A numerical model for predicting effective thermal conductivities of alumina/Al composites

Abstract

This article describes a novel technique for manufacturing functionally graded materials with tailored properties for thermal management. These materials are ceramic/metal composites with a gradient microstructure, elaborated by producing a porosity gradient preform made of alumina phase subsequently infiltrated by the molten aluminum alloy (Al) phase. In order to model these particulate composites and to evaluate their effective thermal conductivities, a numerical approach based on both discrete element method and finite element method has been developed. The study presented here deals with alumina/Al composites without gradient microstructure and is conducted to numerically investigate the effects of the particle size distributions and the interconnection sizes between particles on the effective thermal conductivity. The situation in which an interfacial thermal resistance is present between both phases of composites to simulate a non ideal contact has also been considered.