Investigation of forming limit diagram and mechanical properties of the bimetallic Al/Cu composite sheet at different temperatures which fabricated by explosive welding

Abstract

This research aims to investigate the mechanical properties, fractography and formability of Al/Cu two-layer composite sheets at three temperatures (23 °C, 120 °C and 220 °C). The bimetal sheet was fabricated by the explosive welding method. The anisotropy of the Al/Cu bimetallic composite sheet was investigated. The result showed significant anisotropy in the Al/Cu composite sheet due to the explosive welding process. The Vickers hardness measurements demonstrated that the hardness in both aluminum and copper sides increased because of the work hardening phenomenon. The fractography of the surfaces was investigated by the scanning electron microscope after tensile tests to study the effect of temperature and the direction, which the samples prepared for the tensile test with respect to the explosion direction, on the mechanism of the fracture. For the tensile test, the samples were prepared parallel to the detonation direction [Formula: see text] and two other directions with respect to the explosion direction [Formula: see text] from the AA1100/Cu10100 bimetallic sheet. Finally, the forming limit diagram of the Al/Cu composite sheet was determined at the three mentioned temperatures. The results demonstrated that temperature and the direction had a considerable effect on the mechanism of the rupture and formability. As the temperature of the specimen rises, the regions that brittle fracture happened became less and the formability improved significantly. The formability of the Al/Cu composite sheet enhanced about 34.8% when the temperature increased from 23 °C to 120 °C and 67.5% when it increased from 120 °C to 220 °C.