Quality Evaluation of Nitride bonded SiC Sidelining Materials. Historical Trends 1997-2022 Including Results and Development of Test Methods

The replacement of carbon-based sidelining materials by ceramics, mainly silicon nitride bonded silicon carbide, started in the late 80's. The ceramics have higher thermal conductivity and better oxidation- and chemical resistance. The latter opened up the opportunity of using thinner linings, which again enabled larger anodes and higher productivity due to amperage increase. Alton Tabereaux was a pioneer in establishing quality evaluation for this kind of material by TMS papers in 1993 and 1994. Inspired of his work and industrial needs; SINTEF, sponsored by the Norwegian aluminium industry, started to evaluate and develop laboratory scale test methods in 1994 to be able to rank commercial materials from the global market. In this paper, we summarize our findings regarding material parameters and test methods during the last 25 years. Important information for suppliers as well as users of these types of lining materials are given.