非球面模芯的数控超声波辅助抛光基础研究

项目名称： 非球面模芯的数控超声波辅助抛光基础研究

项目编号： No.60808021

项目类型： 青年科学基金项目

立项/批准年度： 2009

项目学科： 轻工业、手工业

项目作者： 黄启泰

作者单位： 苏州大学

项目金额： 20万元

中文摘要： 本项目基于小口径或微小口径低熔点玻璃模压技术使用的硬质合金模芯的高精度非球面面形修抛需求而提出。研究中创新性地提出非接触式超声波抛光，建立数学理论模型，利用压痕断裂力学相关理论和惠更斯原理计算出去除函数为高斯型分布，并通过单点抛光实验验证了模型和理论计算的正确性。声场的有限元分析表明选择不同直径的振子和抛光间隔可以改变去除函数的形状。通过工艺实验研究了抛光过程中各种工艺参数对材料去除量和表面光洁度的影响，最终获得Ra7.4nm的表面光洁度。研究了适用于非接触式超声波抛光去除函数的时间驻留函数计算方法，将二维反卷积计算简化为一维反卷积计算。研究中组建了数控系统，利用Zernike多项式拟合加工路径上的误差分布，根据单点去除函数计算驻留时间，并对口径30mm碳化钨平面实验工件进行面形修抛，最终将PV 2.631λ30340;球面度误差收敛到PV 0.967λ12290;研究表明非接触式超声波抛光能够获得高斯型分布的去除函数，通过适当的工艺参数可以获得光学级别的表面粗糙度，适当的控制方法可以使得表面误差得到有效的收敛。本项目所展开的研究尚属于基础理论及方法层面，非接触式超声波抛光具有进一步深入研究的意义和价值。

中文关键词： 超声波抛光；非接触；数控；模芯；非球面

英文摘要： This project was put forward based on the requirement of high precision polishing of the small or micro diameter aspheric molding die, which is applied in the low temperature glass molding technology。 Non-contact ultrasonic polishing method was innovatted in this project. Theoretical model was set up and the single point remove function expression was deduced from the indentation fracture mechanics and Huygens' principle. Single point polishing experiments was also proceeded, validity of the model and mathmatical expression was approved. FEA of the sound field indicates that different tool diameter and polishing gap can achieve different removeal function shape. Process parameter influence on removeal efficency and surface roughness was researched through polishing experiments, finally, the surface roughness achieved Ra 7.4 nm. The dwell function calculation method fits to non-contact ultrasonic polishing removal founction was researched, two-dimension deconverlution calculation can be simplified to one-dimension deconerlution calculation, solution procedure of the dwell funtion come to be easy. A numeric control system was established in this research. Zernike polynomial was used to fit the surface error distuributed on polishing route and the dwell time was calculated according to the single point remove function. A Φmm WC flat part was polished in the process of experiment, the surface error was finally astringed from PV 2.631λo PV 0.967λThis research indicats that non-contact ultrasonic polishing can obtain Gaussian shaped remove function and optical class surface roughness with correct process parameters, through proper unmeric control method the surface error can be effectively reduced. This project is only relate to basic theory and technic, a in-depth study on non-contact ultrasonic polishing is necessary and significative.

英文关键词： ultrasonic polishing; non-contact; numeric control;molding die; aspheric