Entrance analysis of 7075 Al/Mg–Gd–Y–Zr/7075 Al laminated composite prepared by hot rolling and its mechanical properties

Entrance of 7075 Al/Mg–12Gd–3Y–0.5Zr/7075 Al laminated composites produced by a hot rolling bonding method was investigated. The results showed that using a wedge-end and multi-step process ensured that the assembly of multi-layered plates could enter the rollers area at the beginning of the process. The conventional entrance prerequisite for a single plate during rolling, i.e. having an entrance angle smaller than the friction angle, was not sufficient for multi-layered plates. In addition, a condition for preventing the tail end of the aluminum alloy plates lifting up when these plates come in contact with the rollers must be taken into account. The bonding strength and the ultimate tensile strength of the laminated composite were also studied and it was shown that the mechanical bond played a major role in the bonding strength of the samples produced. The ultimate tensile strength of the laminated composite was lower than that of 7075 Al alloy and higher than that of Mg–12Gd–3Y–0.5Zr Mg alloy. This result could be explained by calculating the stress distribution in the laminated composite under tensile loading.

Research highlights
► Beside the roll bite for a plate, tail of outer plates uplifting was considered.
► Mechanical bond played a major role in the bonding strength.
► Ultimate tensile strength of the composite was higher than that of the Mg alloy.
► Stress distribution in the composite under tensile loading could explain it.