共查询到18条相似文献,搜索用时 78 毫秒
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热障涂层研究的历史与现状 总被引:7,自引:1,他引:7
航空发动机性能的提高,对涂层技术提出了新的要求。综述了热障涂层系统的原理、应用及发展历史,分析了不同方法制造的底层,面层特点,讨论了影响热障涂层寿命的几个因素,并对破坏机理进行了阐述。 相似文献
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ZrO2陶瓷-金属梯度热障涂层的显微结构特征 总被引:4,自引:0,他引:4
利用等离子喷涂技术制备了ZrO2陶瓷和NiCrAl金属的梯度热障涂层,利用扫描电镜(SEM)、能谱仪(EDS)和电子探针(EPMA)研究了涂层的显微结构和化学成分分布特征。实验发现:梯度过渡层的显微结构明显不同,以金属为主要组分的过渡层主要为层状结构,以陶瓷为主要组分的过渡层层状特征不明显;过渡层化学元素分布不均匀,其中Zr和Mg分布特征相同,Zr与Ni分布位置互补,Cr、Al主要以氧化物形式位于晶粒边界处。 相似文献
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双陶瓷层热障涂层的隔热行为有限元模拟研究 总被引:1,自引:0,他引:1
基于热传导、热对流和热辐射理论建立了双陶瓷层热障涂层不透明和半透明物理模型,采用有限元ANSYS软件模拟了稳态温度场。结果表明双陶瓷层在不透明时,随总厚度或顶层厚度增加,顶层上表面温度近似线性增加,第2层和粘结层上表面温度近似线性降低。在陶瓷层半透明条件下,衰减系数对各层温度有一定影响。在衰减系数很大时,各层温度与不透明情况类似;在衰减系数较小时,顶层上表面温度略低于不透明时,第2层上表面温度略高于不透明时,粘结层上表面温度先快速后缓慢降低并保持不变,且远高于不透明时,界面反射能降低各层温度。 相似文献
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为了探讨激光重熔对等离子喷涂常规和纳米热障涂层(TBCs)的影响,采用等离子喷涂工艺在γ-TiAl合金表面制备了常规和纳米ZrO2-7%Y2O3TBCs,并对其进行激光重熔处理,研究了等离子喷涂常规TBCs、激光重熔-等离子喷涂常规TBCs、等离子喷涂纳米TBCs及激光重熔-等离子喷涂纳米TBCs 4种涂层在850℃下的抗热震性能。结果表明:4种TBCs热震失效次数依次为73,118,146,163次,相应的热震破坏形式分别为整体剥落、局部剥落、边角剥落和局部剥落;纳米结构有利于提高涂层的抗热震性能;激光重熔在一定程度上改善了等离子喷涂层的抗热震性能。 相似文献
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Daniel Nies Robert Pulz Steffen Glaubitz Monika Finn Birgit Rehmer Birgit Skrotzki 《Advanced Engineering Materials》2010,12(12):1224-1229
Thermal barrier coatings (TBCs) are used to increase the operating temperature of land‐, sea‐, or air‐based turbines. As failure of the coating may result in serious damage of the turbine, reliable estimation of the lifetime is essential. Most experiments to assess the lifetime or to determine parameters for simulations of the behavior of TBCs are done by burner‐rig‐tests, where the operating conditions are simulated by cyclic heating of the surface and cooling of the backside of a coated sample. In this work a possibility is presented to do comparable experiments by heating the surface with laser irradiation instead of a burner. For this purpose a Nd:YAG‐laser with a maximum output power of 1 kW and a wavelength of 1064 nm is used. The laser spot can be moved by integrated optics across the sample surface to achieve homogeneous heating of the coating. Cooling of the backside is done by air. The temperature of the sample surface is determined by an infrared‐camera which also enables the possibility to detect failures in the coating via thermography. Additionally, acoustic sensors attached to the sample holder are used to detect failures in the sample. The investigated ceramic material (yttria stabilized zirconia) has a very low absorption coefficient at the used laser wavelength. Therefore, a pre‐treatment of the samples was needed to increase the absorption coefficient to be able to heat up the samples. In this paper, the experimental setup and first experimental results are presented. 相似文献