LEI Jingxuan, HU Wei, WU Hao, ZHAO Zhongjian, WANG Pingping, SHI Zhiwei

( Department of Ceramic Research, Shanghai FRP Research Institute, Shanghai 201404)

Abstract: In this paper, the porous silica ceramic materials and parts are fabricated by introducing the pore-forming agents into the materials by pelletizing method, aging the slip in the vacuum conditions and casting the slip under pressure. The influence of the content of the pore-forming agents on porous silica ceramic materials is investigated. In addition, the factors which affect the porous ceramic density uniformity are also discussed. The results showed that porous silica ceramic prepared by this method is an optional core material for broadband radome, and it has a flexural s trength of 18MPa, a dielectric constant of  2.5, and a loss tangent lower than 5 ×10^{- 4}.

Key words: porous silica ceramic, pelletizing, pore- forming agent, pressure casting, broadband