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

Authors: S. Jayalakshmi; Q. Dezhi; S. Sankaranarayanan; M. Gupta

Addresses: Department of Mechanical Engineering, National University of Singapore (NUS), Engineering Drive 1, Singapore 117 576, Singapore ' Department of Mechanical Engineering, National University of Singapore (NUS), Engineering Drive 1, Singapore 117 576, Singapore ' Department of Mechanical Engineering, National University of Singapore (NUS), Engineering Drive 1, Singapore 117 576, Singapore ' Department of Mechanical Engineering, National University of Singapore (NUS), Engineering Drive 1, Singapore 117 576, Singapore

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 Al₄C₃ 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 CO₂ incorporation and the processing methods on the microstructural and mechanical properties of the alloys are discussed.

Keywords: magnesium alloys; composites; in situ method; gas-liquid process; CO2 incorporation; carbon dioxide; microstructure; mechanical properties; casting; disintegrated melt deposition; extrusion; hardness; yield strength; tensile strength.

DOI: 10.1504/IJMMP.2013.057066

International Journal of Microstructure and Materials Properties, 2013 Vol.8 No.4/5, pp.283 - 298

Published online: 07 Oct 2013 *

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