Improving the Mechanical Properties of AZ31 Sheet by Adding Nano-Tc4 Particles

Achieving a balance between strength and ductility is of utmost importance for Magnesium matrix composites (MMCs). In this study, AZ31 sheets reinforced with 0.4, 0.7, and 1.0 wt.% nano-TC4 (Ti-6Al-4V) particles were prepared by stir casting coupled with hot extrusion process. In addition to analyzing the microstructure of the extruded composite sheets, the tensile properties were also investigated. The results showed that the incorporation of nano-TC4 particles led to a reduction in texture strength and a refinement of the grains. As a result of the formation of semicoherent orientation relations at the TiAl/Mg and Ti3Al/Mg interfaces, strong interfacial bonding was established between the TC4 nanoparticles and the AZ31 matrix. Compared with the AZ31 sheet, the composite sheet with 0.7 wt.% nano-TC4 particles exhibited the best comprehensive tensile properties. The primary factors contributing to the improvement of mechanical properties were mismatch of coefficient of thermal expansion (CTE) between TC4 nanoparticles and AZ31 matrix, grain refinement, Orowan strengthening mechanism, and strong interfacial bonding.