Micromechanical Modeling of the Deformation and Damage Behavior of Al6092/SiC Particle Metal Matrix Composites

To enhance the performance and design of metal matrix composites, it is extremely important to gain a better understanding of how the microstructure influences the deformation and damage behavior of metal matrix composites under different loading conditions. Finite element (FE) analysis can be used to collect certain micromechanical information of composites that is difficult to obtain from experiments. In this work, the effect of the distance between the SiC particles and the loading conditions on the deformation and damage behavior of Al6092/SiC particle composites is investigated under different strain rates (i.e., 1 x 10(-4), 2 x 10(-4), and 4 x 10(-4) s(-1)). A program is developed to generate the 2D micromechanical FE model with 17.5 vol.% SiC particles. Based on the scanning electron microscopy images, the FE model contains four SiC particle sizes (3.1, 4.46, 6.37, and 9.98 mu m) with various percentages, which are randomly distributed in the micromechanical Al6092 alloy matrix. User-defined field subroutine was developed and implemented through ABAQUS/Standard based on maximum principal stress and Rice-Tracey triaxial damage indicator to evaluate the formability of the aluminum matrix composite and to predict the brittle and ductile fracture of the SiC particles and the aluminum matrix, respectively, under tensile and shear loads. The results showed that the distribution of SiC particles in Al matrix has a significant effect on the mechanical properties of Al6092/SiC 17.5 particle composites. The formability and damage behavior of composites improve as particle distance increases and strain rate decreases under tensile and shear loading. The fracture initiation toughness of fine SiC particles is higher than that of coarse SiC particles.