With the development of military weapons, the demand of weapons is growing. But now 2.5 D silica fiber reinforced silica composites have long production period, high cost,which limited the production and schedule of weapons. This paper studied low cost manufacturing technology from two aspects of fiber preform weaving mode and molding process. The preforms were prepared with needling process.CT images of needling preform, thermophysical properties and mechanical properties and dielectric properties of needling silica fiber reinforced silica composites were studied inthis paper.The results showed that needling SiO2f/SiO2 composites had short production period and low cost, which had good mechanical properties.Tensile strength was 20.1MPa, compressive strength of XY direction was 88.3MPa,bending strength was 52.2MPa. Dielectric contant was less than 3.05 and dielectric loss was less than 8×10-3.
Optical spectroscopy of bismuth-doped pure silica fiber preform