Transition metal nitrides (TMNs) have gained widespread application in protecting structural components due to their high strength and hardness. However, TMNs still have the challenge of structural instability and mechanical deterioration caused by oxidation under harsh high temperature conditions. Herein, we present a strategy combining component regulation with high-entropy engineering to develop an advanced high-temperature Al-containing high-entropy nitrides (HENs) material. To prevent the phase decomposition of AlN within the (NbMoTaWAl)N, theoretical simulations were employed to determine a critical atomic percent of 25.0% Al for maintaining the stability of the high-entropy structure. Ensuing experimental synthesis creates three NbMoTaWAlN films with varying Al content: a high-entropy film with 0.0% Al (HEN), a high-entropy film with 21.2% Al (HEN-Al), and an amorphous transition metal nitride film with 30.2% Al (a-TMN-Al), validating key high-entropy engineering benchmarks. It is found that the unique HEN-Al film exhibits excellent oxidation resistance and high-temperature hardness, attributed to the uniform distribution of Al atoms in the robust high-entropy structure, which creates conditions for forming a dense and continuous Al2O3 barrier layer, effectively hindering the diffusion of oxygen into the film interior. This study provides new insights to develop a new generation of high-temperature protective materials.

中文翻译：

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组分调控和高熵工程增强保护膜的抗氧化和高温机械性能


过渡金属氮化物 （TMN） 因其高强度和硬度而在保护结构部件方面得到了广泛的应用。然而，TMNs 在恶劣的高温条件下仍然存在结构不稳定和氧化引起的机械劣化的挑战。在此，我们提出了一种将组件调节与高熵工程相结合的策略，以开发一种先进的高温含铝高熵氮化物 （HEN） 材料。为了防止 AlN 在 （NbMoTaWAl）N 内发生相分解，采用理论模拟来确定 25.0% Al 的临界原子百分比，以维持高熵结构的稳定性。随后的实验合成产生了三种具有不同 Al 含量的 NbMoTaWAlN 薄膜：一种是 0.0% Al （HEN） 的高熵薄膜，一种是 21.2% Al （HEN-Al） 的高熵薄膜，另一种是 30.2% Al （a-TMN-Al） 的无定形过渡金属氮化物薄膜，验证了关键的高熵工程基准。研究发现，独特的 HEN-Al 薄膜表现出优异的抗氧化性和高温硬度，这归因于 Al 原子在稳健的高熵结构中的均匀分布，这为形成致密且连续的 Al2O3 阻挡层创造了条件，有效阻碍了氧扩散到薄膜内部。本研究为开发新一代高温防护材料提供了新的思路。