Polishing of Micro Aspheric Mold Based on Viscoelastic Spherical Small Polishing Tool

doi:10.3901/JME.2023.17.300

Abstract

Abstract: The traditional polishing method for machining small aspheric molds has the problems such as easy tool interference and poor accuracy of surface error compensation. A sub-aperture polishing method using viscoelastic polyester fiber cloth to wrap the spherical small polishing tool is proposed to adapt to the surface shape change of the aspheric mold. Firstly, the compressive deformation rules of the fiber cloth in the polishing process are determined by exploring the relationship between the compression value of the polishing fiber cloth and its irreversible deformation and its viscoelastic stress. A polishing pressure distribution model based on the viscoelastic properties of fiber cloth is proposed, and the linear velocity distribution law is obtained by combining the position and orientation of the polishing tool and the mold, and the tool influence function (TIF) of the small polishing tool is established. Then, it is proved that the polishing method of wrapping a spherical small polishing tool with viscoelastic polyester fiber cloth has a better effect than that of using a rigid spherical small polishing tool through the single point polishing and uniform polishing experiments. Next, the influence of the process parameters such as dwell time, polishing pressure, polishing tool rotation speed, and workpiece axis speed on the material removal depth and surface roughness Ra of the tungsten carbide mold is explored by the ring belt polishing experiments by viscoelastic spherical small polishing tool, and the surface error compensation simulation and experimental verification are carried out on the rotary symmetric aspheric tungsten carbide mold with a diameter of 9.7 mm. Finally, the results show that the simulation results and experimental results of the surface error of the mold are effectively converged, the PV (Peak to valley) values of the mold surface error are improved from 0.208 7 μm to 0.079 9 μm, and the surface roughness at the center is reduced from Ra 20 nm to Ra 10 nm. It is proved that the proposed sub-aperture polishing removal model based on the viscoelastic spherical small polishing tool is effective against the surface precision and surface quality control of micro-diameter aspheric molds.

Key words: spherical small polishing tool, aspheric mold, viscoelastic properties, pressure distribution model, surface accuracy

CLC Number:

TG156

ZHANG Jiarong, WANG Han, ZHUO Shaomu, YAO Honghui, ZHU Xiangyou, MA Shuaijie, ZHAN Daohua. Polishing of Micro Aspheric Mold Based on Viscoelastic Spherical Small Polishing Tool[J]. Journal of Mechanical Engineering, 2023, 59(17): 300-309.

