Abstract A ceria coating is electro-deposited on a chromium oxide forming Ni-based alloy to investigate the mechanisms of the reactive element effects. It is demonstrated that the ceria coating not only improves the oxidation resistance but also enhances the adherence between the oxide layer and the substrate alloy. The formation of iron oxide results in porous and cracked oxide layers on the bare sample. Oxide spallation starts to occur on the bare sample after exposure at 900 °C for 500 h. In contrast, a mixed iron-free oxide layer forms on the coated sample which is believed to enhance the oxidation resistance of the substrate. The change in oxidation mechanism of the coated sample from outward diffusion to inward diffusion is attributed to grain-boundary segregation of ceria particles. Furthermore, the formation of fine oxide grains on the coated sample improves the adhesion between the oxide layer and the matrix alloy. Schematic models of the oxidation mechanism are developed to interpret the oxidation behaviour of the bare and coated samples.

中文翻译：

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用于控制镍基合金 625 等温氧化行为的氧化铈涂层

摘要 在形成氧化铬的镍基合金上电沉积氧化铈涂层以研究活性元素效应的机制。结果表明，氧化铈涂层不仅提高了抗氧化性，而且增强了氧化层与基体合金之间的附着力。氧化铁的形成导致裸样品上的多孔和破裂的氧化层。在 900 °C 下暴露 500 小时后，裸样品上开始发生氧化物散裂。相反，在涂覆的样品上形成混合的无铁氧化物层，据信这增强了基材的抗氧化性。涂层样品的氧化机制从向外扩散到向内扩散的变化归因于氧化铈颗粒的晶界偏析。此外，在涂层样品上形成细小的氧化物颗粒提高了氧化物层和基体合金之间的附着力。开发了氧化机制的示意图模型来解释裸样品和涂层样品的氧化行为。