Reinforced AZ91D magnesium alloy with thixomolding process facilitated dispersion of graphene nanoplatelets and enhanced interfacial interactions

Abstract

Magnesium matrix nanocomposites reinforced with graphene nanoplatelets (GNPs) additives have long been considered as exciting prospects among nanotechnology applications. Here, the thixomolding process, an extremely efficient dispersing technology, was applied to prepare AZ91D magnesium alloy- GNPs nanocomposites with different GNPs contents (0, 0.1, 0.3, 0.6, 0.9 and 1.2 wt%). The effects of screw rotate rate ( R S ) and injection velocity ( V I ) on microstructures, GNPs dispersibility and mechanical properties were investigated. The GNPs, fairly uniform dispersion in the nanocomposites, were incorporated in the α-Mg grains, not only in the grain boundaries. Strong bonding interfaces between GNPs and alloy matrix were established because of the formed MgO nanoparticles leading to the formation of Mg/MgO semi-coherency interface and MgO/GNPs interface. Compared with other previously reported results, a relatively higher overall efficiency was achieved in the prepared magnesium matrix nanocomposites. The developed technology has a potential for large-scale industrial production of not only thin-walled complex parts, but also thick-walled products such as automobile parts with complex structure.