High-temperature tensile properties of Mg/Al2O3 nanocomposite

Mg/1.1Al2O3 nanocomposite was synthesized using solidification process called disintegrated melt deposition technique followed by hot extrusion. Microstructural characterization showed that reasonably uniform distribution of reinforcement leads to significant grain refinement of commercially pure magnesium matrix and effectively restricted the grain growth during high-temperature tensile test. Physical properties characterization revealed that addition of nano-Al2O3 particulates as reinforcement improves the dimensional stability of pure magnesium. Mechanical properties characterization revealed that the presence of thermally stable nano-Al2O3 particulates as reinforcement leads to a significant increase in room temperature microhardness, dynamic elastic modulus, 0.2% yield strength, UTS and ductility of pure magnesium and efficiently maintained the strengthening effect up to 150 deg C. Fractography revealed that fracture behavior of magnesium matrix change from brittle to mixed ductile mode with activation of non-basal slip system in room temperature to complete ductile mode at high temperature due to the presence of nano-Al2O3 particulates.