{
  "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 Ni$_2$Si in Mn-free alloys is associated with degraded mechanical properties, Mn addition instead promotes film-shaped Mn$_6$Ni$_{16}$Si$_7$ (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$_6$Ni$_{16}$Si$_7$ rather than Ni$_2$Si. Experimentally, Mn-free alloys are observed to exhibit irregularly-shaped Ni$_2$Si precipitates with open-boundary-like Cu/Ni$_2$Si 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$_2$Si favors the formation of plate-like strained Ni$_2$Si 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$_2$Si precipitates. In contrast, Cu/Mn$_6$Ni$_{16}$Si$_7$ interfaces remain predominantly incoherent with moderate boundary energies and no pronounced repulsive regime, thereby stabilizing continuous interfacial contact and explaining film-shaped GB precipitation.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": "Journal reference: Materials & Design 271, 117173 (2026)",
  "arxiv": "2606.09023",
  "author_total": 9,
  "authors": [
    {
      "name": "Aadil Fayaz Wani"
    },
    {
      "name": "Il-Seok Jeong"
    },
    {
      "name": "Haekwan Jeon"
    },
    {
      "name": "Jaesun Kim"
    },
    {
      "name": "SuDong Park"
    },
    {
      "name": "Eun-Ae Choi"
    },
    {
      "name": "Seung Zeon Han"
    },
    {
      "name": "Seungwu Han"
    },
    {
      "name": "Byungki Ryu"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/dx3c9g49gqm3w.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2606.09023",
  "fulltext_url": null,
  "id": "dx3c9g49gqm3w",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2606.09023",
  "language": null,
  "licence": "LicenseRef-arXiv-nonexclusive-1.0",
  "licence_label": "arXiv licence",
  "licence_source": "article",
  "licence_url": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "cond-mat.mtrl-sci"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2606.09023",
  "pmcid": null,
  "pmid": null,
  "published": "2026-07-20",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/dx3c9g49gqm3w.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:34:04Z",
      "native_id": "2606.09023",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2606.09023"
    }
  ],
  "subjects": [
    {
      "field": "physics",
      "origin": "arxiv:cond-mat.mtrl-sci",
      "subfield": "condensed-matter"
    }
  ],
  "title": "Precipitate phase selection and grain boundary morphology in Cu-Ni-Si-Mn alloys: A machine-learning interatomic potential study",
  "title_text": "Precipitate phase selection and grain boundary morphology in Cu-Ni-Si-Mn alloys: A machine-learning interatomic potential study",
  "type": "preprint",
  "updated_at": "2026-10-30T12:34:04Z",
  "url": "https://research.draconitic.com/paper/dx3c9g49gqm3w",
  "venue": "arXiv",
  "versions": [
    {
      "doi": "10.1016/j.matdes.2026.117173",
      "pid": null,
      "relation": "published-as",
      "title": null,
      "venue": null
    }
  ]
}