Research Progress of Optical Fabrication and Surface‐Microstructure Modification of SiC

Abstract

SiC has become the best candidate material for space mirror and optical devices due to a series of favorable physical and chemical properties. Fine surface optical quality with the surface roughness (RMS) less than 1 nm is necessary for fine optical application. However, various defects are present in SiC ceramics, and it is very difficult to polish SiC ceramic matrix with the 1 nm RMS. Surface modification of SiC ceramics must be done on the SiC substrate. Four kinds of surface-modification routes including the hot pressed glass, the C/SiC clapping, SiC clapping, and Si clapping on SiC surface have been reported and reviewed here. The methods of surface modification, the mechanism of preparation, and the disadvantages and advantages are focused on in this paper. In our view, PVD Si is the best choice for surface modification of SiC mirror.

Effect of Sintering Temperature on the Properties of Highly Electrical Resistive SiC Ceramics as a Function of Y2O3-Er2O3 Additions

“…Silicon carbide (SiC) ceramic has enjoyed a good reputation for its excellent mechanical, chemical, and thermal properties [1][2][3][4]. It has been widely used as structural materials, such as mechanical seals [5], heat exchangers [6], and optical mirrors for space telescopes [7]. However, it has more applications besides structural materials.…”

High productive machining of C/SiC preceramics

“…The second operation for the optical surface creation is associated with the smaller amounts of material removal (several percent of a workpiece volume) but is highly demanding to accuracy. Final optical surface of space mirrors should be characterized by roughness less than 1 nm 6 …”

“…Final optical surface of space mirrors should be characterized by roughness less than 1 nm. 6 A number of methods are known for primary machining of advanced ceramics: diamond turning, 7 fixed abrasive grinding, 4,8 atmospheric-pressure plasma and laser processing, 9,10 ultrasonically assisted machining, 11,12 and abrasive waterjet milling. 13 Nevertheless, these methods do not provide, in general, both high productivity and accuracy of silicon carbide processing.…”

Investigation on the laser ablation of SiC ceramics using micro‐Raman mapping technique

“…SiC ceramics have gradually been identified as the most promising material for optical mirrors in large-scale space optical devices and high-power laser systems [1,2]. As such high-performance optical mirror, it must possess stable and high-quality surface to resist deformation and damage from laser attack.…”