PVD改性RB-SiC反射镜表面缺陷处理方法研究

	PVD改性RB-SiC反射镜表面缺陷处理方法研究
	康健
学位类型	硕士
导师	谢京江
	2014-07
学位授予单位	中国科学院大学
学位专业	光学工程
摘要	随着空间光学的快速发展，为满足空间反射镜高分辨率的要求，反射镜的口径不断的增大，这也就要求制造空间反射镜的材料需要在满足光学性能和机械性能的基础上要尽可能的减轻重量。SiC作为一种新型的空间反射镜材料，在近年来得到了飞速的发展。相对于世界先进水平，我国的SiC反射镜加工尚处于起步阶段，由于加工经验不足，在实际加工中会遇到许多问题。本文针对PVD改性RB-SiC反射镜精抛光阶段出现的表面缺陷的形成机理和处理方法进行了相应的理论分析和工艺实验。本文介绍了现阶段国内外SiC反射镜的加工近况，结合本实验室的实际加工能力，以Preston方程为基础，建立了抛光盘在不同工艺参数下对于改性层中大颗粒结晶的冲击力规律的数学模型。以此模型为基础，针对抛光盘的硬度、抛光磨料的粒度以及抛光盘与工件之间的相对压力和相对速度等工艺参数，设计了相关实验，找出各项参数对于改性层中大颗粒结晶冲击力的影响。根据实验结果结合理论分析，初步确定了各种工艺参数对于PVD改性RB-SiC表面缺陷的影响，并据此建立了精抛光的冲击力模型。通过对各种工艺参数的分析和优化，找到了消除和避免表面缺陷的工艺方法，并找出了实验室工艺条件下避免表面缺陷产生的工艺参数区间，拟合出避免表面缺陷产生的抛光冲击力曲线。通过工艺实验所获得的工艺优化方案，成功完成PVD改性RB-SiC基底反射镜一套，加工过程中无严重表面缺陷产生，加工结果符合设计要求。该研究结果对于以后的PVD改性RB-SiC的精抛光加工，改性后表面缺陷的控制具有指导作用。
其他摘要	With the rapid development of space optics, the spatial mirror aperture constantly increases in order to meet the requirement of high optical resolution. The mirror has to be lightweighted as much as possible while the optical and mechanical properties are maintained. SiC is a kind of new material for special mirrors and developed rapidly in recent years. Compared with some advanced countries, SiC technology is still young in China. Many problems had been encountered due to lacking practical experience. This paper focuses on the surface defects of PVD modified RB-SiC mirror during the finishing stage. The treatment methods are discussed based on the analysis of formation mechanism. The background and recent technical status of SiC mirror at home and abroad are described. The mathematical model of impact on the large crystallization particles in modified layer for different technologic parameters is established based on Preston equation and technical ability of the laboratory. The technologic parameters include hardness of polishing lap, granularity of polishing material, relative pressure and velocity of polishing lap and mirror. It is hoped to find out the influence of the impact force by the parameters acting on the crystallization. The experiments are designed and implemented to prove the mathematical model. The influences of the technologic parameters on the defects of PVD modified RB-SiC mirror are analyzed. Based on the result of the analysis, the impact force model is built up. The approaches to estimate surface defects are established through the optimization of the technologic parameters. Basically decided that the surface defects are due to the large crystalline peeled off by the unreasonable impact force. Based on the experiments and the theoretical analysis, a set of the PVD modified RB-SiC mirrors are finished by the optimization parameters. There is no severe surface defect appeared through the process. The research is helpful mirrors to control the surface defect during the manufacture of PVD modified RB-SiC.
语种	中文
文献类型	学位论文
条目标识符	http://ir.ciomp.ac.cn/handle/181722/41420
专题	中科院长春光机所知识产出
推荐引用方式 GB/T 7714	康健. PVD改性RB-SiC反射镜表面缺陷处理方法研究[D]. 中国科学院大学,2014.

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