Mechanism study of rare earth Y enhancing A356 tensile performance: Deep learning potential and Ab initio molecular dynamics

HP Wu and XM Chen and LF Yang and DX Zheng and J Zhou and EH Zhang and RJ Jia and PJ Liu and YM Chen, MATERIALS TODAY COMMUNICATIONS, 44, 111868 (2025).

DOI: 10.1016/j.mtcomm.2025.111868

Rare earth element Y has demonstrated a significant effect in inhibiting the precipitation of the silicon phase in A356 aluminum alloys. To investigate the influence of Y on the microstructure of aluminum alloys, this study employs a combination of ab initio molecular dynamics (AIMD) and deep potential molecular dynamics (DPMD) simulation methods, complemented by experimental validation. Simulation results indicate that Y strengthens the interaction between Si-B, enhancing the diffusion of Si, B, and Ti atoms. Leads to the formation of TiB2 nucleation sites, which in turn suppresses the aggregation of Si. Similarly, the incorporation of Y reduces both the size and number of Si clusters within the alloy during processes of smelting, solidification, and heat treatment. Results in a transformation of Si clusters from elongated to spherical shapes, the elimination of the MgSi phase, and a reduction in the size of pore defects, ultimately leading to their disappearance. Experimental findings corroborate that the Si phase in the A356 +Y alloy transitions from bar- and flake-like structures to shorter rods and spheres, accompanied by a refinement in grain size. Consequently, the ultimate tensile strength, yield strength, and elongation of the alloy increase to 191.53 MPa, 174.02 MPa, and 11.70 %, respectively, reflecting gains of 7.46 %, 17.68 %, and 19.02 % compared to the A356 alloy without Y.The structures observed in DPMD are consistent with AIMD and experimental observations, thus verifying the consistency and accuracy of this multi-scale approach."

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