Cerium doping of Ti-Al-N coatings for excellent thermal stability and oxidation resistance
Cerium doping of Ti-Al-N coatings for excellent thermal stability and oxidation resistance
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DOI：
10.1016/j.surfcoat.2017.07.037
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发表时间：
2017-10-15
影响因子：
5.4
通讯作者：
Mayrhofer, P. H.
中科院分区：
文献类型：
--
作者：
Asanuma, H.;Polcik, P.;Mayrhofer, P. H.
Ti-Al-N薄膜由于其优异的热机械性能而被广泛应用。然而，该系统仍然是许多研究活动的主题，以进一步提高其抗氧化性和热稳定性。添加反应性元素，如铈，可以显着提高各种材料的抗氧化性。因此，我们详细地研究了Ce（2at.%合金化）对磁控溅射Ti（0.50Al（0.50）靶材的生长过程、组织结构、力学性能、热稳定性和抗氧化性能的影响用Ubias =-25，-50，-75，当使用www.example.com而不是Ti0.50Al0.50靶时，沉积速率显著地增加了类似于1.75（Ubias =-25V）至1.45（Ubias =-100V）的因子Ti0.49Al0.49Ce0.02。此外，所得单相面心立方Ti 0.43 Al 0.55 Ce 0.02 N的硬度也类似于35 GPa，高于Ti 0.42 Al 0.58 N的硬度类似于34 GPa，对于多晶Al 2 O 3和Ubias =-50 V的涂层。在Ti0.43Al0.55Ce0.02N内形成纤锌矿结构的AlN仅能在T-a = 1100 ℃下检测到，比Ti0.42Al0.58N高约200 ℃。由于过饱和立方相的亚稳分解，它们的峰值硬度类似于Ta = 900 ℃时的37.0 GPa，而对于Ti 0.42 Al 0.58 N，Ta = 800 ℃时的峰值硬度为34.6 GPa。此外，即使在950 ℃下暴露于环境空气3小时后，仍有> 50%的Ti0.43Al0.55Ce0.02N涂层是完整的（低于类似于1.2 μ m的薄氧化层），而Ti 0.42 Al 0.58 N已经完全氧化。根据我们的结果，我们可以得出结论，Ce掺杂改善了沉积特性和机械性能以及热稳定性（包括：Ti-Al-N具有优异的抗氧化性，可用作各种高要求应用的保护涂层。(C)2017爱思唯尔B. V.保留所有权利。
Ti-Al-N thin films are well established due to their outstanding thermo-mechanical properties. Nevertheless, this system is still a subject of many research activities to further enhance their oxidation resistance and thermal stability. The addition of reactive elements, such as Cerium, can significantly improve especially the oxidation resistance of various materials. Therefore, we study in detail the impact of Ce (2 at.% alloyed to powder metallurgically prepared Ti0.50Al0.50 targets) on growth processes, structure, mechanical properties, thermal stability, and oxidation resistance of magnetron sputtered Ti(1 - x - y)A(l)xCe(y)N coatings prepared with DC bias potentials of Ubias = - 25, - 50, - 75, and - 100 V. The deposition rate is significantly increased by a factor of similar to 1.75 (Ubias = - 25 V) to 1.45 (Ubias = - 100 V) when using Ti0.49Al0.49Ce0.02 instead of Ti0.50Al0.50 targets. Furthermore, also the hardness of the resulting single phase face centered cubic Ti0.43Al0.55Ce0.02N is with similar to 35 GPa above that of Ti0.42Al0.58N with similar to 34 GPa, for coatings on polycrystalline Al2O3 and Ubias = - 50 V.All temperature dependent characteristics of Ti0.42Al0.58N are improved significantly by the addition of Cerium. Wurtzite-structured AlN formation within Ti0.43Al0.55Ce0.02N can only be detected at T-a = 1100 degrees C, about 200 degrees C higher as for Ti0.42Al0.58N. Their peak-hardness, due to spinodal decomposition of the supersaturated cubic phase is similar to 37.0 GPa with Ta = 900 degrees C, as compared to 34.6 GPa with Ta = 800 degrees C for Ti0.42Al0.58N. Additionally, even after exposure to ambient air at 950 degrees C for 3 h, still > 50% of the Ti0.43Al0.55Ce0.02N coating is intact (below the similar to 1.2 mu m thin oxide scale), whereas Ti0.42Al0.58N is already fully oxidized.Based on our results we can conclude, that Ce-doping improves the deposition characteristics and mechanical properties as well as thermal stabilities (incl. oxidation resistance) of Ti-Al-N, to be used as protective coatings for a wide range of high-demanding applications. (C) 2017 Elsevier B.V. All rights reserved.