ABSTRACT In the current work, the mono-layer Al–Cr–Ni coating and the bi-layer Al–Ni/Al–Cr coating were successfully synthesised on the Ti–6Al–4V alloy substrate by mechanical alloying. The effect of powder ratio was studied. The microstructure and phase composition of the two coatings were investigated. The mono-layer coating was composed of grey black composite structure. In the bi-layer coating, the Al–Cr outer layer exhibited a composite structure similar to the Al–Cr–Ni coating. The results showed the approximate thickness of Al–Cr–Ni coating was 140 μm, while that of bi-layer coating was more than 200 μm. Both coatings were well bonded to the substrate. After 850°C of cyclic oxidation for 100 h, cracks only occurred at the interface of the mono-layer coating, and no significant defects were found at the two interfaces of the bi-layer coating. The cyclic oxidation test results showed the bi-layer coatings exhibited more excellent oxidation resistance.

中文翻译：

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单层和双层涂层的高温氧化行为

摘要 在目前的工作中，通过机械合金化在 Ti-6Al-4V 合金基体上成功合成了单层 Al-Cr-Ni 涂层和双层 Al-Ni/Al-Cr 涂层。研究了粉比的影响。研究了两种涂层的微观结构和相组成。单层涂层由灰黑色复合结构组成。在双层涂层中，Al-Cr 外层表现出类似于 Al-Cr-Ni 涂层的复合结构。结果表明，Al-Cr-Ni 涂层的近似厚度为 140 μm，而双层涂层的厚度超过 200 μm。两种涂层都很好地结合到基材上。850℃循环氧化100h后，裂纹仅出现在单层涂层的界面，双层涂层的两个界面均未发现明显缺陷。