Interface Microstructure and Diffusion Mechanism in the Diffusion Bonding of Copper and Aluminum

摘要

Using vacuum diffusion bonding technology, reliable Cu/Al diffusion joint was obtained under the condition of 520-540℃ x60 min and pressure 12.5 MPa. On the base of interface microstructure analysis by means of microsclerometer, SEM and EPMA etc., diffusion mechanism in the Cu/Al diffusion interface was researched. The test results indicated that the brittle intermetallic compounds were easily formed to make the toughness of the diffusion joint decreased when the diffusion Al over definite amount. The main diffusion mechanism in vacuum diffusion bonding of Cu/Al is vacancy movement. There is the exponential relationship between Cu and Al mutual diffusing and vacancy liquid and with time to attenuate and convergence.