YU Meiling ¹, LI Yueming ¹, ZHAO Lin ¹, XIE Zhipeng ^{1, 2}, WANG Chang’an ^{1, 2}
(1. School of Materials Science and Engineering, Jingdezhen Ceramic Institute, Jingdezhen 333403, Jiangxi, China; 2. State Key Laboratory of New Ceramic and Fine Processing, Tsinghua University, Beijing 100084, China)

Abstract: BNw/Si₃N₄ porous wave-transparent composite green bodies prepared by gel casting method were sintered in multi-function sintering furnace at 1750 ℃ in flowing N₂ to prepare BNw/Si₃N₄  porous wave-transparent composite with better comprehensive properties.Mercury porosimeter, scanning electron microscope and X-ray diffractometer were used to research pore diameter distribution, SEM images and phase composition, respectively. The mechanical and dielectric properties were tested and the influence of solid content and BNw content on mechanical and dielectric properties were analyzed. The results show that the flexural strength of BNw/Si₃N₄  porous wave-transparent composite could be enhanced by increasing solid content and decreasing BNw content, however, the dielectric property could be improved by increasing BNw content. The BNw/Si₃N₄ porous wave-transparent composite with flexural strength of 83.2 MPa and dielectric constant of 3.02 was prepared with the solid content at 16 vol% and the BNw content at 2.5wt.%.

Key words: BNw/Si₃N₄ ; porous; wave-transparent; gel-casting