Preparation of AlN/Cu composites through a reactive infiltration process

•A novel process is developed to infiltrate Cu melt into AlN powder compact.•The thermal conductivity of the AlN/Cu composites can reach 100 W/m K.•A reaction infiltration process is developed.

The wetting of copper (Cu) melt on aluminum nitride (AlN) is very poor. In the present study, a reactive infiltration process is developed to prepare AlN/Cu composites. With the help of a sulfur-containing atmosphere, the Cu–S and Cu–O compounds are formed at elevated temperatures. Due to the presence of these reaction phases, the infiltration of copper melt into a powder compact of aluminum nitride and yttrium oxide becomes possible. After infiltration, the sulfur within the powder compact is absorbed by the yttrium oxide. Dense AlN/Cu composite with a thermal conductivity of 100 W/m K can be prepared at a temperature as low as 1400 °C.