Speaker
Description
The Al-6XXX alloys are widely used in automotive applications for their high strength to weight ratio. The desired properties are achieved by precipitate hardening through the process of artificial aging at elevated temperatures. However, these alloys undergo natural aging at room temperature which is undesirable, and a mechanistic understanding of the early stages of precipitation in natural aging is still lacking. We perform off-lattice kinetic Monte Carlo simulations of vacancy migration using a near DFT-accurate machine-learning potential for Al-Mg-Si to study the dynamics of vacancy-solute interactions during natural aging. Early-stage clusters of Si and Mg atoms are found to trap vacancies, in agreement with indirect evidence for 'vacancy prisons'. The clusters and trapping times are studied qualitatively and quantitatively, and the implications of the early-stage kinetics on subsequent artificial aging is discussed.
Abhinav C. P. Jain, Daniel Marchand, Albert Glensk, Michele Ceriotti, W. A. Curtin
| Speaker Country | Switzerland |
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