Finite element modeling of effective thermomechanical properties of Al-B4C metal matrix composites

The present work aims to investigate the influences of thermal residual stresses and material properties on the thermomechanical deformation behavior of Al-B4C composites. Boron carbide-reinforced aluminum matrix composites having 4, 8, and 12 vol% boron carbide were fabricated using squeeze liquid stir casting method for experimental characterization of their microstructure, effective elastic moduli and effective CTEs at room temperature as well as elevated temperatures. Next, the thermomechanical behavior of fabricated composites was investigated using finite element modeling. The effects of thermal residual stresses on the effective material properties were examined by simulating the cooling process of MMCs from processing temperature to room temperature. The effective elastic moduli and the effective CTEs were predicted considering linear elastic as well as elastoplastic deformation of aluminum matrix, and the results obtained were compared with the experimental values. The effects of voids on effective material behavior are studied by simulating the void growth and nucleation using Gurson-Tvergaard-Needleman model.