Influence of rolling deformation on microstructures and mechanical properties of laminated Mg/Zr composites

Abstract

Improving the strength and ductility of magnesium (Mg) alloys is a popular area of research. Many studies have indicated that laminated metal composites can be used to simultaneously yield excellent properties of all their constitutive metals. In this study, laminated Mg/Zr (AZ31/Zr702/AZ31) composites were fabricated by hot rolling-induced bonding. An Mg plate was used as the initial wedge component to obtain a wide range of rolling reductions (40%–70%) in a given Mg/Zr composite, and its microstructures and mechanical properties were then characterized. The results show that rolling reduction greater than 40% was needed to achieve a well-bonded interface for Mg/Mg (AZ31/AZ31) and Mg/Zr composites when rolled at 400 °C. With increasing rolling reduction, the strength of the Mg/Zr composite (∼180 MPa) showed no prominent change, and was higher than that of Mg/Mg composites (∼150 MPa) fabricated by using the same bonding process. In addition, the Mg/Zr composite had significantly higher bonding strength (∼6 N/mm) and ultimate peel strength (∼9 N/mm) than the Mg/Mg composites (∼2.5 N/mm and ∼3 N/mm). Finite element simulations were also used to examine the underlying strengthening mechanisms of the composites. The results here contribute to research on the strengthening and toughening of Mg alloys as well as the fabrication of laminated metal composites.