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In this work, Cu/Al8011/Al1060 trilayered composite with an ultrathin copper layer was fabricated successfully by the hybrid process of cast-rolling and hot-roll-bonding. The effects of heat treatment were investigated on the microstructure and mechanical behavior of the composite. The results showed that annealing temperatures above 300 ​°C led to the formation of new intermetallic compounds that joined their initial counterparts. Also, the interface growth was fast above 340 ​°C. It was found that the annealing temperature of 320 ​°C led to the optimal tensile properties of the composite. Through rolling, hard-brittle IMCs imposed intense plastic strains on the surrounding regions, resulting in further grain refinement of both metals in the vicinity of the interface. Although the kernel average misorientation of the trilayered composite was almost identical with the Cu/Al8011 bimetal, its amount was considerably decreased after heat treatment, as the distorted structure changed into a nearly strain-free one using the restoration phenomenon. The SEM-based in-situ tensile test showed that crack initiation occurred within the IMCs and propagated into the Cu strip, leading to its early fracture. However, the strength-displacement curve during in-situ tensile deformation did not decrease significantly due to the ultrathin copper layer.

This work studied the interface morphology, microstructure behavior, and mechanical properties of the fabricated trilayered Cu/Al8011/Al1060 composite. In this regard, the roll-casted Cu/Al8011 bimetal was subjected to the hot-roll-bonding process with Al1060 at a thickness reduction of 47%. As a result, the hot-roll-bonding broke the produced nonuniform continuous interface within the copper and aluminum during the roll-casting process. The corresponding interface from the copper side includes Al4Cu9, AlCu, and Al2Cu, respectively. Additionally, SEM-based in-situ tensile deformation revealed that the initiated cracks at the Cu/Al8011 interface propagated into the copper layer that led to its fracture before the aluminum. Based on the FEM results, the effective stress distribution of the Cu strip is not homogeneous at the deformation zone. Moreover, the thickness reduction of the Cu and Al layers was respectively lower and slightly higher than that of the trilayered composite, indicating that plastic deformation mainly occurred at the aluminum matrix due to its large plasticity amount.