Open AccessCorrosion and oxidation of silicon carbide on the nitride bond in the side lining of aluminum electrolysis cells
Author(s) -
A. L. Yurkov,
А. П. Малахо,
В. В. Авдеев
Publication year - 2019
Publication title -
novye ogneupory
Language(s) - English
Resource type - Journals
ISSN - 1683-4518
DOI - 10.17073/1683-4518-2019-1-43-48
Subject(s) - corrosion , electrolyte , materials science , cryolite , silicon carbide , electrolysis , oxide , nitride , carbide , metallurgy , aluminium , silicon , silicon monoxide , inorganic chemistry , chemical engineering , composite material , chemistry , electrode , layer (electronics) , engineering
The main question for understanding the corrosion of silicon carbide on the nitride-silicon bond onboard linings is whether corrosion of Si 3 N 4 ‒SiC material with gases (and, in particular, oxidation) is preceded by corrosion by molten electrolyte, or corrosion by molten electrolyte plays its own role in material degradation during service. It is more likely that the reactions of SiC and Si 3 N 4 with cryolite melt pass through a preoxidation stage. Calculations show that most of the possible reactions of SiC and Si 3 N 4 with oxygen and carbon monoxide and carbon dioxide have a positive volumetric effect, which reduces the porosity of the material, but may cause cracks in it. The resulting silicon oxide is dissolved in the electrolyte melt, and can also react with electrolyte components in the gas phase. Ill. 6. Ref. 24. Tab. 2.