Predicting effective elastic modulus of CNT metal matrix nanocomposites: A developed micromechanical model with agglomeration and interphase effects

Abstract

Agglomeration and interphase region of fillers are two important factors that affect the mechanical properties of metal matrix composites reinforced with carbon nanotubes (CNT-CMMs). However, most of the existing theoretical models predict an ascending linear in strength for composites with increasing filler content, which disagrees with the experimental results, especially at high filler loading. In fact, at high CNT concentrations, agglomeration and weak interphase region bonding reduce the strength and consequently degrade the mechanical properties of composites. Based on the mean-field theory, we present a novel micromechanical model to predict the elastic modulus of CNT-CMMs by considering the effects of these two factors. Furthermore, we investigate the effect of other parameters such as CNTs aspect ratio, agglomeration amount, interphase layer thickness and modulus, and matrix modulus on the elastic modulus of CNT-CMMs. Finally, we validate our model by comparing it with numerous experimental outcomes from the literature signifies good precision. Using this model, it is possible to optimize the filler value and also maximize the elastic modulus, which can be a powerful tool for designing the CNT-CMMs.