The Effective Properties of Dispersed Composites B4C/2024Al

The paper presents the results of numerical three-dimensional and two-dimensional modeling of the stress-strain state of a dispersed B4C/2024Al composite in the case of statics. The aim of the work was to determine the effective elastic moduli depending on the concentration of boron carbide inclusions by the asymptotic homogenization method and to compare the calculation results with the experimental data. A study was carried out on the basis of digitized photographs of cross sections of the real composite structure obtained using an electron microscope. A specific feature of the study was the application of three scales. First, in the representative volume element, the effective properties of the composite matrix consisting of aluminum with Al4Cu inclusions and "small" B4C particles were calculated. Then, the averaging problem was solved for the averaged matrix and "large" B4C inclusions. The task was posed in the formulations of plane-deformed and plane-stressed states. As a result of calculations, the property of statistical homogeneity and isotropy of both the matrix material and the alloy as a whole was confirmed. Numerical experiments were also carried out for a model three-dimensional structure with inclusions in the form of spheres and ellipsoids with a random orientation and for its two-dimensional cross sections. The calculations confirmed the possibility of using two-dimensional images of the structure to calculate effective modules. A comparison of the effective elastic modules calculated for the model (three-dimensional model) and real structure (plane problem) with experimental data showed close agreement.