Development of Nano-composites Based on Magnesium Alloys System AZ31B

Abstract

The objective of this PhD project was to develop new advanced lightweight structural nanocomposites based on magnesium alloy system AZ31B, by addition of: (a) nano-alumina particulates, (b) nano-alumina particulates and calcium element, and (c) nano-alumina and copper particulates, respectively. All these composite formulations were synthesized using disintegrated melt deposition technique. Initially, three different volume percentages of nano-Al2O3 (0.66%, 1.11%, and 1.5%) were incorporated into the AZ31B matrix. The nanocomposite (AZ31-1.5Al2O3) which exhibited an excellent failure strain (29.5%) but reduced yield and ultimate tensile strength was selected and added with difference weight percentages of calcium and copper, respectively. To improve oxidation properties, 1wt%, 2wt% and 3wt% of calcium were added into the nanocomposite (AZ31B-1.5Al2O3). Finally, to improve strength, 10wt% and 18wt% of copper were added into AZ31B-1.5Al2O3 nanocomposite. The processing, microstructural, physical, thermal and mechanical properties and oxidation behavior of the nanocomposites were diligently studied. Insight into mechanisms governing deformation, strengthening and oxidation of the composites was provided. The results suggest that these composites have significant potential in diverse engineering applications.