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arXiv · 1407.6412

Atomic-scale pathway of early-stage precipitation in Al-Mg-Si alloys

Vahid Fallah·Andreas Korinek·Nana Ofori-Opoku·Babak Raeisinia·Mark Gallerneault·Nikolas Provatas·Shahrzad Esmaeili
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Abstract

Strengthening in age-hardenable alloys is mainly achieved through nano-scale precipitates whose formation paths from the atomic-scale, solute-enriched entities are rarely analyzed and understood in a directly-verifiable way. Here, we discover a pathway for the earliest-stage precipitation in Al-Mg-Si alloys: solute clustering leading to three successive variants of FCC clusters, followed by the formation of non-FCC $GP$-$zones$. The clusters, which originally assume a spherical morphology ($C1$), evolve into elongated clusters and orient themselves on $\{111\}_{Al}$ ($C2$) and subsequently on $\{100\}_{Al}$ planes and $<$$100$$>_{Al}$ directions ($C3$). We also analyze the association of quenched-in dislocations with clustering phenomena. The results of this work can open a new frontier in advancing alloy-process-property design for commercially-important age-hardenable Al alloys.

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Vahid Fallah, Andreas Korinek, Nana Ofori-Opoku, Babak Raeisinia, Mark Gallerneault, Nikolas Provatas, Shahrzad Esmaeili. 2014-07-24. Atomic-scale pathway of early-stage precipitation in Al-Mg-Si alloys. https://arxiv.org/abs/1407.6412

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