The Oxidation Resistance of the B4C-SiO2-Albite Coating Influenced by the In Situ Formation and Self-Healing Ability of Borosilicate Glass at 1173 K

The electrolytic aluminum industry is facing severe challenges, such as excessive carbon consumption, resulting in more cost and environmental pollution due to the oxidation of carbon anodes. The isothermal oxidation resistance of B4C-SiO2-Albite (BSA) composite coating influenced by the in situ formation behavior and self-healing ability of the borosilicate glass at 1173 K was investigated through XRD, TG-DSC, Raman, FTIR spectroscopy, and SEM/EDS in this paper. The results show that the composite coating with 20 wt% B4C has a relatively low mass gain rate of −0.082% after 24 h at 1173 K. It depends on the in situ formation of the amorphous borosilicate phase layer that can effectively protect the carbon anode from oxidation, which depends on the content of B4C. The amorphous borosilicate glass forms from the reaction between the SiO2 and the B2O3, from the oxidation of B4C during exposure. More B4C promotes the formation and volatilization of B2O3, which improves the viscosity and stability of the borosilicate glass by changing the glass network coupled with Na+ and Al3+ from Albite. It is a feasible strategy for designing durable coatings with appropriate B4C addition for high-temperature applications.