Abstract
Among NbC-ZrC coatings, an NbC coating modified with 30 mol.% ZrC achieves the best ablation-resistant property. It generates a liquid 10 μm-thick oxide film mainly composed of NbO and highly thermal-stable NbxZr1-xO2 phases. Furthermore, Nb4+ with a smaller ionic radius replaces Zr4+ and the transformation of NbO into Nb2O5 in air produces compressive stress stabilize the t-ZrO2 crystals. Significantly, a 1−2 μm-thick Nb-rich layer formed by reaction-diffusion between SiC and niobium suboxide (NbO2 and NbO) acts as a barrier to infiltrating oxygen, which provides interfacial anti-oxidation protection for the SiC transition layer during the oxyacetylene test.
Original language | English |
---|---|
Article number | 109541 |
Journal | Corrosion Science |
Volume | 188 |
DOIs | |
State | Published - 1 Aug 2021 |
Keywords
- Ablation resistance
- Carbon/carbon composites
- Crystal stabilisation
- High-temperature phase
- Interfacial diffusion
- NbC-ZrC coating