多孔氮化硅陶瓷高温强度及其断裂行为的研究

项目名称： 多孔氮化硅陶瓷高温强度及其断裂行为的研究

项目编号： No.51302290

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 一般工业技术

项目作者： 姚冬旭

作者单位： 中国科学院上海硅酸盐研究所

项目金额： 25万元

中文摘要： 多孔氮化硅陶瓷作为新一代高速导弹天线罩的候选材料，其目标使用温度在1400 C以上。经过十几年的发展，多孔氮化硅已经在成型工艺、烧结工艺、微观形貌调控、室温强度等方面取得了长足进步。但是，在高温力学性能的评价及相关影响机理的研究上明显滞后，成为阻碍多孔氮化硅陶瓷发展的瓶颈之一。本项目将以近年来本研究团队在多孔氮化硅陶瓷制备科学和常规性能评价等方面的系统研究为基础，表征材料在空气气氛中不同温度下的高温强度，以高分辨透射电镜、能量损失谱、高温内耗谱为核心分析手段，研究不同晶粒尺寸、气孔尺寸、第二相、界面化学对高温氧化和强度的影响，深入探讨影响多孔氮化硅高温强度的内在因素，为设计具有优良高温力学性能的天线罩材料提供理论指导。

中文关键词： 天线罩；多孔氮化硅；氧化；晶界；

英文摘要： Porous Si3N4 ceramic is a promising candidate for the next generation high march missile radome, whose target application temperature is above 1400 C. During the past several decades, many progress and developments have been achieved in the processing, sintering techniques, microstructure control and room temperature strength improvement for porous Si3N4 ceramic. Up to now, however, the evaluation of the mechanical properties at high temperature and analysis of correlative influence mechanisms are still an problem to be solved, which is one of the bottle-necks hindering the application of porous Si3N4 ceramic. Based on the systematic researches of the material preparations in our research group during recent years, this aim of the project is going to evaluate the high temperature bending strength in air at different temperatures. By using the high resolution transmission electron microscopy (HRTEM), electron energy loss spectroscopy (EELS) and high temperature internal friction spectrum (HTIFS) as the key characterization techniques, the high temperature oxidation properties and high temperature bending strength affected by different grain size, pore size, second phases and grain boundary phases will be studied. the intrinsic factors which affect the high temperature flexural strength of porous Si3N4 ceramic wi

英文关键词： radome；porous silicon nitride；oxidation；grain boundary；