Dielectric and Mechanical Properties of Porous Si3N4-BN Ceramic Composites
Recently,ceramic composites with low dielectric constant,low loss tangent,high flexural strength and high thermal shock resistance have received a considerable attention as candidate materials for certain high speed radome.In this paper,Si3N4-BN ceramic composites were fabricated by dry-press processing and cold isostatic pressing,with α-Si3N4 and BN as starting powder,Al2O3 and Yb2O3 as sintering additives,PMMA as pore-forming agent.After sintering for 2 h at 1750 ℃,porous Si3N4-BN ceramic composites with a three-point bending strength of 50~120MPa and a dielectric constant of 3.2~4.4 at 7~18 GHz frequency were obtained.The sintered body was mainly β-Si3N4 grains; BN was dispersed in the grains.The formation of β-Si3N4 grains was demonstrated by X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) respectively.Furthermore,the influence of the BN content on the dielectric and mechanical properties was also studied.The porous Si3N4-BN ceramic composites showed a lower dielectric constant and shrinkage.For above excellent properties,Si3N4-BN ceramic composites have been became one of the most hopeful candidate materials for high speed radome.
Si3N4 BN radome ceramic composites
Jianpeng Dou Xiaolin Liu Jingtao Ma Xuping Lin
State Key Lab of New Ceramic and Fine Processing,Institute of Nuclear and New Energy Technology,Tsin State Key Laboratory of Organic-Inorganic Composites,Beijing University of Chemical Technology,Beiji State Key Lab of New Ceramic and Fine Processing,Institute of Nuclear and New Energy Technology,Tsin
国际会议
The Seventh China International Conference on High-Performance Ceramics (第七届先进陶瓷国际研讨会(CICC-7))
厦门
英文
854-857
2011-11-04（万方平台首次上网日期，不代表论文的发表时间）