Elaboration and characterization of a metal matrix composite: Al/AlN

Metal matrix composites consisting of 56.5 vol% aluminum nitride in various aluminum matrices were manufactured. Through the selection of both reinforcement and matrix variables, the thermal properties of the composite were tailored to make it suitable for use in electronic packaging. AlN reinforcement consists of pressed and partially sintered AlN powder to obtain preforms with adjustable porosity. Al-Si aluminum alloys were used as matrices, with Si content ranging from 0 to 22 wt%. The composite exhibits very attractive properties, including a relatively high thermal conductivity (100 W m(-1) K-1), a low coefficient of thermal expansion (9.10(-6) K-1 for an Al-22.5 wt% Si matrix) as well as a good specific strength. Basic models used to predict the thermal and mechanical properties of the composite show a good agreement between theoretical and experimental data, except for thermal conductivity. For this last property, it is assumed that the matrix-reinforcement interface may have an important effect which is Mot taken into account in the theoretical model. Published by Elsevier Science Limited.