颗粒增强铝基复合材料断裂韧性与拉伸延性的解析模型

Analytic Model for the Fracture Toughness and Tensile Ductility of Particle Reinforced Aluminum Composites

基于Eshelby等效夹杂理论及Weibull统计分布,发展了SiCp/Al金属基复合材料断裂韧性与拉伸延性的力学模型。模型的计算表明:当复合材料受外力时,SiC颗粒所受的力与外加应力呈线性关系。随着外加应力的增加,SiC颗粒所受的力也线性增加。同时,外力作用下SiC颗粒的断裂分数服从Weibull统计分布,即SiC颗粒的总体含量越高,其断裂分数就越高。模型关于约化拉伸延性和断裂韧性的计算与实验结果较为吻合。模型的解析和实验结果都表明:拉伸延性与断裂韧性随SiC颗粒体积分数的增加而减小。在相同体积分数的情况下,拉伸延性与断裂韧性随SiC颗粒尺寸的增加而减小。

A mechanical model for the fracture toughness and tensile ductility of SiCp/Al metal matrix composites has been developed based on the Eshelby theory and Weibull distribution.The model calculation indicates that the stress on the SiC particles has linear relationship with the externally applied stress on the composites.The stress on the SiC particles increases linearly with the increase in externally applied stress.At the same time,the cracking fraction of the SiC particles under the external stress satisfies the Weibull distribution.The cracking fraction of the SiC particles increases as the total volume fraction of the SiC particles increases.The fracture toughness and tensile ductility decrease as the size and volume fraction of the SiC particles increase,which was illustrated by both model calculation and experimental results.