Improving tensile and compressive strengths of magnesium by blending it with aluminium

Abstract

In the present study, Mg based composite containing Al particles was fabricated by blending the Al particles in the Mg powder, followed by hot compaction, two directional microwave sintering and hot extrusion. Microstructural characterisation of the as extruded composite samples revealed a fairly uniform distribution of aluminium with some minor clustering and minimal porosity in the composite. X-ray diffraction results indicate the presence of Al2Mg3 intermetallics at the interface between Mg and Al. Mechanical properties characterisation revealed that the addition of Al particles resulted in an increase in macrohardness, interfacial microhardness, 0.2% yield strength and ultimate tensile strength (both in compression and tension). However, the ductility of the composite was found to be decreased by the addition of Al particles in the Mg matrix. The fractured samples after tensile testing showed a brittle mode of fracture with cleavage steps; however, the fractured sample after compression test showed the presence of single crack with multiple shear band formations. © 2010 Institute of Materials, Minerals and Mining.