颗粒团聚对Al基SiC颗粒增强复合材料的流变形为影响

Effects of Particle Clustering on the Flow Behavior of SiC Particle Reinforced Al Metal Matrix Composites

摘要:

基于微观组织的有限元分析模型，研究颗粒团聚对Al基SiC颗粒增强金属基复合材料流变行为的影响。通过建立的3种增强颗粒分布的胞元模型（一个团聚现象、两个团聚现象和随机分布），分析讨论基体和增强颗粒中的等效应力和等效应变的分布规律，以此为基础，获得3种颗粒分布模型下的SiC颗粒增强Al基复合材料的应力应变曲线。结果表明：颗粒增强金属基复合材料的流变行为和力学响应与增强颗粒的分布非常敏感，但在弹性变形阶段这种影响就相对较弱。从增强颗粒的最大主应力分布来看，颗粒团聚增加了SiC颗粒开裂的概率。从基体的静水应力分布来看，颗粒团聚将促进早期的界面脱粘和在韧性基体中形成微空洞。

Abstract:

The particle distribution of particles-reinforced metal matrix composites (MMC) plays an important role. Thus it is essential to study the effect of the particle clustering behavior on the mechanical response of MMC. This paper reported the microstructure-based finite element analysis (FEA) of MMC to evaluate the clustering behavior, in which three models were established including one-clustering, two-clustering and random particles arrangement. Based on the analysis, the distributions of the von Mises effective stress and of the strain in the matrix and in the particles were obtained and analyzed, respectively. The results show that the mechanical responses in the particles and the matrix are sensitive very much to the particle clustering. Additionally, the overall stress-strain curves of the three models were depicted. It is indicated that during the elastic deformation, the elastic responses of the composites are less affected by the particle clustering. Further, the maximum principal stress in the particles and the hydrostatic stress in the matrix for the three models were investigated. The results reveal that the percentage of the particle cracking in the particle clustering model is higher compared with that in the particle random distribution model.