Light Metals 2014 (Grandfield/Light) || N-SiC Side Lining - Variations of Materials Structure

摘要： The key process in fabrication of Nitride bonded silicon carbide side lining of reduction pots is the reaction between Nitrogen and Silicon. Silicon may react with Nitrogen in solid, liquid and gaseous phase. The reaction is strongly exothermal. Almost all N-SiC refractory materials of more or less big shapes have the gradients of porosity from middle to the edges. The reason for these gradients may be the overheating of the middle part of shapes, compared to near surface layers, due to the exothermal effect and consequent increased concentration of volatile Silicon. Volatile Silicon tends to move to areas of lower temperature and the gradients of porosity are 1-2 %, but sometimes it may reach 5-7%. The problems with side lining of reduction pots may be because of the design of the pots, due to the overheating of the bath, yet the structure of N-SiC materials might be also critical.