Cyclic oxidation resistance and self-healing properties of HfB2-doped glass composite coatings at 900 °C

Abstract

HfB2-doped glass coating exhibits superior cyclic antioxidative performance compared to pure glass coating. The HfB2 particles inhibit the precipitation of crystals with low thermal expansion coefficient, mitigating the risk of fish-scaling failure. In addition, the HfB2-doped glass composite coating, with high contents of amorphous phases, maintains its viscous flow properties even after multiple high temperature cyclic oxidations, which enables it to self-heal. Moreover, the oxidation product (B2O3) of HfB2 enhances network connectivity of the glass system, providing more unsaturated sites for the chemical bonding of the self-healing process.