3D micromechanical analysis of thermo-mechanical behavior of Al2O3/Al metal matrix composites

Abstract

In this paper an elastoplastic finite element model for studying the thermomechanical behavior of Al/Al2O3 particulate composites is proposed. 3D representative volume elements (RVEs) are created to model the microstructures of Al/Al2O3 composites and the finite element models generated from RVEs are used to study the mechanical and thermal expansion properties. In order to study the effect of thermal residual stresses, first the RVEs are simulated for cooling process from sintering temperature to room temperature and thermal residual stress are estimated for different mechanical behaviors of Al matrix. Next, the thermomechanical properties are examined with existing residual stresses. The predicted effective elastic moduli and the coefficient of thermal expansion are compared with the experimental results reported in literature. The FE results have good correlation with the experimental data and the effects of microstructural parameters, voids and properties of the constituents are further discussed. In order to study the influence of voids on the elasto-plastic behavior of composites, the Gurson–Tvergaard–Needleman (GTN) model is applied. The nucleation and growth of voids in composites, under uniaxial tension, is studied.