莫来石纤维微观结构调控与力学性能研究

项目名称： 莫来石纤维微观结构调控与力学性能研究

项目编号： No.51302289

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： 康庄

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： 莫来石纤维具有高温强度保持性好、抗蠕变性及抗热震稳定性高的特点，作为耐高温隔热材料及金属及陶瓷基复合材料的增强材料，广泛应用于冶金、化工以及航空航天等领域中。然而，莫来石纤维在高温下晶粒过度生长及纤维内玻璃相导致的蠕变，劣化了其高温性能。如何在无玻璃相加入条件下增加莫来石纤维内晶核密度，降低莫来石结晶温度，使莫来石纤维获得细晶、致密的结构是保证其具有良好高温力学性能的关键。本项目通过向双相莫来石前驱胶体内添加单相莫来石胶体，以单相莫来石胶体低温原位生成的莫来石晶体作为晶核的方法来调控莫来石纤维的结晶结构，避免了玻璃相的加入。在此基础上研究晶核密度对高温下莫来石纤维结晶结构、纤维力学性能的影响。探讨莫来石纤维显微结构与力学性能的关系，为高性能莫来石纤维的制备和性能优化提供借鉴和理论指导。

中文关键词： 莫来石纤维；结构演变；力学性能；结构调控；

英文摘要： Due to its good high temperature strength retention, good creep resistance and high thermal shock resistance properties, mullite fibers were widely used as insulation materials and reinforcement for metal and ceramic matrix composites in metallurgy, chemical industry, aviation, aerospace and other fields. However, the temperature-induced mullite grain coarsening and glass phase induced creep, deteriorated the high temperature mechanical properties of mullite fibers. How to increase the nucleation density and acquire finely grained dense microstructure without introducing glass former in mullite fiber is a key to ensure good high temperature mechanical properties of mullite fibers.In this project, monophasic mullite sol was introduced to diphasic mullite spinning sol to modify the crystallization behavior of mullite fibers, and the introduction of glass formers in mullite fibers were avoid. The monophasic mullite gel crystallizes in situ to form mullite that acts as seed crystals for homoepitactic nucleation during the subsequent transformation of the diphasic mullite gel. Based on this research, the effect of nucleation density on mullite fiber crystal structure and mechanical properties will be investigated. The relationship between microstructure and mechanical properties will also be revealed. This research

英文关键词： mullite fibers；structure evolution；mechanical properties；structure regulation；