ABSTRACT NiCrAlY/Al2O3–20 wt-%TiO2 gradient coating on Cu–Be substrate was fabricated by atmospheric plasma spraying method. Effect of the phase composition and the microstructure of gradient coating on thermal shock behaviours were investigated by using the X-ray diffraction, scanning electron microscopy and energy dispersive spectrometry. The gradient coating shows a typical lamellar structure with a uniform thickness and good interface. The microhardness of gradient coating was 875 HV compared to the substrate of 199 HV. The thermal shock failure of gradient coating took place after 467 and 37 cycles at 400 and 600°C, respectively. The spallation boundaries of gradient coating with a step structure could be divided into three regions: coating spallation region (I), oxidation region (II) and coating region (III). The mechanism of thermal shock failure was discussed.

中文翻译：

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大气等离子喷涂NiCrAlY/Al2O3–20%TiO2梯度涂层在Cu-Be合金上的热冲击行为

摘要 NiCrAlY/Al2O3-20 wt-%TiO2 梯度涂层在Cu-Be 基体上是通过大气等离子喷涂法制备的。采用X射线衍射、扫描电子显微镜和能谱仪研究了梯度涂层的相组成和微观结构对热冲击行为的影响。梯度涂层显示出典型的层状结构，具有均匀的厚度和良好的界面。梯度涂层的显微硬度为 875 HV，而基材为 199 HV。梯度涂层的热冲击失效分别在 400 和 600°C 下循环 467 次和 37 次后发生。具有阶梯结构的梯度涂层的剥落边界可分为三个区域：涂层剥落区（I）、氧化区（II）和涂层区（III）。