The formation and growth of intermetallic compounds during interdiffusion of Al/Cu bimetals
Fei Cao, Peng Zhang, Juntao Zou, Tongmin Wang
Abstract
Abstract The diffusion couple technology was used to study the formation and growth of intermetallic compounds (IMCs) of Al/Cu bimetals at the temperature range of 480-540 o C for 5-20 h. The interfacial microstructure formed during interdiffusion and the growth kinetics of IMCs are determined. The results show that four different kinds of IMCs (Al 2 Cu, AlCu, Al 2 Cu 3 and Al 4 Cu 9 ) were formed at the Al/Cu interface, which is related to the interfacial diffusion reaction and the migration of phase interfaces. The growth of IMCs is mainly controlled by volume diffusion, and follows a parabolic growth kinetics, i.e. L = kt 1/2 . Based on the effective heat of formation model and Gibbs free energy change calculation, the Al 2 Cu is predicted to form first and the formation sequence of the four IMCs is Al 2 Cu, Al 4 Cu 9 , AlCu and Al 2 Cu 3 .