基于形性控制的大口径离轴非球面高精度磨削(特邀)  

High precision grinding of large-aperture off-axis aspheric mirror with contour-performance controlling methodology(invited)

作　　者：孙国燕[1,2] 吉霞斌 丁蛟腾 张继弓[1] 成航 Sun Guoyan;Ji Xiabin;Ding Jiaoteng;Zhang Jigong;Cheng Hang(Xi’an Institute of Optics and Precision Mechanics,Chinese Academy of Sciences,Xi’an 710119,China;College of Artificial Intelligence,National University of Defense Technology,Changsha 410003,China)

机构地区：[1]中国科学院西安光学精密机械研究所,陕西西安710119 [2]国防科技大学智能科学学院,湖南长沙410003

出　　处：《红外与激光工程》2023年第9期13-22,共10页Infrared and Laser Engineering

基　　金：国家自然科学基金项目(52105493);陕西省自然科学基础研究计划项目(2023-JC-QN-0713);湖南省自然科学基金项目(2023JJ40670);中国科学院青年创新促进会项目(2023423);中国博士后科学基金项目(4139ZRY4)。

摘　　要：大口径离轴非球面光学元件的应用需求呈大幅增长趋势,如空间/地基大口径望远镜、航空光电和地面跟踪瞄准装置等。同时,日益增大的元件口径和越来越短的加工周期使得高效高精度制造工艺成为大口径离轴非球面光学元件加工的核心问题。精密磨削作为大口径离轴非球面元件的材料高效去除工序,磨削面形精度(Peak-Valley,PV)和损伤层深度直接决定了后续的抛光难度与周期。因此,开展了大口径离轴非球面光学镜面的控形控性高精度磨削研究,即提升大口径离轴非球面光学元件的磨削面形精度的同时降低磨削损伤深度,实现二者在数值上的协同逼近。在控形方面,确立了机床结构方面影响低频面形形状与精度的主要影响因素,探究了A轴零位误差、Y轴对中误差、砂轮形状尺寸误差、磨削方法路径和Z轴面形补偿等因素对面形精度的影响规律以实现工艺参数的协同控制与精度优化。在控性方面,获得了磨削损伤深度随磨削参数的变化规律并建立了磨削损伤深度与磨削表面粗糙度的映射关系,提出针对大口径离轴非球面磨削亚表层损伤抑制策略。对640 mm口径离轴非球面镜进行形性控制磨削实验后,面形精度达到3μm,表面粗糙度Ra小于24 nm,Rz小于0.2μm,依照表面粗糙度与亚表面损伤层深度映射关系,亚表面损伤层深度5μm左右,逼近面型精度。经验证后续抛光周期大幅缩短,对大口径光学元件的高效高精度加工具有重要参考价值。Objective Large Aperture Off-axis Aspherical Optical Elements(LAOAOE)have been increasingly demanded,such as space/ground-based large aperture telescopes,aerial optoelectronics or ground tracking&sighting instruments.Moreover,the requirements for the larger aperture and shorter processing cycle make it be the core problem to manufacture the large aperture off-axis aspheric optical elements with the highly efficient and highprecision manufacturing.For instance,the processing cycle for the LAOAOE with the diameter of 1 meter is required to be 2-3 months.As the highly efficient removal process for the LAOAOE,surface form accuracy and damage depth of precision grinding having directly determined the processing difficulty and processing cycle of the subsequent polishing processing.Therefore,the high precision grinding process of shape-performance control for LAOAOE are investigated in this paper.In other words,it is required to improve the surface form accuracy and reduce the depth of grinding damage,simultaneously.The numerical collaborative approximation of both items is needed to be achieved in the end.Methods In terms of the surface form control,it was identified the main factors for the machine tool structure,which affect the surface form accuracy of low-frequency surfaces.To achieve collaborative control and accuracy optimization of process parameters,the investigations were conducted to explore the influence laws between the surface shape accuracy and the A-axis zero error,Y-axis alignment error,shape and size error of grinding wheel,grinding wheel path,Z-axis surface compensation and so on.For the performance control,the influence laws between the grinding damage depth and grinding parameters were obtained,and the mapping relationship between the grinding damage depth and grinding surface roughness were established.The suppression strategy of the subsurface damage strategies for LAOAOE was proposed in the end.Results and Discussions Firstly,the form accuracy(PV)of the grinding surface was significantly affecte

关 键 词：精密磨削 形性精度 面形精度 亚表层损伤 离轴非球面 

分 类 号：TH162[机械工程—机械制造及自动化]