Effect of Ca addition on the microstructural and mechanical properties of AZ51/1.5Al 2O 3 magnesium nanocomposite

Abstract

In the present study, new AZ51/1.5Al 2O 3-1Ca magnesium nanocomposite was successfully synthesized by simultaneously adding 2 wt. % aluminum, 1 wt.% Ca and 1.5 vol.% nano-sized Al 2O 3 (50 nm) into AZ31 matrix using an innovative disintegrated melt deposition technique. AZ51/1.5Al 2O 3 nanocomposite was developed following the same processing route except adding Ca. All nanocomposite samples were then subsequently hot extruded at 400°C and characterized. Microstructural characterization studies revealed uniaxial grain size, reasonably uniform distribution of intermetallics and minimal porosity. Results also showed that the Ca addition into AZ51/Al 2O 3 nanocomposite helped to reduce the average grain size. Physical properties characterization revealed that addition of Ca reduced the coefficient of thermal expansion when compared to Ca free nanocomposite. The presence of Ca also assisted in improving overall mechanical properties including microhardness, 0.2% yield strength and ultimate tensile strength while the ductility was compromised.