Microstructure and properties of multicomponent silicide ceramic coatings on Ta substrate prepared by slurry sintering method.

High entropy silicide (Mo 0.2 Cr 0.2 Ta 0.2 Nb 0.2 W 0.2)Si 2 (named as MeSi 2) coating was successfully prepared on Ta substrate by slurry sintering method. Firstly, precursor powders were initially obtained through mechanical alloying of silicide powders. Then powder slurry was coated on Ta substrate, and then the samples were sintered. For comparison, TaSi 2 coating prepared by halide-activated pack cementation method was synthesized. Subsequently, the static oxidation resistance of both MeSi 2 coating and TaSi 2 coating was examined at 1200 °C, results revealing that the MeSi 2 coating demonstrates an effective protection time of more than 60 h. The protective effect and duration of the MeSi 2 coating on Ta substrate are significantly greater than that of TaSi 2 , indicating an improvement oxidation resistance due to the high entropy effect of the silicide coating. After oxidation, the coating evolved an outer SiO 2 layer, followed by MeSi 2 , Me 5 Si 3 , TaSi 2 , and Ta 5 Si 3 layers. As the oxidation progressed, MeSi 2 gradually transformed into Me 5 Si 3 , leading to a loss of the coating's antioxidant capacity. [ABSTRACT FROM AUTHOR]