High- and medium-entropy nitride coatings from the Cr–Hf–Mo–Ta–W–N system: Properties and high-temperature stability
| Autoři | |
|---|---|
| Rok publikování | 2026 |
| Druh | Recenzovaný odborný článek |
| Časopis / Zdroj | Journal of the European Ceramic Society |
| Fakulta / Pracoviště MU | |
| Citace | |
| www | https://www.sciencedirect.com/science/article/pii/S095522192600138X |
| Doi | https://doi.org/10.1016/j.jeurceramsoc.2026.118262 |
| Klíčová slova | Magnetron sputtering; High entropy ceramics; Refractory metals; Nitrides; Temperature stability |
| Přiložené soubory | |
| Popis | High- and medium-entropy nitride coatings from the Cr–Hf–Mo–Ta–W–N system were studied using ab initio calculations and experiments to clarify the role of entropy and individual elements in phase stability, microstructure, and high-temperature behaviour. Formation energy calculations indicated that nitrogen vacancies stabilise the cubic (fcc) phase, with hafnium and tantalum acting as strong stabilisers, while tungsten destabilises the lattice. Coatings were deposited by reactive magnetron sputtering at ~50 °C (AT) and ~580 °C (HT). All exhibited columnar fcc structures; high-temperature deposition produced denser coatings, lower nitrogen content, and larger crystallites, resulting in higher hardness and elastic modulus. Thermal stability was tested up to 1200 °C on Si and oxidation at 1400 °C on sapphire. AT coatings failed early, while most HT coatings endured. Nitrogen loss ?10 at.% at 1000 °C was critical for survival. TEM revealed tungsten segregation and HfO2 formation, while fcc nitride remained dominant. Ta enrichment proved essential for superior thermal and oxidation stability. |
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