The Study Of Improving Anti-erosion Of Clayey SiC

SiC is the quality refractory used in the aluminum smelting developed in recent years. The material does not make non-ferrous metals wet, having high thermal conductivity, good thermal shock resistance, anti-erosion and anti-corrosion of metal vapor. High production costs limit its rapid development. Refractory in the silicon carbide, clayey SiC has the most simple production process and the lowest price. However, due to the addition of clay, some performances of the clayey SiC deteriorate. It is applied in aluminums electromagnetic pump of the North University of China. Owing to the large open pores, molten aluminum molten aluminum will penetrate into it and become Al2O3. Clay will react with molten aluminum, causing material damaged. By imposing glaze layer on clayey SiC surface, preventing molten aluminum contacts with the material directly. Dense glaze layer makes molten aluminum un-infiltrate into the material and un-react with it.This paper discusses the natures of slurry glaze, firing temperature how to impact the quality of glaze. Make the erosion test in the high temperature furnace and aluminum electromagnetic pump, analyzing the mechanism of erosion of clay- silicon carbide imposed and un-imposed glaze with molten aluminum.The natures of the glaze skip, such as ingredients, suspended, density, mobility, impact glazing process and the quality of firing glaze largely. The more content of CMC in the glaze, the bigger viscosity of glaze skip. In the amount of 1.1wt%, glaze slurry has appropriate viscosity, suspension and stability, for glazing process on the clayey SiC products. Glaze slurry, density from 1.4 to 1.5g?cm-3, will be of good quality glaze. Any of the ingredients is too much or too little will deteriorate the quality of glaze, the formula on the 1st glaze having the best quality glaze. Firing system is the final and key process, through experiments, No.6 firing system is the best.Make the erosion test in the high-temperature furnace and liquid aluminum electromagnetic pump respectively. The paper measures apparent porosity and big pore size of clayey SiC products un-imposed and imposed glaze, the depth of erosion, using XRD, SEM methods analyze phase and microstructure of erosion sample, concluding the damage mechanism. The results follow as that: porosity and pore size was significantly reduced imposed glaze sample. Large pore size is reduced from 100-micron to 10 microns and porosity rate is from 24.4% to 8.7%; the samples imposed and un-imposed react with molten aluminum. SiO2 included in samples and glaze layer react with molten aluminum. Tested in the aluminum electromagnetic pump, a lot of molten aluminum infiltrate into the samples under pressure, causing the damage of it. If having not SiO2 in glaze layer, it will not be eroded swap. It will be able to prevent aluminum contact with clay directly, lowering the erosion of silicon carbide.