化学气相沉积碳化硅平面反射镜的高精度超光滑加工  

High-precision and Super-smooth Fabrication of CVD SiC Flat Reflecting Mirror

作　　者：康念辉[1] 李圣怡[1] 郑子文[1] 戴一帆[1] 

机构地区：[1]国防科学技术大学,长沙410073

出　　处：《中国机械工程》2009年第1期69-73,共5页China Mechanical Engineering

基　　金：国家自然科学基金资助项目(50775216);精密与特种加工教育部重点实验室开放基金资助项目(JMTZ200705)

摘　　要：针对化学气相沉积碳化硅平面反射镜的材料特性与技术要求,制定了"传统研抛+离子束抛光"的工艺方法,并在一块口径为100mm的试件上进行了验证。首先基于加工效率和亚表面损伤选择合理的工艺参数,并采用磁流变抛光斑点法测量各道工序的亚表面损伤,并以此为依据规划下一道工序的材料去除量;然后分析抛光表面粗糙度的影响因素,在此基础上对抛光工艺参数进行优化,获得表面粗糙度均方根方差值为0.584nm的超光滑表面,并控制工件的面形误差;最后采用离子束抛光进行精度提升,使工件的低频和中频误差均大幅下降,最终工件的面形精度均方根方差值达到0.007λ(λ=632.8nm),表面粗糙度均方根方差值为0.659nm。According to the material characteristics anti technical requirementsof CVD SiC flat reflecting mirrors, a technique combining ＂classic lapping and polishing＂ with ＂ion polishing＂ was proposed and proved on a Ф100mm sample. Firstly the reasonable processing parameters were selected considering machining efficiency and subsurface damages. Then the subsurface damage in each procedure was measured by ＂MRF spot method＂. It served the purpose of determining the material removal thickness in the next procedure. Then the factors influencing surface roughness were analyzed, and the Rq value of surface roughness reaches 0. 584nm through optimization of polishing parameters. At the same time the shape error of the mirror was controlled. At last, the shape accuracy was improved by ion figuring, which decreases the low frequency errors and medium frequency errors apparently. The final shape accuracy and surface roughness reach 0. 007λ （λ=632.8nm） and 0. 659nm respectively.

关 键 词：化学气相沉积碳化硅 超光滑 亚表面损伤 离子束抛光 

分 类 号：TH16[机械工程—机械制造及自动化]