Effect of WB on oxidation behavior and microstructure evolution of ZrB2-SiC coating. (15th July 2019) - Li, Chong
Highlights: ZrB2 -SiC-WB coating prepared by vacuum plasma spray was firstly reported and its oxidation behavior was studied. Appropriate amount of WB greatly improved the oxidation resistance of the coatings. WB was more stable and a better boron source compared with ZrB2 for promoting self-healing ability. The oxidation product of WB could increase liquid viscosity, limit O2 diffusion, stabilize B2 O3 and form WO3 -ZrO2 eutectic. Abstract: In this work, different contents (5, 10, 15 mol.%) of WB were introduced into ZrB2 -SiC coatings which were fabricated by vacuum plasma spray technique. The oxidation resistant property of the ZrB2 -SiC-WB ternary composite coatings was evaluated in static air at 1500 °C. The results showed that appropriate amount of WB addition significantly improved the oxidation resistance of ZrB2 -SiC coating, as proved by the reduced weight gain and increased thickness of the liquid layer. The influence of WB and its oxidation product WO3 were analyzed based on the microstructure changes and thermodynamic calculations in detail.