The morphology of eutectic silicon in solidification microstructure is critical to the performance of Al-Si-based alloys. Simulating eutectic Si phase formation has been a challenge in ICME (integrated computational materials engineering) based design and manufacturing of solidification products of Al-Si-based alloys. In this study, our previous three-dimensional (3-D) cellular automaton (CA) model for α-Al dendritic growth was extended to include eutectic (α-Al + Si) transformation in multi-dendrite domains, providing a complete solidification simulation of critically important Al-Si based alloys. The quantitative results of the Si phase in the eutectic microstructure were experimentally validated using scanning electron microscopy and deep etching techniques. The simulation results show a good agreement with the experimental observations and calculations by the Scheil model and lever rule. This 3-D CA model is useful for predicting and optimizing the solidification microstructure including eutectic transformation during solidification processing such as casting, potentially welding, and additive manufacturing.

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A206 aluminum alloy is an important Al‐cast alloy with high mechanical strength. However, its dependence on θ′‐phase for effective strengthening raises concern for its anti‐corrosion performance in service. This paper systematically studies nano‐treating A206 with TiC nanoparticles to investigate its effects on overall corrosion behavior. Immersion tests and electrochemical measurements have been used to understand the nano‐treating contributions to the improved corrosion resistance of A206 under T4 and T6 heat treatment. The results indicate that the pseudo‐dispersion of TiC at or near the grain boundary (GB) and precipitates strengthens the GBs, and more rapid passivation near the TiC‐dense zone introduces a more uniform corrosion feature. The uniform corrosion with rapid passivation greatly facilitates the corrosion control of nano‐treated A206 under T4 and T6 heat treatment, allowing supreme anti‐corrosion stability for high‐strength A206 alloy.

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