Material advantage
1. Lightweight and high stiffness: silicon carbide than stiffness is four times that of the traditional glass of the same caliber of weight was only about a quarter, demand for spacecraft weight loss.
2. The thermal stability, coefficient of thermal conductivity is higher than the glass two orders of magnitude, at a much lower temperature control difficulty, adapt to extreme temperature environment in space.
3. The optical properties, surface coating after visible light to infrared reflectivity by more than 95%, meet the demand of high resolution imaging.
Traditional large aperture mirrors use microcrystalline or quartz glass.
Manufacturing technology breakthrough
1. Mirror billet preparation: a similar "tofu" colloidal molding process, the micron grade silicon carbide powder billet lens, support complex lightweight structure, three kinds of preparation route below. China Changchun Optical Machinery Institute has successfully prepared the world's largest single silicon carbide mirror blank (4.03 meters) by solving the problem of 4-meter mirror blank sintering through 5 tests.
2. Precision machining: mirror billet preparation is completed, enter the optical precision machining (technology) as shown. Magnetorheological polishing improves the accuracy of 4-meter mirror shape to 15.2 nm (equivalent to the ground flatness error of Beijing Fifth Ring Road <1 mm). 3D printing technology In 2024, China will realize 0.6m silicon carbide mirror 3D printing, solving the problem of large processing errors and high costs of traditional processes.
3. The coating technology: first rectangular magnetron sputtering coating equipment, film thickness nonuniformity control within 5%, ensure high reflectivity.
Application
1. 4 m caliber reflector: the world's largest reflectors, sic monomer can be clearly observed ground car sunroof details, applied to the national foundation of large photoelectric system.
3. European Extremely Large Telescope (E-ELT) : In mirror splicing technology, CVD-SiC is used to correct the mirror unit (the thermal expansion coefficient matches the primary mirror glass-ceramics).
Challenge and trend
1. Technological complexity: long sintering period are 5 to 6 months (single), polishing time consuming (4 m lens to 64 months).
2. The future direction: combined with 3 d printing to achieve greater diameter (such as meters) reflector rapid manufacturing, promote commercial application.
Through the full link independent technology (mirror blank → processing → coating), China has broken the foreign monopoly and installed the strongest "cornea" for the "clairvoyant".
FOUNTYL TECHNOLOGIES PTE. LTD. is located in singapore, specialized at ceramic material forming, sintering & machining technology, serving semiconductor users, products are silicon carbide chuck, porous ceramic vacuum chuck, air floating table, ceramic end effector and ceramic guide rail, welcome to contact us for further potential business cooperation.
