放电等离子烧结Si_3N_4陶瓷  

Preparation of Si_3N_4-MgO-CeO_2 with Spark Plasma Sintering

作　　者：杜大明[1] 李养良[1] 李永志[1] 宋士华[1] 

机构地区：[1]九江学院材料科学与工程学院,九江332005

出　　处：《佛山陶瓷》2005年第6期7-10,共4页Foshan Ceramics

摘　　要：本文用放电等离子烧结法制备Si3N4陶瓷,通过排水法测定密度,X射线衍射法测定物相变化,透射电镜进行微观形貌的观察。发现在烧结过程中,当高于1450℃时MgO-CeO2与氮化硅粉末表面的SiO2反应形成硅酸盐液相,促进烧结致密化,冷却后形成玻璃相留在晶界,氮化硅的致密化在1500℃接近完成,但高于1550℃时,出现MgO自析晶,微观形貌为相互交织的等轴状的α-Si3N4和柱状的β-Si3N4晶粒。Si3N4-MgO-CeO2 ceramics were prepared by spark plasma sintering (SPS).The densification process,composition and microstructure in Si3N4 ceramics had been studied by means of density,XRD and TEM.The results showed that MgO-CeO2 reacted with the SiO2 to form sufficient liquid phase to densify Si3N4 ceramics at the initial stage of SPS(1450～1550℃).At final stage(>1600℃),the automatic crystallization of MgO reduced the amount of glassy phase that are harmful to the high-temperature properties.Micro-analysis indicated that the typical microstructure of sintered Si3N4 was made of equiaxed α-Si3N4 crystalline grains and cylindrical β-Si3N4 crystalline grains.

关 键 词：SI3N4陶瓷 放电等离子烧结法 X射线衍射法 微观形貌 氮化硅粉末 烧结致密化 物相变化 透射电镜 烧结过程 SiO2 CeO2 MgO 排水法 硅酸盐 玻璃相 测定 液相 反应 析晶 柱状 

分 类 号：TQ174.6[化学工程—陶瓷工业]