Elastic constants and isotropy considerations for Particulate Metal-Matrix Composites. A multi-particle, cell-based approach

The elastic behavior of Particulate Metal-Matrix Composites was studied by means of a multi-particle cell model, which includes a number of prismatic particles. An algorithm has been developed to produce spatial distributions of prismatic particles within a cell of periodic geometry. For an aluminium alloy reinforced with SiC particles, its elastic constants were obtained by FEM analysis of multi-particle cells representing various abstract micro-structural scenarios, defined as combinations of specific values of reinforcement volume fraction and particle aspect ratio, in different conditions of particle orientation. Results are classified according to isotropy characteristics of the different micro-structural scenarios under study. Using the well-known Halpin-Tsai equation, the results were extended to other intermediate fractions, providing new values for the Halpin-Tsai 's' parameter. It is also shown that results can be extended to other systems such as steel reinforced with SiC particles using the new 's' values.