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Phase-field simulation of Mg-Al alloy solidification
- Date: 13.10.2015
- Time: 05:00
- Place: 10th International Conference on Magnesium Alloys and Their Applications, Jeju, South Korea
We present the results of the microstructure evolution simulation during solidification of Mg-Al alloys. The full process of solidification is simulated using the free phase-field simulation library "OpenPhase". Consecutive nucleation and growth of primary alpha-Mg phase and secondary beta-Mg phase is simulated. The influence of the main processing control parameters such as cooling rate, nucleation density and Aluminum concentration on the as cast Mg alloy microstructure has been invesigated. The obtained simulation results closely match experimental observations.
Using a dual scale approach, a zoomed in region of the interdendritic eutectic melt was simulated. A system consisting of a melt channel between two primary alpha-Mg dendrites is cooled below the eutectic point. A rapid coverage of the alpha-Mg dendrites by beta-Mg phase promotes the formation of divorced eutectic solidification microstructure.
It consists of a mixture of tertiary alpha- and secondary beta-Mg. The formation of such a divorced eutectic microstructure is an important factor for the improvement of the corrosion resistance of the cast alloy. The obtained simulation results show remarkable agreement with experimentally observed microstructures.
The proposed simulation approach can later be used for computational design of Mg-alloys with desirable corrosion properties.