Development of new magnesium based alloys and their nanocomposites

In the present study, 1 and 2 wt.% of aluminum were successfully incorporated into magnesium based AZ31 alloy to develop new AZ41 and AZ51 alloys using the technique of disintegrated melt deposition. AZ41–Al2O3 and AZ51–Al2O3 nanocomposites were also successfully synthesized through the simultaneous addition of aluminum (1 and 2 wt.%, respectively) and 1.5 vol.% nano-sized alumina into AZ31 magnesium following same route. Alloy and composite samples were then subsequently hot extruded at 400 °C and characterized. Microstructural characterization studies revealed equiaxed grain structure, reasonably uniform distribution of particulate and intermetallics in the matrix and minimal porosity. Physical properties characterization revealed that addition of both aluminum and nano-sized alumina reduced the coefficient of thermal expansion of monolithic AZ31. The presence of both Al and nano-sized Al2O3 particles also assisted in improving overall mechanical properties including microhardness, engineering and specific tensile strengths, ductility and work of fracture. The results suggest that these alloys and nanocomposites have significant potential in diverse engineering applications when compared to magnesium AZ31 alloy.

. Engineering stress–strain diagrams of AZ31, AZ41, AZ51 alloys and their Al2O3 nanocomposites.Figure optionsDownload as PowerPoint slideHighlights
► New AZ41 and AZ51 magnesium alloys and their Al2O3 nanocomposites are developed.
► The CTE of monolithic AZ31 alloy decreases with both elemental Al and nano-sized Al2O3 addition.
► Microhardness of AZ31 alloy increases with the Al and nano-sized Al2O3 addition.
► Newly developed AZ alloys and their nanocomposites exhibit good overall tensile properties.