Study of precipitation kinetics in a super purity Al-0.8 Pct Mg-0.9 Pct Si alloy using differential scanning calorimetry

A study of precipitation kinetics in a super purity Al-0.8 Pct Mg-0.9 Pct Si alloy using differential scanning calorimetry was performed. An aluminum alloy containing 0.8 wt pct Mg and 0.9 wt pct Si (in wt pct) was cast as 35 × 230 × 535 mm direct chill (DC) ingot. The ingot was scalped 1/4 mm on each rolling face, homogenized at 560 7C for 6 hours, and hot and cold rolled in several passes to the final thickness of 1.0 mm. Specimens for differential scanning calorimetry (DSC) were punched from the cold-rolled material and subjected to appropriate heat treatments before conducting DSC experiments. The DSC experiments were carried out in an argon atmosphere using a DU PONT* 2100 instrument equipped with a programmable recorder. It is observed that the subpeak temperature range shifts to higher temperature with natural aging, although the shape of the DSC curve is not affected significantly.