Bond strength and formability of an aluminum-clad steel sheet

The production of an aluminum-clad steel sheet by the cold rolling process is a more efficient and economical approach compared with the other types of processes utilized for the production of such sheets. In this process, high plastic deformation of two metals, aluminum and steel, is necessary to create the cold bonding between the intermediate surfaces. Therefore, the work-hardened sheet must be annealed in order to obtain a high formability. Heat treatment of the sheet is, however, difficult due to the formation of a brittle intermetallic compound of aluminum and iron at the interface between the layers during heat treatment. In this investigation, the formability of these sheets was measured using the Erichsen cupping test technique. Also, the bond strength was evaluated by macroscopic examination of the surfaces of Erichsen cup specimens. The results indicate that there is an optimum annealing temperature and time leading to a high bonding strength as well as enhanced formability. © 2003 Elsevier B.V. All rights reserved.