Mechanical Properties and Bonding Mechanism of the Mg/Al Clad Sheet Manufactured by the Corrugated Roll

Abstract

In this research, corrugated Mg/Al clad sheet with good interface bonding was prepared with a rolling mill of upper corrugated roll and a lower flat roll under the conditions of 35% reduction and 400 °C. The mechanical properties of the corrugated Mg/Al clad sheet were studied using the transverse tensile test, Vickers microhardness and as well as its bending properties. Moreover, the interface bonding mechanism of the corrugated clad sheet was researched through three-dimensional contour analysis. The results showed that the UTS at the trough position was the highest (~296 MPa), and that the peak position was the lowest (~257 MPa). The maximum fracture EL at the peak position was ~13.4%, while the minimum fracture EL at the trough position was ~10.6%. In the transverse tensile process, the interface cracked first due to the uneven stress distribution in the matrixes. Then, the Mg sheet broke, and finally the Mg/Al clad sheet failed with final fracturing of the Al sheet. The microhardness of interface metal Al at the four positions was higher than that of the interface metal Mg, which was closely related to the dislocation strengthening of the Al sheet. The interface bonding mechanism of the corrugated Mg/Al clad sheet could be divided into four stages: extrusion deformation, rubbing fracture, compound extension and compound completion.