Effects of Cu and pre-aging on the clustering behavior in Al-Mg-Si alloys

The clustering behaviors in two Al-Mg-Si alloys with and without Cu after different pre-aging and natural aging conditions were systematically quantified using microhardness, differential scanning calorimetry (DSC), and atom probe tomography. Cu addition slowed down the natural aging process after either solutionizing or preaging regardless of pre-aging temperature and time, and reduced the negative effect of post pre-aging natural aging on beta precipitation by changing the composition of the Mg and Si rich clusters. This work complements the limited literature on the effect of long natural aging, and provides insights into the impacts of alloy composition and storage time on precipitation behavior during subsequent artificial aging.

Automated summary

This study systematically quantified the clustering behaviors in two Al-Mg-Si alloys and found that the addition of Cu can slow down the natural aging process and reduce the negative effect of post pre-aging natural aging on beta precipitation by changing the composition of the Mg and Si rich clusters.