Fabrication and Characterization of Al-Cu Laminated Composites

Introduction: Laminated metal matrix composites are a class of metal matrix composites with desirable mechanical and physical properties that can be used widely in transportation, electrical, and thermal industries. Methods: In this study, aluminum-copper laminated composites with favorable mechanical and physical properties were fabricated in different thicknesses by hot pressing, with or without heat treatment. The effect of heat-treatment time on intermetallic phase formation and mechanical properties was then investigated. Results: After composite making, the microstructure, the hardness, tensile properties, and impact behavior were studied. Optical microscope and SEM examinations showed ideal bonding between the copper and aluminum layers at their interface without any cracks or porosities. The XRD analysis showed Al2Cu intermetallic compounds formation at the interface of aluminum-copper sheets. Also, the analysis showed a eutectic reaction between the metals interface, Al2Cu (θ), and Al2Cu-Al (Cu) (α) phases were formed. Discussion: The hardness and tensile strength of the composites were increased, and the impact strength of the composite was decreased with increasing annealing time. The hardness profile shows that the hardness value increases in the area near the copper-aluminum interface, which is due to the greater amount of metal compound phases. With increased heat-treatment time, the composites exhibited brittle behavior, and their impact strength decreased. Conclusion: The composites with 30 minutes of heat treatment showed maximum tensile strength, elongation, and impact strength because of their small size and low amounts of the interface intermetallic phases in the laminated composites.