摘要
本文分析了SiCw/ZTM系复合材料的显微结构及其与力学性能的关系,特别讨论了四方相氧化锆含量及其稳定化程度对增韧的影响。调节氧化锆相中稳定剂Y_2O_3的固溶量可在ZTM复合材料中实现微裂纹增韧和一定程度的相变增韧。包含氧化锆增韧和晶须补强两种效应的SiCw/ZTM多相复合材料中,晶须补强与微裂纹增韧呈加和规律,晶须补强与相变增韧的复合能产生协同增韧效果,但这要求非常仔细地控制稳定剂含量及四方氧化锆晶粒度,以使其中四方氧化锆具备适当的稳定度。
The microstructure and toughening behavior of SiCw/ZTM multiphase composites
have been studied, especially the effect of the content and the stability of t-ZrO_2 on their toughening
mechanism were discussed. Microcrack toughening and some degree of transformation toughening
have been achieved by varying amounts of Y_2O_3 addition to adjust the degrees of t-ZrO_2 stabilization
in zirconia toughened mullite (ZTM) composites. Further improvements were obtained by combining
zirconia toughening with whisker reinforcement in SiCw/ZTM multiphase composites. An additional
toughness contribution resulted from the interaction of the stressinduced tranformation and whisker
reinforcement by carefully contralling the degrees of t-ZrO_2 stabilization.
基金
国家自然科学基金资助项目
关键词
莫来石
复合材料
显微结构
mullite
whiskers
transformation toughening
whisker reinforcement
synergistic toughening
