Texture characteristics and tensile deformation behavior of Cu/Al layered composites prepared by cast-rolling method

Abstract

The cast-rolling composite method was used to create a Cu/Al layered composites with thickness of 5 mm. The organizational structure, and strain distribution of the composites, were characterized using SEM, TEM, and EBSD. The mechanical characteristics of the composites was determined, and the evolution pattern of the interface under different strains were observed, the microstructures and tensile deformation behaviors of the test material was analyzed. The results show that the microstructure of the test material showed a multilevel layered structure, and at the interface, an Al2Cu + Al4Cu9 intermetallic compounds (IMCs) with a thickness of 380 nm produced. The Al layer's grain size displays a gradient distribution at the micron scale. There are certain differences in Al grain morphology and strain distribution between the rolling direction (RD) and transverse direction (TD). And there are large differences in the grain orientation of the Al grains along the normal direction (ND). There are some twins in the Cu layer, and the grains have no obvious preferential orientation. Cu/Al composites have a higher plasticity than pure Cu and pure Al. In the process of tensile fracture, the cracks are first initiated in the interface layer, but did not expand directly in the longitudinal direction, and after the interfacial restraining effect reached the limit, expansion of cracks into the Cu and Al layers and eventual fracture of the test material. The toughening mechanism of the test material was also analyzed.

Keywords

• Cu/Al layered composites
• Microstructure
• Mechanical properties
• Deformation behavior