EFFECT OF SB-SI ADDITION ON NECKING BEHAVIOUR OF MG ALLOYS

Durgadas.M, G.Ramachandran

Abstract: The present study aims to investigate the necking behaviour of Mg-Sb-Si ternary alloy. Addition of Sb and Si to Mg introduces Mg3Sb2 and Mg2Si intermetallic phases respectively which alters the morphology as well as the mechanical properties of the alloy. Ternary Mg-Sb-Si alloy with varying Si composition were developed by melting pure Mg with required amount of Sb and Si. Optical results of the alloy indicates the presence of rod shaped Mg3Sb2 phase which effectively refines the grain. Mg2Si phase in form of a Chinese Script shape developed as a result of Si addition improves the tensile strength of the alloy. Analysis of necking behaviour using Comsol Multiphysics software is performed incorporating the data obtained from the tensile tests. Large plastic strain approach is selected since there is a multiplicative decomposition between the elastic and plastic deformation. Double dogleg Solver is employed to solve the problem considering the nonlinearity of the problem. It is inferred from the analysis that Mg3Sb2 enhances plasticity whereas Mg2Si induces brittle fracture.

Keywords: Ternary alloy, Si addition, Sb addition, Intermetallics, Necking behaviour and Comsol etc…

DOI: https://doi.org/10.15623/ijret.2014.0305087