ZHAO Zhongjian, LEI Jingxuan, SHEN Huaxiang, SHI Jianbo, WU Hao
(Shanghai FRP Research Institute Co. Ltd. Shanghai 201404, China)
Abstract: In order to meet the performance requirements of the new type of missile radome materials, porous Si3N4 ceramics were prepared by using cold isostatic pressing forming process and non-pressing protection sintering process, with fibrous Si3N4 powder as the main raw material. The effects of the process parameters, such as granularity of the raw materials and the sintering assistant and the sintering temperature, on properties of the samples were studied. By selecting raw material with appropriate particle size and process parameters, the porousSi3N4 ceramics exhibited flexural strength of 154.53 MPa, porosity rate of 52.0%, density of 1.54 g/cm3 and dielectric constant of 3.28. Such porous Si3N4 ceramics can be used to fabricate high-performance missile radomes.
Key words: silicon nitride ceramics; radome; fibrous Si3N4 powder; isostatic pressing forming process; non-pressing protection sintering process