An abradable and anti-corrosive CuAl-Ni/C seal coating for aero-engine

Abradable seal coatings (ASCs) can be deemed as the critical component for the aircraft turbine engines, which can enhance the aero-engine efficiency and protect the blades. However, high-performance and long-duration operation of ASCs is still limited by both corrosion and mechanical degradation. Herein, we develop a CuAl-Ni/C ASC by thermal spraying for the aero-engine, which synergistically enhances mechanical properties and improves corrosion resistance. Morphology characterizations firstly demonstrate a complete three-layer structure and excellent interlayer combination of the as-sprayed CuAl-Ni/C coating. Based on the service performance evaluation, the coating not only presents a low weight loss of 0.327 mg cm−2 by erosion tests and a low consumed energy of 0.325 J by abrasion tests, but also allows a high oxidate resistance at 500 °C, indicating an excellent combination of high erosion resistance, sufficient abradability and anti-oxidation at high temperature. In addition, the coating features a superior anti-corrosive performance and enhanced mechanical properties after 500 h spray tests. Finally, DFT calculation and MD simulations reveal the superior corrosion resistance of the coating originated from the existence of intermetallic compound AlCu4, effectively suppressing corrosion of the coating. This study not only provides an effective strategy for delicate design of the high-performance ASCs at the high-temperature and corrosive marine environment, but also elucidates the inherent essence for the anti-corrosive behavior of CuAl-Ni/C ASC from atomic level, which offers a novel insight for study on corrosion of multiphase system.