Precipitate phase selection and grain boundary morphology in Cu-Ni-Si-Mn alloys: A machine-learning interatomic potential study
Abstract
Alloys inevitably contain interphase boundaries, whose energetics govern nucleation processes and precipitate morphology. In Cu-Ni-Si alloys, Mn addition markedly changes grain boundary (GB) precipitation behavior. While GB precipitation of stable Ni2Si in Mn-free alloys is associated with degraded mechanical properties, Mn addition instead promotes film-shaped Mn6Ni16Si7 (G-phase) precipitation, which is correlated improved mechanical properties. However, the atomic origin of the contrasting GB phase selection and morphology remains unclear. Here we perform machine-learning interatomic potential (MLIP) calculations to investigate the effect of interphase-boundary atomic structure on GB precipitates in Cu-Ni-Si alloys with and without Mn. The MLIP calculations reliably reproduce DFT-level energetics for interfacial bonding and microstructural configurations, and further predict that Mn addition favors GB precipitation of Mn6Ni16Si7 rather than Ni2Si. Experimentally, Mn-free alloys are observed to exhibit irregularly-shaped Ni2Si precipitates with open-boundary-like Cu/Ni2Si interfaces, whereas Mn-added alloys exhibit film-like G-phase at GBs. Large-scale atomistic interface calculations reveal that the coherent interface structure between Cu and Ni2Si favors the formation of plate-like strained Ni2Si precipitates in the matrix. Upon coarsening and stress release, an out-of-phase coherent-like interface can form at GBs, generating a local repulsive region that gives rise to surface-like open-boundary structures and explains the irregular morphology of GB stable Ni2Si precipitates. In contrast, Cu/Mn6Ni16Si7 interfaces remain predominantly incoherent with moderate boundary energies and no pronounced repulsive regime, thereby stabilizing continuous interfacial contact and explaining film-shaped GB precipitation.
Versions
Related
- A GRACE Interatomic Potential for W--Ta Systems: Application to Ta Segregation and Pinning of Shear-Coupled Grain-Boundary Migration
- Cluster-based Structural Similarity for Dataset Visualization and Data Selection for Machine Learning Interatomic Potentials
- PASS: Perturbation augmented space group structure sampling for transferable Fe-O machine learning interatomic potential
- Machine-Learned Interatomic Potential for the Mo-S-Al-O System
- Learning Between the Lines: Interaction Interpolation in a Multi Element Machine Learning Interatomic Potential
BibTeX
@misc{wani2026precipitate,
title = {{Precipitate phase selection and grain boundary morphology in Cu-Ni-Si-Mn alloys: A machine-learning interatomic potential study}},
author = {Aadil Fayaz Wani and Il-Seok Jeong and Haekwan Jeon and Jaesun Kim and SuDong Park and Eun-Ae Choi and Seung Zeon Han and Seungwu Han and Byungki Ryu},
howpublished = {arXiv},
year = {2026},
month = jul,
doi = {10.48550/arxiv.2606.09023},
eprint = {2606.09023},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2606.09023},
}
RIS
TY - UNPB
TI - Precipitate phase selection and grain boundary morphology in Cu-Ni-Si-Mn alloys: A machine-learning interatomic potential study
AU - Aadil Fayaz Wani
AU - Il-Seok Jeong
AU - Haekwan Jeon
AU - Jaesun Kim
AU - SuDong Park
AU - Eun-Ae Choi
AU - Seung Zeon Han
AU - Seungwu Han
AU - Byungki Ryu
PY - 2026
DA - 2026/07/20
PB - arXiv
DO - 10.48550/arxiv.2606.09023
UR - https://arxiv.org/abs/2606.09023
AB - Alloys inevitably contain interphase boundaries, whose energetics govern nucleation processes and precipitate morphology. In Cu-Ni-Si alloys, Mn addition markedly changes grain boundary (GB) precipitation behavior. While GB precipitation of stable Ni_2Si in Mn-free alloys is associated with degraded mechanical properties, Mn addition instead promotes film-shaped Mn_6Ni_16Si_7 (G-phase) precipitation, which is correlated improved mechanical properties. However, the atomic origin of the contrasting GB phase selection and morphology remains unclear. Here we perform machine-learning interatomic potential (MLIP) calculations to investigate the effect of interphase-boundary atomic structure on GB precipitates in Cu-Ni-Si alloys with and without Mn. The MLIP calculations reliably reproduce DFT-level energetics for interfacial bonding and microstructural configurations, and further predict that Mn addition favors GB precipitation of Mn_6Ni_16Si_7 rather than Ni_2Si. Experimentally, Mn-free alloys are observed to exhibit irregularly-shaped Ni_2Si precipitates with open-boundary-like Cu/Ni_2Si interfaces, whereas Mn-added alloys exhibit film-like G-phase at GBs. Large-scale atomistic interface calculations reveal that the coherent interface structure between Cu and Ni_2Si favors the formation of plate-like strained Ni_2Si precipitates in the matrix. Upon coarsening and stress release, an out-of-phase coherent-like interface can form at GBs, generating a local repulsive region that gives rise to surface-like open-boundary structures and explains the irregular morphology of GB stable Ni_2Si precipitates. In contrast, Cu/Mn_6Ni_16Si_7 interfaces remain predominantly incoherent with moderate boundary energies and no pronounced repulsive regime, thereby stabilizing continuous interfacial contact and explaining film-shaped GB precipitation.
ER -