Preparation Process of Silicon Carbide Mirrors

There are mainly three methods for the preparation of silicon carbide materials: reaction sintering, chemical vapor deposition, and hot pressing (or hot isostatic pressing).

Reaction Sintering Method 

Reaction sintering is the most common process for mirror preparation. This process involves the infiltration of reactive liquid silicon into a carbon-containing mirror preform. The silicon reacts with carbon to generate new silicon carbide, which in situ bonds with the existing silicon carbide particles in the preform and fills the remaining pores, resulting in a nearly fully dense mirror blank.

Chemical Vapor Deposition Method 

Chemical vapor deposition involves introducing a gas or a mixture of gases into a reaction vessel at temperatures ranging from 1275°C to 1350°C to obtain a silicon carbide deposition layer on graphite or other substrate materials.

Hot Pressing (or Hot Isostatic Pressing) Method 

The main steps of hot pressing (or hot isostatic pressing) sintering: micron-sized silicon carbide powder, sintering aids, and additives to prevent excessive grain growth are mixed and pre-pressed into a preform. This preform is then sealed with appropriate packaging materials and placed in a pressure chamber, where it undergoes sintering under an appropriate temperature-pressure-time regime.

With the rapid development of aerospace and military affairs worldwide, the application of SiC-based mirrors has become increasingly widespread. Currently, Bena Optics, relying on advanced processing equipment, has accumulated extensive experience in the processing technology of surface-modified SiC-based mirrors. To maintain a leading position in the international competition for SiC mirrors, Bena Optics continuously improves and perfects its existing processing techniques, based on CCOS, IBF, and MRF, and combines various polishing technologies according to different processing needs, adopting a combination polishing technique for optical processing to achieve target precision requirements and better adapt to the needs of advanced optics development.