A dual-layer ceramic coating based on silicon carbide and boron oxide on the graphite surface to establish high temperature oxidation resistance

In this work, to establish the oxidation resistance for graphite in the air atmosphere with temperatures ranging from 700 to 1000 °C, an innovative multi-component, dual-layer coating was developed. The coating consists of two layers with a total thickness of around 250 μm. The first layer was consisted of B₂O₃ with SiO₂ and ZnO, while the second layer included SiC with silicon as an additive. Through scanning electron microscopy (SEM) images and elemental maps, alongside heat treatment experiments at 1000 °C, which resulted in only a 6% weight loss, it was evident that the coating was effectively applied and performed exceptionally well. Moreover, cyclic heat treatment experiments confirmed the coating’s durability and thermal stress resistance, with minimal weight reduction results. Applying these coatings is uncomplicated, and the materials are readily available, ensuring cost-effectiveness.