高温下短纤维增强金属基复合材料界面的微观结构和热残余应力状态研究

STUDY ON THE MICROSTRUCTURE CHARACTERISTICS AND THERMAL RESIDUAL STRESS STATES OF INTERFACE IN SHORT FIBER REINFORCED COMPOSITE AT ELEVATED TEMPERATURE

利用透射电镜观察了 δ- Al2 O3短纤维增强 Al- 5 .5 Mg合金复合材料界面在不同环境温度下的微观结构特征。同时 ,基于该类复合材料的单纤维模型 ,利用弹塑性有限元分析方法 ,研究了在不同温度下界面热残余应力的大小和分布情况 ,并讨论了热残余应力对界面行为的影响。最后 ,讨论了界面的微观结构和热残余应力特征对复合材料整体性能的影响。研究表明 ,不同环境温度下 ,界面具有不同的微观结构和热残余应力特征 ,这些特征的变化将引起复合材料整体性能的明显变化。

The microstructure characteristics of interface in δ Al 2O 3 short fiber reinforced Al 5.5Mg alloy composite at different temperatures were observed by TEM. In the meantime, based on the single fiber model of the short fiber reinforced metal matrix composite, the thermal residual stress states of interface were calculated by an elasto plastic finite element method. The effects of the interfacial thermal residual stress on the mechanical behavior of interface at various temperatures were also discussed. At last, the effects of varied microstructure features and thermal residual stress states of interface on the whole mechanical behavior of the composite were analyzed. It is shown that the microstructure features and thermal residual stress states of interface change with the variation of ambient temperatures, which then results in the different mechanical behavior of the composite.