偏压对电弧离子镀CrAlN涂层微观结构及耐侵蚀性能的影响

Effect of bias voltages on the microstructure and erosion resistance of CrAlN coatings deposited by arc ion plating

摘要:

本文通过在TC11钛合金上利用电弧离子镀技术制备了铬铝氮(CrAlN)涂层。采用X射线衍射(XRD),扫描电子显微镜(SEM),能量色散X射线光谱(EDX),纳米压痕仪等对CrAlN涂层微观结构和机械性能(如硬度和弹性模量)的影响进行了分析。为了研究偏压对CrAlN涂层固体颗粒抗侵蚀性的影响,还进行了一系列固体颗粒侵蚀实验。结果发现,随着偏压从0V增加至200V,CrA1N涂层的择优生长取向逐渐从(200)转变为(111)晶面。硬度从15.1 GPa增加至接近20 GPa。同时,表面逐渐平整,大颗粒和针孔的数量减少,对CrAlN涂层的抗侵蚀性能均有一定影响。偏压150V时,CrAlN涂层获得最小侵蚀速率,其在30°时为0.032μm/ g,90°时为1.869μm/ g。这些结果表明,选择适当的偏压,CrAlN涂层能够获得更优异的固体颗粒侵蚀抗性。

Abstract:

In this work, the Chromium Aluminum Nitride (CrAlN) coatings were prepared on TC11 titanium alloy by arc ion plating. The effects of negative bias voltage on the micro-structure and mechanical properties, such as hardness and elastic modulus of the coatings were investigated by X-ray Diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX) and nano-indentation. A series of solid particle erosion experiments were also conducted to study the influence of bias voltages on the solid particle erosion resistance of CrAlN coatings. It has been found out that the preferred growth orientation of CrA1N coatings gradually varied from (200) to (111) crystal plane with the bias voltage changing from 0V to 200V. The hardness increased from 15.1 GPa to nearly 20 GPa. At the same time, the number of macro-particles and pinholes decreased with the surface gradually flattens, which improved the erosion resistance of the CrAlN coating. The CrAlN coating deposited at the bias voltage of 150V obtained minimum erosion rates which were 0.032 μm/g at 30° and 1.869μm/g at 90°, respectively. These results indicate that the CrAlN coating formed at an appropriate bias voltage can achieve an excellent solid particle erosion resistance.