α-Si_3N_4晶种对层状多孔氮化硅陶瓷性能的影响  

Effects of α-Si_3N_4 seeds on properties of porous laminated silicon nitride ceramics

作　　者：鲁元[1] 杨建锋[1] 陆伟忠[1] 高积强[1] 陕绍云[1] 

机构地区：[1]西安交通大学金属材料强度国家重点实验室,西安710049

出　　处：《中国科技论文在线》2009年第4期263-267,共5页

基　　金：国家自然科学基金(50772086);高等学校博士学科点专项科研基金(20060698008);国家高技术研究发展计划(863计划)(2007AA03Z558)

摘　　要：利用二氧化硅在氮气中的碳热还原反应,原位制备氮化硅多孔陶瓷。由于反应中存在大量的质量损失,烧结后可望形成高气孔的材料。通过改变原料中α-Si3N4晶种与二氧化硅和碳粉的相对含量,获得了气孔率可控的多孔氮化硅陶瓷。以此种控制多孔氮化硅气孔率的工艺为基础,制备三层层状多孔氮化硅陶瓷,考察中间层的成分和层间界面对层状多孔氮化硅陶瓷微观组织和力学性能的影响。当中间层与表面层的收缩率相差较大时,虽然是弱界面结合,但产生的界面残余应力对层状多孔氮化硅的力学性能非常有利;当中间层与表面层的收缩率和气孔率接近时,弱界面结合转变为强界面结合。所制备的三层层状多孔氮化硅陶瓷具有优异的力学性能。The porous silicon nitride ceramics were prepared in situ by the use of SiO2 through carbothermal reduction in nitrogen.There was a great lot of mass loss in this reaction,so it was expected to create the high porosity materials.The porosity controlled porous silicon nitride was obtained through changing the relative content of α-Si3N4,SiO2 and C.The three layered porous laminated silicon nitride ceramics composites were fabricated by this technique.The influences of composition of intermediate layer and interface between layers on the microstructure and mechanical properties of porous laminated silicon nitride ceramics composites were studied.When the difference in the linear shrinkage between the intermediate layer and superficial layer was large,even if the interface bonding strength between the layers was weak,the residual stress was favorable to mechanical properties.While the difference in the linear shrinkage between the intermediate layer and superficial layer became small,and the interface bonding strength between the layers changed from weak to strong,the flexural strength increased.So the porous laminated silicon nitride ceramics composites showed good mechanical properties.

关 键 词：材料学 层状多孔氮化硅陶瓷 碳热还原反应 界面残余应力 

分 类 号：TQ174.1[化学工程—陶瓷工业]