Abstract
Magnesium based composites containing 2.5wt.% of nano-sized Al2O3 (50nm) particulates reinforcement were synthesized
using an innovative disintegrated melt deposition technique and blend–press–sinter powder metallurgy technique followed by
hot extrusion. Microstructural characterization of the materials revealed uniform distribution of reinforcement, grain refinement
and the presence of minimal porosity. Properties characterization revealed that the presence of nano-Al2O3 particulates led to
an increase in dimensional stability, hardness, elastic modulus, 0.2% yield strength, UTS and ductility of pure magnesium.
Amongst the composites, the ingot metallurgy processed material exhibited superior modulus and ductility while powder metallurgy
processed material exhibited superior yield strength and ultimate tensile strength. The results further revealed that the overall
combination of tensile properties of these materials remained superior when compared to high strength magnesium alloy AZ91
reinforced with much higher weight percentage of SiC. Fractography studies revealed that the typical brittle fracture of pure magnesium
changed to ductile due to the incorporation of nano-Al2O3 particulates. An attempt is made in the present study to correlate
the effect of nano-sized Al2O3 particulates as reinforcement and processing type with the microstructural and tensile
properties of magnesium.
2004 Elsevier Ltd. All rights reserved.
Magnesium based composites containing 2.5wt.% of nano-sized Al2O3 (50nm) particulates reinforcement were synthesized
using an innovative disintegrated melt deposition technique and blend–press–sinter powder metallurgy technique followed by
hot extrusion. Microstructural characterization of the materials revealed uniform distribution of reinforcement, grain refinement
and the presence of minimal porosity. Properties characterization revealed that the presence of nano-Al2O3 particulates led to
an increase in dimensional stability, hardness, elastic modulus, 0.2% yield strength, UTS and ductility of pure magnesium.
Amongst the composites, the ingot metallurgy processed material exhibited superior modulus and ductility while powder metallurgy
processed material exhibited superior yield strength and ultimate tensile strength. The results further revealed that the overall
combination of tensile properties of these materials remained superior when compared to high strength magnesium alloy AZ91
reinforced with much higher weight percentage of SiC. Fractography studies revealed that the typical brittle fracture of pure magnesium
changed to ductile due to the incorporation of nano-Al2O3 particulates. An attempt is made in the present study to correlate
the effect of nano-sized Al2O3 particulates as reinforcement and processing type with the microstructural and tensile
properties of magnesium.
2004 Elsevier Ltd. All rights reserved.
