{
  "abstract": "Natural cellulose nanofibers (CNF) have emerged as alternatives to synthetic carbon nanofillers in ceramic matrix composites (CMC). They offer homogeneous dispersion and can graphitize in situ during pressure-assisted spark plasma sintering (SPS) into a 3D electrically percolating graphene-like network within a highly refined ceramic matrix. Unlike graphene, they are not prone to anisotropic alignment under pressure. However, translating this concept from pressure-assisted to pressureless SPS (pSPS) remains challenging. The absence of external pressure may limit stress-assisted in situ graphitization of CNF. Here, we investigate the effect of pSPS heating rate (5–750 °C/min) on densification, microstructural evolution, graphitization, and electrical properties in CNF-containing zirconia matrix. Raman spectroscopy confirmed graphitization of CNF within dense zirconia, irrespective of heating rate. The resulting graphitic phase acted as a diffusion barrier, slightly reducing density by 2-4% while refining the grain size from 200 to 155 nm. High heating rates promoted spatial organization of graphitized CNF into an intergranular, few-layer graphene-like network. This is attributed to the heating-rate-driven evolution of thermal von Mises stresses, from 23-100 MPa, which activate graphitization under pressureless sintering conditions. Consequently, electrical percolation was achieved at ≥100 °C/min, yielding DC conductivities of 5-15 S/m. These findings establish a critical link among transient thermal stress, in situ CNF graphitization, and electrical percolation, thereby providing a pressureless, rapid-sintering strategy for CMCs fabrication.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": null,
  "author_total": 8,
  "authors": [
    {
      "name": "Nikhil Bhootpur"
    },
    {
      "name": "Charles Manière"
    },
    {
      "name": "Sandra Drev"
    },
    {
      "name": "Marjeta Maček Kržmanc"
    },
    {
      "name": "Tadej Rojac"
    },
    {
      "name": "Aljaž Iveković"
    },
    {
      "name": "Bernd Wicklein"
    },
    {
      "name": "Andraž Kocjan"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/badz3k8bh4rsj.bib",
  "cited_by": 0,
  "doi": "10.1016/j.carbon.2026.122140",
  "fulltext_url": null,
  "id": "badz3k8bh4rsj",
  "issns": [
    "0008-6223"
  ],
  "landing_url": "https://hal.science/hal-05763191v1",
  "language": "en",
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "hal",
      "0.chim"
    ],
    [
      "hal",
      "1.chim.mate"
    ],
    [
      "openalex",
      "2503|Advanced ceramic materials synthesis"
    ]
  ],
  "openalex": "W7213943273",
  "pdf_url": "https://hal.science/hal-05763191/document",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-21",
  "publisher": "Elsevier",
  "ris": "https://research.draconitic.com/paper/badz3k8bh4rsj.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:40Z",
      "native_id": "hal-05763191",
      "source": "hal",
      "url": "https://hal.science/hal-05763191v1"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "hal:1.chim.mate",
      "subfield": "materials-polymers"
    }
  ],
  "title": "Rapid pressureless sintering of zirconia ceramics with percolative graphene-like networks",
  "title_text": "Rapid pressureless sintering of zirconia ceramics with percolative graphene-like networks",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:17:40Z",
  "url": "https://research.draconitic.com/paper/badz3k8bh4rsj",
  "venue": "Carbon",
  "versions": []
}