Mechanical and corrosion behavior of thick and soft DLC coatings
Mechanical and corrosion behavior of thick and soft DLC coatings
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DOI：
10.1016/j.surfcoat.2016.10.006
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发表时间：
2017-02-25
影响因子：
5.4
通讯作者：
Bruhl, S. P.
中科院分区：
文献类型：
--
作者：
Dalibon, E. L.;Escalada, L.;Bruhl, S. P.
DLC涂层具有化学惰性、低摩擦系数和良好的耐磨性。根据氢含量和sp(3)键的不同，它们可分为“软”膜或“硬”膜。本文对DLC厚膜的腐蚀行为、力学行为以及附着力进行了研究。用PACVD方法在渗氮奥氏体不锈钢(双层样品)和非渗氮奥氏体不锈钢(涂层样品)上沉积了含硅非晶氢碳膜。用能谱和拉曼光谱对薄膜进行了表征，用纳米压痕测定了薄膜的硬度，用OM和SEM分析了薄膜的微观结构。为了评估滑动磨损行为和摩擦，进行了销盘试验。采用ASTM G65-95干砂/橡胶轮试样机进行耐磨粒磨损试验。在水和沙的助熔剂中进行了冲蚀试验。通过盐雾试验和电化学测试对涂层的耐蚀性进行了评价。用划痕试验法测试粘附力。目的是系统地表征这些厚的DLC涂层中存在的与附着力、耐磨性和耐腐蚀性有关的缺陷。DLC涂层的厚度约为37µm，硬度为12 Gpa。涂层的摩擦系数较低，约为0.09。在磨料试验中，质量损失可以忽略不计，在冲蚀试验中，质量损失减少到30%。在腐蚀性能方面，盐雾试验仅在双相样品中表现良好。在使用STEPS的3.5%NaC l中的恒电位测试中，双面样品的电流密度在较高电位下增加。在薄膜附着力方面，这些样品的临界载荷也高于涂层样品。渗氮层是降低应力和提高附着力的良好界面，这与涂层中形成横向缺陷时腐蚀扩展速率的降低有关。2016(C)爱思唯尔B.V.保留所有权利。
The DLC coatings are chemically inert, have low friction coefficient and good wear resistance. Depending on H content and sp(3) bonds, they can be classified in "soft" or "hard" films. In this work, the corrosion and mechanical behavior, as well as the adhesion of thick DLC coatings are studied. The coatings, which are in fact silicon containing amorphous hydrogenated carbon films, were deposited by PACVD on nitrided austenitic stainless steel (duplex sample) and non-nitrided austenitic stainless steel (coated sample). The films were characterized by EDS and Raman spectroscopy, hardness was assessed by nanoindentation and microstructure was analysed by OM and SEM. To evaluate sliding wear behavior and friction, pin on disk tests were performed. The abrasive wear resistance was tested using the ASTM G65-95 Dry Sand/Rubber Wheel test. Erosion tests were conducted in water and sand flux. The corrosion resistance was evaluated by the Salt Spray Fog Test and electrochemical tests. The adhesion was tested using Scratch Test. The purpose was to systematically characterize the defects present in these thick DLC coatings relating them to adhesion, wear and corrosion resistance.The thickness of the DLC coating was about 37 mu m, and its hardness was 12 GPa. The coatings presented a low friction coefficient, about 0.09. In the abrasive tests, the mass loss was negligible and in erosion, experiments, the mass loss was reduced to 30%. Regarding the corrosion performance, the behavior in the Salt Spray Fog Test was good only in the duplex samples. In potentiostatic tests in 3.5% NaCl using steps, the current density increased at higher potentials for the duplex sample. Concerning the film adhesion, the critical load was also higher in theses samples than in the coated ones. The nitrided layer was a good interface for reducing the stresses and improving the adhesion, which is relevant for the decrease of the propagation rate of corrosion, when traversing defects are formed in the coating. 2016 (C) Elsevier B.V. All rights reserved.