空间相机反射镜碳化硅材料性能测试

通过对SiC样件加工研磨及反射率等性质的测试,得到了材料的性能数据,分析了用SiC材料制备反射镜毛坯的几种方法的优缺点。采用Lanmda-9分光光度计,对SiC在不同表面镀硅、镀银、以及镀硅后再镀银的条件下进行了反射率测试,得出在镀硅再镀银条件下,反射率最高,达到98%的结果。利用Wyko干涉仪对国产SiC长条形样镜进行研磨分析测试,测得表面粗糙度值为6.27 nm。该材料在某型号离轴三反光学系统中作为反射镜得以应用和验证,测得被加工后,镜面面形PV值达到0.068 λ,RMS值为0.01 λ(λ=632.8 nm)。此结果表明,材料的性能达到了可加工可应用的要求。

Characteristic test of SiC for space camera's mirror

The performance data of SiC materials were obtained by processing and polishing SiC and testing its reflectivity,and the advantages and disadvantages of some fabrication methods of SiC mirror roughcast were analyzed. The reflectivity of SiC specimen was tested under different conditions of surface processing including Si-coated or Ag-coated surfaces and Ag-recoated on Si-coated surface with Lanmda-9 Spetrophotometer. The highest reflectivity is 98% under the condition of recoated Ag on coated-Si surface. Domestic long strip SiC mirror was polished and tested. The result shows that the surface roughness is 6.27 nm with Wyko interferometer. As a reflection mirror of off-axis three reflect optics system,the material performance was validated in a mirror surface figure with PV value of 0.068 λ, and RMS of 0.01 λ (λ=632.8 nm),the results indicate that performance of SiC can meet the requiremerits of the space camera's mirror.