Characterization of the interfacial micro-zones in C18150Cu/8011Al laminated composites

Abstract

Cu/Al laminated composites are a category of structure-function integrated materials with excellent comprehensive performance, but traditional composites prepared using pure Cu and Al are currently facing the problem of insufficient strength. In this paper, C18150Cu and 8011Al were selected to prepare 3.8 mm-thick high strength and high conductivity Cu/Al laminated composites by cast-rolling + cold rolling + annealing. Their interfacial micro-zone microstructures were characterized using SEM, TEM and TKD, and the relationship between their microstructure and performance was explored. The results show that the interfacial structure is a three-layer (Al4Cu9, AlCu, Al2Cu) alternating with a two-layer (Al4Cu9, Al2Cu) interface of intermetallic compounds. This particular interfacial layer structure can be attributed to the fact that when the cold-rolled fracture interface regrows at a heat treatment temperature of 320 °C, the banded Cr precipitation zone near the interface hinders the diffusion of the Cu element and locally thins the interface thickness. In addition, the presence of nano and submicron Cr phases, nano Cu5Zr phases, and twinned crystals on the Cu side of the near-interfacial micro-zone. By efficiently utilizing the properties of C18150Cu and by having a relatively reasonable interface thickness after heat treatment. The composites in this study exhibit more advantageous mechanical properties compared to other reports.

Keywords

• High strength and high conductivity
• Cu/Al laminated composites
• Microstructure