Quantitative study of dissolution of Mg2Si during solution treatment in AA6014 alloy

The solution heat treatment of AA6014 sheet is important to meet the required dent resistance in assembled automotive structures. In this study, the effect of solution heat treatment conditions on the Mg2Si particle size distribution and volume fraction were quantitatively investigated using SEM observations, electrical conductivity, and hardness measurements. Precipitation during artificial aging was studied by DSC analysis. After soaking at 570 °C for 1min, the volume fraction of soluble Mg2Si was reduced dramatically from 1.58% to nearly zero. Hardness measurements, EC, and SEM characterization of T4 samples were compared as measures of Mg2Si dissolution.