Prediction of the thermomechanical behavior of particle-reinforced metal matrix composites

The objective of this paper was to predict the thermomechanical behavior of 2080 aluminum alloy reinforced with SiC particles using the Mori-Tanaka theory combined with the finite element method. The influences of particle volume fraction, stiffness, aspect ratio and orientation were examined in terms of effective Young's modulus, Poisson's ratio and coefficient of thermal expansion (CTE) of the composite. The microstructure induced local stress and strain field was obtained through the numerical models of the representative volume element. Results suggested that particle volume fraction had significant impact on the effective Young's modulus, Poisson's ratio and CTE of the composite. Stiffer particles could improve the effective Young's modulus of the composite, while the overall sensitivity of the effective Poisson's ratio and CTE with respect to the particle stiffness was minimal. Particles with larger aspect ratio generally led to a composite with increased effective Young's modulus, as well as reduced Poisson's ratio and CTE. The overall material properties of the composite were insensitive to the particle aspect ratio beyond 10. The particle orientations significantly impacted the effective material properties of the composite, especially along the longitudinal direction. Random 3D dispersed particles exhibited the effective isotropic behavior, whereas anisotropy has been observed for random 2D and unidirectional aligned particles. Our results could help create tailorable bulk composite. (c) 2012 Elsevier Ltd. All rights reserved.