Influence of cold deformation on the aging behavior of the Al-Mg-Si alloy

The ann of the present work is to study the effect of the cold delonnanon followed by heat treatment on the microstructure and the mechanical properties of an Al-Mg-Si alloy. Differential scanning calorimetry intheates that precipitation of the metastable beta '' phase occurs in the temperature range (220-260 degrees C) for the solution treated and then quenched alloy to room temperature. The exploitation of the DSC curves by the Kissinger method has shown drat the activation energy value of the precipitation reaction is about 83.1 k J /mol The amount of 30% cold delarmation before aging indicates that the first dissolution reaction at about 50 degrees C and the precipitation temperature is around 240 degrees C Microstructural studies, of the aged cold-deformed sample, revealed the presence of line precipitates embedded in the alpha-aluminium Matrix. At as quenched state ofthe alloy reveals an aging response. The increase ofthe microhardness with the decrease of the elongation is mainly due to the severe strengthening by deformation, and not to the effect of precipitation hardening.