莫来石基复合材料研究进展

莫来石(3Al2O3· 2SiO2)陶瓷具有抗蠕变能力高、热膨胀系数和导热系数低、抗腐蚀性和抗热震性优异的特点,是一种很有前景的高温结构材料.它最显著的优势是强度和韧性随着温度升高不仅不会下降反而有所提高.然而,莫来石的室温力学性能较差,限制了它的广泛应用.针对如何提高莫来石的室温强度和韧性,目前的研究集中于利用第二相进行改性,取得了一定成果.本文介绍了非连续相(颗粒、晶须、短切纤维)和连续纤维增强莫来石基复合材料的研究现状,包括制备工艺、微观结构和主要性能,指出了存在的问题和今后的发展方向.

Progress in the Research of Mullite Ceramic Matrix Composites

Mullite(3A12O3·2SiO2) has the characteristics of high resistance to creep,corrosion and thermal shock,and has a low thermal expansion coefficient and a low thermal conductivity,which make it a structural material with good potential foreground.The most outstanding advantage of mullite is that its flexural strength and fracture toughness rise with the temperature.However,it has relatively poor mechanical properties at room temperature,which limits its applications.In order to improve the flexural strength and fracture toughness at room temperature,many researches have been conducted,which focus on the method of adding the secondary phase and make some progress.This article introduces the current condition of mechanical properties improvement by discontinuous phase(particles,whiskers and short fibers) and continuous fibers,including the fabrication,microstructures and main properties,and points out the exiting problems and the tendency in the future.