

为了提高磨料流抛光的效率与应用范围,提出内循环式非牛顿流体抛光方法对传统磨料流加工方式和使用的磨料进行改进。利用计算流体动力学软件对抛光区域的仿真,研究了流道中抛光流体的速度与压力的分布规律和流道槽深与入口速度对于壁面剪切应力的影响。通过单因素试验,研究了磨粒的粒径、质量分数和流道槽深对工件材料去除率和表面粗糙度的影响,并将入口处压力的试验结果与仿真结果对比。结果表明:抛光盘入口处压力仿真结果与试验结果相对误差不超过6%,验证了仿真的可靠性;材料去除率最高可达0.193μm/min,表面粗糙度由280nm降至37nm,证明了内循环式非牛顿流体抛光技术的可行性。

In order to improve the efficiency and application range of abrasive flow polishing,the abrasive and processing methods of abrasive flow machining are improved,and the non-newton fluid polishing of internal circulation is obtained.Using the computational fluid dynamics software to simulate the polishing area,the distribution of the velocity and pressure of the polishing fluid in the flow channel and the effect of the channel depth and inlet velocity on the wall shear stress are studied.The pressure of the simulation at the entrance of the polishing disk is compared with that of the experiment and the influence of the abrasive grain mass fraction,the abrasive particle size and the channel depth on the material removal rate and the surface roughness of the workpiece are studied by single factor experiment.The results show that the relative error between the pressures of the simulation and the experiment at the entrance of the polishing disc does not exceed 6%,which verifies the reliability of the simulation.The maximum material removal rate is 0.193μm/min and the surface roughness is reduced from 280nm to 37nm,which demonstrates the feasibility of internal circulation non-newton fluid polishing.