Growth characterization of intermetallic compounds at the Cu/Al solid state interface

Cu/Al cold-rolled composite plates were annealed in the temperature range of 573~773 K. The growth mechanism of intermetallic compounds formed at the Cu/Al solid-state interface was analyzed from the point of view of diffusion kinetics. After annealing, the interfacial reaction layer of the sample consisted of three kinds of intermetallic compound: Al2Cu adjacent to Al, Al4Cu9 adjacent to Cu and AlCu between Al2Cu and Al4Cu9. The formation sequence of the intermetallic layers was Al2Cu, Al4Cu9, and AlCu. The results show that the growth of Al2Cu, Al4Cu9 and AlCu layer were governed by reaction-controlled mechanism in the previous period and by diffusion-controlled mechanism in the latter period in the annealing temperature range of 573 to 773 K, and the higher annealing temperature, the earlier the reaction-controlled stage ends for three kinds of intermetallic compound.