Study on ZrSiO4-aluminosilicate glass coating with high infrared emissivity and anti-oxidation properties

- Melted aluminosilicate glass filled with surface cracks to form a dense coating.
- The coating shows high oxidation resistance performance at high temperature stage.
- High infrared emissivity is good for cooling down at high-temperature stage.

A multicomponent coating composed of ZrSiO4 and aluminosilicate glass was designed and prepared by slurry dipping and subsequent sintering on the surface of SiC substrate to improve the anti-oxidation ability of substrate. At appropriate temperature, the molten aluminosilicate glass carrying the stable ZrSiO4 particles will spread over the substrate's surface to form a dense and stable coating. Among them, the flowing aluminosilicate glass will fill the crack and micro-pores of ZrSiO4, which inform a dense coating. Glass phase and ceramic phase could inhibit the propagation of the cracks together. This coating shows high infrared emissivity at broad bands, reaching more than 0.93. Wonderfully, the coating was endowed high oxidation resistance performance at high temperature in the air, which was mainly attributed to the compact and stable structure of coating, coupled with the high thermal expansion coefficient.