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arXiv · 2411.07921

Atomic-scale study on core-shell Cu precipitation in steels: atom probe tomography and ab initio calculations

Xiao Shen·YiXu Wang·Zigan Xu·Bowen Zou·Enzo Liotti·Richard Dronskowski·Wenwen Song
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Abstract

The present work investigates the atomic interactions among Cu, Al, and Ni elements in bcc-iron matrix, focusing on the formation mechanism of nano-sized core-shell Cu precipitates. Using a combination of atom probe tomography (APT), density functional theory (DFT) cal-culations, and molecular dynamics (MD) simulations, the study provides insights into the atomic-scale migration tendencies of these elements in the supersaturated solid solution sur-rounding Cu precipitate in the martensite phase of a medium-Mn steel. The results show that Ni and Al atoms were not expelled by Cu atoms but were instead attracted to the bcc iron matrix, forming a stable co-segregation in the outer shell. This phase effectively surrounded the nano-sized Cu precipitate and prevented its rapid growth, contributing to improved me-chanical properties. The findings offer a theoretical method for developing Cu-contaminated circular steels by utilizing DFT calculations to unravel bonding preferences and assess the po-tential for forming a stable precipitation phase around nano-sized Cu precipitates.

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Xiao Shen, YiXu Wang, Zigan Xu, Bowen Zou, Enzo Liotti, Richard Dronskowski, Wenwen Song. 2024-11-12. Atomic-scale study on core-shell Cu precipitation in steels: atom probe tomography and ab initio calculations. https://arxiv.org/abs/2411.07921

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