Microstructure and mechanical properties of Mg-Al alloys with in situ Al4C3 phase synthesised by CO2 incorporation during liquid state processing

Abstract

In this work, Mg-Al alloys containing 7 wt.% and 9 wt.% Al were synthesised by the incorporation of carbon dioxide during casting, using the disintegrated melt deposition technique and were characterised after extrusion. Microstructural studies revealed fine-grained structure and phase analyses of Mg-7Al-CO2 and Mg-9Al-CO2 showed the presence of Al 4C3 phase formed in situ during processing. Evaluation of mechanical properties of these alloys phase showed improvements in hardness, yield strength and ultimate tensile strength when compared to those without the incorporation of CO2. The observed enhancement in mechanical properties was attributed to the dispersion strengthening effect brought forth by the in situ Al4C3 phase. Based on the processing-structure-property correlation, the significant influence of CO 2 incorporation and the processing methods on the microstructural and mechanical properties of the alloys are discussed. Copyright © 2013 Inderscience Enterprises Ltd.