Preparation and Properties of Sintering Additives Coated Si_3N_4 from Heterogeneous Nucleation Processing

作     者：Juxian ZHANG, Jinjun FENG and Longqiao GAOBeijing Vacuum Electronics Research Institute, 100016 Beijing, China[ Manuscript received January 18, 2001, in revised form April 24, 2001] 

作者机构：Beijing Vacuum Electron. Res. Inst. Beijing 100016 China 

出 版 物：《Journal of Materials Science & Technology》 (材料科学技术（英文版）)

年 卷 期：2002年第18卷第1期

页      面：34-36页

核心收录：

学科分类：080903[工学-微电子学与固体电子学] 0809[工学-电子科学与技术（可授工学、理学学位）] 0817[工学-化学工程与技术] 0806[工学-冶金工程] 08[工学] 080501[工学-材料物理与化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 0703[理学-化学] 0802[工学-机械工程] 0801[工学-力学（可授工学、理学学位）] 0702[理学-物理学] 

基　　金：State Key Lab. Of New Ceramics and Fine Processing of Tsinghua University 

主　　题：Si3N4 powder Sintering additives Zeta potential Rheological property 

摘      要：The sintering additives such as Al2O3 and/or Y2O3 were coated on the surfaces of Si3N4 particles via heterogeneous nucleation processing using a buffered pH solution as the precipitation reagent. They nucleated and grew only on the surfaces of Si3N4 and did not form sol particles in solution by TEM observation. The isoelectric point (IEP) of coated Si3N4 was different from that of as-received Si3N4. The IEP of AI(OH)3-coated Si3N4 occurred at pH8.4, which is close to that of alumina. When AI(OH)3-coated Si3N4 particles were coated with Y(OH)3, the IEP of coated Si3N4 powder shifted from pH8.4 to pH9.2, similar to that of yttria. In addition, the rheological data showed that Al2O3 and/or Y2O3 coated Si3N4 suspension is nearly Newtonian and that added Si3N4 suspension shows a shear rate thinning behavior.