Effect of Hot Extrusion on Microstructure and Tensile Properties of Ca Modified Mg-Mg2Si Composite

Abstract

Effect of 0.05, 0.1, 0.5, 1 and 3 (wt. %) Ca addition and extrusion process on the microstructure and tensile properties of Mg-Mg₂Si metal matrix composite has been studied by the use of optical microscopy (OM) and standard tensile testing. The average size of primary Mg₂Si particles decreased from 34 μm to about 10 μm with the addition of 0.05 (wt.%) Ca and extrusion process and also the size of eutectic Mg₂Si decreased from 20 μm to about 2 μm. The morphology of Mg₂Si particles altered from octahedron to fine polygonal and more round shape and eutectic phases altered to well distuributed fragmented particles on the microstructure that was enhance the mechanical properties in comparison with as-cast specimens. Tensile test showed that UTS value increases with the addition of Ca. The maximum UTS value was achieved with 0.1 (wt.%) Ca addition.