Development of high strength magnesium based composites using elemental nickel particulates as reinforcement

Magnesium based materials due to their inherently low density and ensuing potential to exhibit high specific mechanical properties are actively sought for weight-critical structural application. In the present study, elemental and nickel reinforced magnesium materials were synthesized using an innovative disintegrated melt deposition technique followed by hot extrusion. Microstructural characterization of the composite samples showed uniform distribution of nickel particulates in the matrix material, good interfacial integrity of magnesium matrix with nickel particulates and Mg-Ni based intermetallics, and the presence of minimal porosity. Physical properties characterization revealed that addition of nickel as reinforcement improves the dimensional stability of pure magnesium. Mechanical properties characterization revealed that the presence of nickel reinforcement lead to significant improvement in hardness, elastic modulus, 0.2% yield strength and UTS while the ductility was adversely affected. The results further revealed that the combination of 0.2% yield strength, UTS, and ductility exhibited by nickel reinforced magnesium remained much superior even when compared to high strength magnesium alloy AZ91 reinforced with much higher volume percentage of SiC. An attempt is made in the present study to correlate the effect of nickel as reinforcement and its increasing amount with the microstructural, physical and mechanical properties of magnesium.