TA1表面制备Ni/Al涂层的反应扩渗及抗氧化行为

为了提高纯钛的高温抗氧化性能,采用电弧喷涂和等离子喷涂方法在纯钛表面制备Ni/Al涂层.对试件进行900 ℃×5 h热处理后,再进行900 ℃×40 h连续氧化实验,探索其高温抗氧化行为.结果表明,经过表面改性处理的Ni/Al涂层可以显著提高纯钛的高温抗氧化性.在热处理过程中Ni/Al涂层中的Al发生熔化扩散并与Ni和Ti形成以NiAl与TiAl₃相为主的扩散层.在氧化过程中Ni/Al涂层表面形成连续且致密的α-Al₂O₃,同时表面扩散层中的富铝相可为涂层表面提供充足的Al元素,进而对纯钛基体提供有效的高温抗氧化保护作用.

Reaction diffusion and oxidation resistance behavior of Ni/Al coating prepared on TA1 surface

In order to improve the high-temperature oxidation resistance of pure titanium, a Ni/Al composite coating was prepared on the surface of pure titanium with the arc spraying and plasma spraying methods. The specimens were subjected to the heat treatment at 900 ℃ for 5 h, and then were subjected to the continuous oxidation experiment at 900 ℃ for 40 h to explore the high temperature oxidation resistance. The results show that the modified surface Ni/Al coating can significantly improve the high temperature oxidation resistance of pure titanium. In the heat treatment process, the Al element in the Ni/Al coating melts and diffuses, and forms a diffusion layer mainly composed of NiAl and TiAl₃ phases with Ni and Ti elements. During the oxidation process, the surface of Ni/Al coating forms a continuous and dense α-Al₂O₃ layer. Meanwhile, the aluminum-rich phase in the surface diffusion layer provides sufficient Al element for the surface, and provides an effective high-temperature oxidation resistance for the pure titanium matrix.