(中南大学 粉末冶金国家重点实验室，长沙 410083)
摘 要: 基于修正的剪切滞后模型、Eshelby等效夹杂理论以及Weibull统计分布，发展SiC增强铝基复合材料屈服应力的本构模型。选取多种铝合金，包括工业纯铝、Al-Mg-Si合金、Al-Cu-Mg合金以及Al-Zn-Mg 合金，作为复合材料的基体材料进行屈服应力的测试，以验证模型的准确性。模型考虑变形过程中SiC颗粒失效(包括颗粒脱粘和颗粒断裂)对复合材料屈服应力的影响。结果表明：复合材料的屈服应力随着SiC颗粒体积分数的增加而增加，但随着SiC颗粒尺寸的增加而降低；该力学模型比传统的修正剪切滞后模型更加准确，这表明SiC颗粒失效对复合材料的屈服应力产生重要的影响。
关键字: SiC/Al复合材料；屈服应力；载荷转移；Weibull统计
SiC reinforced aluminum alloy composites
（State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China）
Abstract:A constitutive model for the yield stress of SiC reinforced aluminum alloy composites was developed based on the modified shear lag model, Eshelby’s equivalent inclusion approach and Weibull statistics. Several types of aluminum alloys including industry pure aluminum, Al-Mg-Si alloy, Al-Cu-Mg alloy and Al-Zn-Mg alloy were chosen as the matrix materials to verify the accuracy of the model. The failure of the SiC particles including particle debonding and cracking on the yield stress of composites during the deformation process was considered in the model. The results show that the yield stress of the composites increases with increasing volume fraction of SiC particles, but it decreases with increasing size of the SiC particles. The prediction of the present developed constitutive model agrees much better with the experimental data than the traditional modified shear lag model, which indicates that the failure of SiC particles has important effect on the yield stress of the SiC reinforced aluminum alloy composites.
Key words: SiC/Al composites; yield stress; load transferring; Weibull statistics
