Microstructure and mechanical properties of high-temperature free-oxygen rolled Cu/1060Al bimetallic composite materials

Abstract

In this work, Cu/1060Al bimetallic composite materials manufactured by high-temperature free-oxygen rolling process are reported. The results show that with the increase of rolling passes, the microstructure of Cu and 1060Al gradually extends and elongates in the rolling direction, and the interface that has few compounds is dominated by mechanical bonding. It is worth noting that layered fracture occurs during the tensile process. After annealing, the interface changes from mechanical bonding to metallurgical bonding, and the layered fracture is alleviated under the traction of the interface layer. With the increase of annealing time and temperature, the thickness of the interface compounds gradually increase, and the interface compounds from the copper layer to the aluminum layer are Cu9Al4, CuAl and CuAl2, respectively. Annealing at 350 °C for 2 h exhibits the best comprehensive performance, a tensile strength of 138 MPa and an elongation of 64 %. Tensile behavior in the rolled state and annealed state has been discussed based on failure theory, and compound growth after annealing has been analyzed on account of the theories of dynamics and thermodynamics.

Keywords

• High-temperature free-oxygen rolling
• Bimetallic composite materials
• Annealing
• Microstructure
• Tensile properties