Solidification processed Mg/Al bimetal macrocomposite: Microstructure and mechanical properties

Abstract

A new bimetal magnesium/aluminium (Mg/Al) macrocomposite containing mm-scale Al core reinforcement was fabricated via casting and hot coextrusion. Characterization revealed fairly uniform Al volume fraction along the extruded rod length attributable to mechanical interlocking between Mg shell and Al core. Major defects were absent and Mg-Al interfacial integrity was good. Thermal stability of the macrocomposite was marginally improved when compared to pure Mg. Results revealed that the presence of the Al core leads to a decrease in strength of Mg, but an improvement in stiffness as well as significant increase in failure strain (144%) and work of fracture (73%) of Mg. An attempt is made in the present study to investigate the effect of presence of mm-scale Al core on the microstructure and mechanical properties of the bimetal Mg/Al macrocomposite. © 2007 Elsevier B.V. All rights reserved.