Fiber Reinforced Fused Silica for Hypersonic Radome Applications,

During the past few years interest in composite materials having a use temperature above 300 deg C has increased greatly. Because ceramics offer substantial increases in use temperature, much of the research has been concerned with ceramic-matrix composites. The research reported here has been undertaken as a first step in an attempt to develop a fiber reinforced fused silica composite for hypersonic radome applications. In order to maintain isotropy in the composite material and to preserve the low and very temperature-stable dielectric properties of the matrix fused silica material, it was decided to use high purity silica fibers as the reinforcement. Fused silica is an inherently low strength and low modulus material. Having an elastic modulus of about 4.5 x 10 to the 6th power almost any fiber used could increase this value considerably.