Thermal expansion study of particulate reinforced aluminum matrix composite material

The thermal expansion behavior of Duralcan particle reinforced composite materials was investigated. Initially, the temperature dependence of the CTE of Al-Si alloy containing SiC reinforcement particles ranging from 10 to 40% in volume was experimentally examined and compared with standard theoretical model predictions. In addition, the effects of reinforcement volume fraction and nature of the composite constituents during thermal cycling between 25 and 350°C were determined for Al-Si alloy containing between 10 and 40% SiC particles and Al alloy having 40% alumina in volume. Accurate experimental CTE measurements were made using a high precision Thermomechanical Analyzer system. Silicon carbide reinforced composite average CTE values were bounded by two elastic CTE theoretical models consisting of Schapery and Kerner predictions over the 25--350°C interval for reinforcement volume fractions between 10 and 40%. The CTE mismatch between the particles and the matrix does not appear to be the only factor influencing the expansion response of the composites. Indeed, the nature of the composite constituents also plays an important role by influencing the ductility and bonding of the particle-matrix interface.