References

[1] 王振忠,施晨淳,张鹏飞,等. 先进光学制造技术最新进展[J]. 机械工程学报,2021,57(8):23-56. WANG Zhenzhong, SHI Chenchun, ZHANG Pengfei, et al. Recent progress of advanced optical manufacturing technology[J]. Journal of Mechanical Engineering,2021,57(8):23-56.
[2] YIN Shaohui,JIA Hongpeng,ZHANG Guanhua,et al. Review of small aspheric glass lens molding technologies[J]. Frontiers of Mechanical Engineering,2017, 12(1):66-76.
[3] 尹韶辉,朱科军,余剑武,等. 小口径非球面玻璃透镜模压成形[J]. 机械工程学报,2012,48(15):182-192. YIN Shaohui, ZHU Kejun, YU Jianwu, et al. Micro aspheric glass lens molding process[J]. Journal of Mechanical Engineering,2012,48(15):182-192.
[4] CHEN Fengjun, YIN Shaohui, HUANG Han, et al. Fabrication of small aspheric moulds using single point inclined axis grinding[J]. Precision Engineering,2015, 39:107-115.
[5] 陈逢军,尹韶辉,范玉峰,等. 一种非球面超精密单点磨削与形状误差补偿技术[J]. 机械工程学报,2010,46(23):186-191. CHEN Fengjun,YIN Shaohui,FAN Yufeng,et al. Ultra-precision single-point grinding technique and profile error compensation method for machining aspheric mould[J]. Journal of Mechanical Engineering,2010,46(23):186-191.
[6] 王永强,尹韶辉,李林升,等. 小口径非球面光学模具斜轴磨削加工试验研究[J]. 南华大学学报,2016(4):49-55. WANG Yongqiang,YIN Shaohui,LI Linsheng,et al. Experimental study on inclined rotational grinding for small aspherical optical mould[J]. Journal of University of South China,2016(4):49-55.
[7] PENG Yunfeng,SHEN Bingyi,WANG Zhenzhong,et al. Review on polishing technology of small-scale aspheric optics[J]. The International Journal of Advanced Manufacturing Technology,2021,115:965-987.
[8] 袁巨龙,吴喆,吕冰海,等. 非球面超精密抛光技术研究现状[J]. 机械工程学报,2012,48(23):167-177. YUAN Julong,WU Zhe,LÜ Binghai,et al. Review on ultra-precision polishing technology of aspheric surface[J]. Journal of Mechanical Engineering,2012,18(23):167-177.
[9] GUO Zongfu,JIN Tan,XIE Guizhi,et al. Approaches enhancing the process accuracy of fluid jet polishing for making ultra-precision optical components[J]. Precision Engineering,2019,56:20-37.
[10] ZHAO Xuechu,MA Liran,XU Xuefeng. Mode transition from adsorption removal to bombardment removal induced by nanoparticle-surface collisions in fluid jet polishing[J]. Friction,2021,9:1127-1137.
[11] DING Jiaoteng,FAN Xuewu,XU Liang,et al. High-precision resin layer polishing of carbon fiber mirror based on optimized ion beam figuring process[J]. Optik.,2020,206:163575.
[12] MI S,TOROS A,GRAZIOSI T,et al. Non-contact polishing of single crystal diamond by ion beam etching[J]. Diamond and Related Materials,2019,92:248-252.
[13] YADAV R D,SINGH A K,ARORA K. Parametric analysis of magnetorheological finishing process for improved performance of gear profile[J]. Journal of Manufacturing Processes,2020,57:254-267.
[14] BEDI T S,KANT R. Comparative performance of magnetorheological external finishing tools using different magnetic structures[J]. Materials Today:Proceedings,2021,41:908-904.
[15] 尹韶辉,徐志强,陈逢军,等. 小口径非球面斜轴磁流变抛光技术[J]. 机械工程学报,2013,49(17):33-38. YIN Shaohui,XU Zhiqiang,CHEN Fengjun,et al. Magneto-rheological polishing technology of small diameter aspherical inclined axis[J]. Journal of Mechanical Engineering,2013,49(17):33-38.
[16] 颜晓强,王晗,张嘉荣,等. 小口径非球面小球头接触式抛光及磁流变抛光组合加工[J]. 表面技术, 2021,51(7):1-15. YAN Xiaoqiang,WANG Han,ZHANG Jiarong,et al. Combined process of small ball-end contact polishing and magnetorheological polishing for small aspheric surface[J]. Surface Technology,2021,51(7):1-15.
[17] CHENG Haobo,DONG Zhichao,YE Xu,et al. Subsurface damages of fused silica developed during deterministic small tool polishing[J]. Optics Express,2014,22(15):18588.
[18] DONG Zhichao,CHENG Haobo,TAM H Y. Modified subaperture tool influence functions of a flat-pitch polisher with reverse-calculated material removal rate[J]. Appl Optics,2014,53(11):2455-2464.
[19] ASPDEN R,MCDONOUGH R,NITCHIE F R. Computer assisted optical surfacing[J]. Applied Optics,1972,11(12) 2739-47[J].
[20] JONES R A. Computer controlled optical surfacing with orbital tool motion[J]. Proceedings of SPIE-The International Society for Optical Engineering,1986,550:87-95.
[21] 吴清飞,任志英,高诚辉,等. 计算机控制光学表面成形技术的驻留时间算法[J]. 光学仪器,2017,39(4):40-48. WU Qingfei,REN Zhiying,GAO Chenghui,et al. Dwell time algorithm for computer-controlled optical surface technology[J]. Optical Instruments,2017,39(4):40-48.
[22] CAO Z,CHEUNG C F. Multi-scale modeling and simulation of material removal characteristics in computer-controlled bonnet polishing[J]. International Journal of Mechanical Sciences,2016,106:147-156.
[23] CAO Z,CHEUNG C F,HO L T,et al. Theoretical and experimental investigation of surface generation in swing precess bonnet polishing of complex three-dimensional structured surfaces[J]. Precision Engineering,2017,50:361-371.
[24] LIN Bin,LI Kailong,CAO Zhongchen,et al. Modeling of pad surface topography and material removal characteristics for computer-controlled optical surfacing process[J]. Journal of Materials Processing Technology,2019,265:210-218.
[25] ASPDEN R,MCDONOUGH R. NITCHIE F. Computer assisted optical surfacing[J]. Applied Optics,1972,11(12):2739-2747.
[26] ZHANG Jiarong,WANG Han,ZHU Xiangyou,et al. Surface quality control strategy of aspherical mold based on screw feed polishing of small polishing tool[J]. Materials,2022,15(14):4848.