Corrosion Science 258 (2026) 113395

Prism-plane-textured Cr₂AlC MAX-Phase Coatings with Superior Resistance to Coupled Thermal–Salt–Steam Corrosion
Kaixuan Xu, Shenghao Zhou, Zhenyu Wang*, Xiaoyu Sun, Kaiwei Yang, Kaihang Wang, Aiying Wang, Peiling Ke*

Using synchronous pulse HiPIMS deposition technology, a Cr₂AlC MAX phase coating with a strongly (11-20) basal plane orientation was prepared. The coating's corrosion resistance and elemental diffusion mechanisms were investigated through simulated thermal-salt-steam environment corrosion tests at 600 °C for varying durations. Results indicate that the preferred (11-20) oriented coating exhibits significantly superior corrosion resistance compared to equiaxed grain coatings. After 5 hours of exposure to the corrosive environment, its corrosion film thickness was only one-third that of the equiaxed coating. This outstanding performance is attributed to two key mechanisms: (1) rapid and homogeneous Al diffusion along the oriented structure, enabling the early formation of a compact, amorphous Al₂O₃ surface scale; and (2) effective suppression of Cr₂AlC decomposition and Cr₇C₃ formation by maintaining local Al concentration. In stark contrast, the equiaxed coating exhibited porous oxide formation, deep aluminium depletion, and structural degradation due to non-uniform aluminium diffusion.

URL：https://doi.org/10.1016/j.corsci.2025.113395