Microstructures and high temperature oxidation behaviors of AlMo0.5NbTa0.5TiZr high entropy alloys coated by silicon pack cementation

In this study, we fabricated silicon coatings on AlMo0.5NbTa0.5TiZr refractory high entropy alloy using pack cementation for the first time. The growth kinetics of the coating layer were analyzed by considering coating temperature, time, amount of Si, and NaF. The growth coefficient constant and activation energy were deter-mined to be 96,823 mu m/h1/2 and 117 kJ/mol, respectively. Microstructural analysis revealed the formation of a protective layer of SiO2 on the specimen surface, which increased its oxidation resistance at 1300 degrees C. Comparing the uncoated and coated specimens provided insight into the potential use of AlMo0.5NbTa0.5TiZr for high-temperature applications.