Evaluation of interface structure and high-temperature tensile behavior in Cu/Al8011/Al5052 trilayered composite

This paper dealt with the combined processing of roll-casting and hot-rolling to fabricate high-performance Cu/Al8011/Al5052 composite with ultrathin copper thickness. It was shown that the intermetallic compounds formed at the Cu/Al interface include Al4Cu9, AlCu, and Al2Cu from the copper side, respectively, in which the CuAl phase has the lowest thickness due to its the high diffusion activation energy. Also, Al2Cu, due to having the lowest amount of Gibbs free energy, was initially formed at the interface, followed by the Al4Cu9 and AlCu phases. Although the room-temperature tensile strength of the trilayered composite is close to each other in both directions, the elongation to failure in the rolling direction is about 37% better than that of the transversal di-rection. Furthermore, no clear slip bands were observed in the uniform plastic deformation zone of the stress strain curve during the high-temperature tensile tests compared to the room-temperature counterparts. Despite the decrease in tensile strength with increasing test temperature, this composite shows good tensile behavior at temperatures below 200 degrees C due to the pure shear fracture mode.