An experimental investigation on the influence of Sn addition and aging time on the mechanical and micro structural properties of AZ80-1.2RE magnesium alloy

Abstract

This study investigated the effect of tin (0, 6, and 9 wt%) and aging time (0, 16, 24, and 32 hrs) on the microstructure and mechanical properties of the AZ80-1.2RE Mg alloy. The results obtained indicate that the addition of Sn improved the mechanical properties. For the AZ80-1.2RE alloy, upon Sn addition, strength of 195 MPa and percentage elongation of 7.6 are observed to be found at 6 wt% Sn, which is attributed to the precipitates of Al2RE, Mg2Sn, and Mg-Sn-RE phases. After heat treatment and aging, the properties of the casted alloys were found to be affected. As aging time increases, small precipitates are observed to be dissolved in primary Mg phase, due to which the properties are found to be decreased from the as-cast condition to aging at 16 hours. The strength of the 6wt% Sn alloy decreased due to the high stress concentration at the large precipitate site during aging from 16 hours to 24 hours and then increased due to the grain boundary strengthening effect at the 32-hour aging time.