Microstructures and mechanical properties of Cu/Al compound materials during thermal cycle

Abstract

Cu/Al compound materials, named as copper-clad aluminum bus bars, are widely used in heat dissipation of modern engineering. The thermal cycle tests were conducted at 200, 250 and 300 °C for different cycle times, respectively. Effects of thermal cycle temperatures and thermal cycle times on microstructures and mechanical properties of the interface were studied. The results show that the width of bonding layer and bond strength are significantly affected by thermal cycle temperatures and times. Nonetheless, the variety or the quantity of intermediate compounds is scarcely influenced. Al2Cu, Cu9Al4 and CuAl were identified on the interface. With the increase in cycle times, grains of the material grew up. However, grains of the interface grew up more apparently than those of Cu and Al. The knowledge may be applied in the establishment of service condition and quality evaluation of material.