Effect of seed particles content on texture formation of Si_3N_4 ceramics by gel-casting in a strong magnetic field  

作　　者：Zhi-Gang Yang Jian-Bo Yu Chuan-Jun Li Kang Deng Zhong-Ming Ren Qiu-Liang Wang Yin-Ming Dai Hui Wang 

机构地区：[1]Shanghai Key Laboratory of Modern Metallurgy and Materials Processing,Shanghai University [2]Institute of Electrical Engineering,Chinese Academy of Sciences

出　　处：《Advances in Manufacturing》2015年第3期193-201,共9页先进制造进展（英文版）

基　　金：supported by National Basic Research Program of China(Grant No.2011CB610404);Shanghai Science and Technology Committee(Grant Nos. 09510700100,135211011020,and 08DZ1130100)

摘　　要：In this paper, the textured Si3N4 ceramics were prepared by adding seed particles during gel-casting in the magnetic field of 6 T, followed by pressureless sintering. The effect of pH on the stability and dispersibility of Si3N4 slurry and the effect of seed particles content on texture formation of SiaN4 ceramics were both studied. Those results showed that the slurry with good stability and dispersibility was obtained when pH was about 11.6. The a or b-axis of Si3N4 particles or crystals was aligned parallel to the direction of the magnetic field in the magnetic field of 6 T. The degree of texture of Si3N4 ceramics further increased during sintering. With the increasing of additional β-Si3N4 particles in the magnetic field of 6 T, the degree of texture increased from 0.19 without seed particles to 0.76 with 9% （mass fraction） seed particles. The increase of seed particles content promoted the texture formation of Si3N4 ceramics.In this paper, the textured Si3N4 ceramics were prepared by adding seed particles during gel-casting in the magnetic field of 6 T, followed by pressureless sintering. The effect of pH on the stability and dispersibility of Si3N4 slurry and the effect of seed particles content on texture formation of SiaN4 ceramics were both studied. Those results showed that the slurry with good stability and dispersibility was obtained when pH was about 11.6. The a or b-axis of Si3N4 particles or crystals was aligned parallel to the direction of the magnetic field in the magnetic field of 6 T. The degree of texture of Si3N4 ceramics further increased during sintering. With the increasing of additional β-Si3N4 particles in the magnetic field of 6 T, the degree of texture increased from 0.19 without seed particles to 0.76 with 9% （mass fraction） seed particles. The increase of seed particles content promoted the texture formation of Si3N4 ceramics.

关 键 词：Silicon nitride GEL-CASTING High magnetic field TEXTURE Pressureless sintering 

分 类 号：TQ174.1[化学工程—陶瓷工业]