A Graded Density SiC Foam for Lightweight Optics

Lightweight silicon carbide optics and structures are extremely important to explore the Structure and Evolution of the Universe. State-of-the-art SiC is too heavy, contains other phases which interfere with producing an acceptable optical surface and is anistropic causing distortions with temperature excursions. In this program a functionally graded density isotropic silicon carbide foam will be formed insitu with a unique high density isotropic SiC structure which has a skin of defect free silicon carbide that can be polished ultra-smooth. The functionally density graded isotropic SiC foam structure containing no other phases will be utilized to produce SiC optics with an areal density less than 1 kg/m2. Sample optics will be delivered to NASA.