Metastable (Ti,Al)N thin films with face-centered cubic (fcc) structure are widely applied to protect tools and components used in the machining industry for their high hardness and exceptional thermal stability. Alloying is a simple but powerful strategy to further improve the performance of (Ti,Al)N thin films. Here, the combination of experiments and calculations allowed us to further improve the mechanical properties, thermal stability, and oxidation resistance of arc-evaporated (Ti,Al)N films through the addition of Nb and Ta. The developed TiAlNbN, TiAlNbN, TiAlTaN, and TiAlTaN thin films show a single-phase fcc structure like TiAlN. While the hardness () of as-deposited (Ti,Al,Nb)N thin films is similar to that of TiAlN (30.1 ± 0.4 GPa), it increases to 33.2 ± 0.7 and 34.1 ± 1.1 GPa by alloying with 7 and 16 at.% Ta (metal fraction), respectively. Both alloying elements allow to retard the spinodal decomposition of (Ti,Al)N, as suggested by X-ray diffraction of vacuum-annealed samples. The (Ti,Al)N and (Ti,Al,Nb)N samples exhibit the onset of wurtzite (w-) AlN formation at ~1050 °C, which is postponed to ~1200 °C for the (Ti,Al,Ta)N thin films. calculations suggest that age hardening of (Ti,Al)N is improved by Nb and Ta, with Nb being more effective than Ta. This is verified by experiments showing that TiAlNbN (TiAlNbN) and TiAlTaN (TiAlTaN) experience an increase of to 34.7 ± 0.5 GPa (36.7 ± 0.7 GPa) and 35.8 ± 1.0 GPa (37.0 ± 1.1 GPa) when annealed at 1000 °C, compared to the 32.4 ± 0.7 GPa of TiAlN annealed at 900 °C. The relative increase is thus higher for (Ti,Al,Nb)N than for (Ti,Al,Ta)N. Furthermore, Nb and Ta also improve the oxidation resistance of (Ti,Al)N with Ta being more effective than Nb. Based on these results we can conclude that both Nb and Ta elements improve hardness, thermal stability, and oxidation resistance of (Ti,Al)N, with Nb providing more relative hardness gain but Ta providing higher absolute values.

中文翻译：

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Ab initio 支持开发具有更高热稳定性的铌合金和钽合金 (Ti,Al)N 薄膜

具有面心立方 (fcc) 结构的亚稳态 (Ti,Al)N 薄膜因其高硬度和出色的热稳定性而被广泛应用于保护机械加工行业中使用的工具和部件。合金化是一种简单但有效的策略，可进一步提高 (Ti,Al)N 薄膜的性能。在这里，实验和计算的结合使我们能够通过添加 Nb 和 Ta 进一步提高电弧蒸发 (Ti,Al)N 薄膜的机械性能、热稳定性和抗氧化性。所开发的TiAlNbN、TiAlNbN、TiAlTaN和TiAlTaN薄膜显示出与TiAlN类似的单相fcc结构。虽然沉积态 (Ti,Al,Nb)N 薄膜的硬度 () 与 TiAlN 的硬度 (30.1 ± 0.4 GPa) 相似，但通过在 7 和 16 合金化，其硬度增加到 33.2 ± 0.7 和 34.1 ± 1.1 GPa。 .% Ta（金属分数），分别。正如真空退火样品的 X 射线衍射表明的那样，这两种合金元素都可以延迟 (Ti,Al)N 的旋节线分解。 (Ti,Al)N 和 (Ti,Al,Nb)N 样品在约 1050 °C 时开始形成纤锌矿 (w-) AlN，而 (Ti,Al,Ta) 样品则推迟到约 1200 °C )N 薄膜。计算表明，Nb 和 Ta 可以改善 (Ti,Al)N 的时效硬化，其中 Nb 比 Ta 更有效。实验验证了这一点，结果表明，与在 1000 °C 退火时相比，TiAlNbN (TiAlNbN) 和 TiAlTaN (TiAlTaN) 在 1000 °C 退火时的强度分别增加至 34.7 ± 0.5 GPa (36.7 ± 0.7 GPa) 和 35.8 ± 1.0 GPa (37.0 ± 1.1 GPa)到 900 °C 退火的 TiAlN 的 32.4 ± 0.7 GPa。因此，(Ti,Al,Nb)N 的相对增加高于 (Ti,Al,Ta)N。此外，Nb和Ta还可以提高(Ti,Al)N的抗氧化性，其中Ta比Nb更有效。基于这些结果，我们可以得出结论，Nb 和 Ta 元素均可提高 (Ti,Al)N 的硬度、热稳定性和抗氧化性，其中 Nb 提供更多的相对硬度增益，而 Ta 提供更高的绝对值。