Bulk Resistivity of Materials in the Si

The formation of silicon carbide (SiC) and the energy distribution in the furnace are two important parameters in evaluating furnace operations. The energy distribution is determined by the resistivity of the materials in the furnace. This work aims to investigate the bulk resistivity of materials in the silicon (Si) furnace using both partially transformed carbon materials and raw charge mixes. In this study, the impact of temperature, SiC and Si content, and the addition of insulating charge materials are investigated up to 1600 °C using carbon materials as a base. The materials were treated under similar conditions to the industrial furnace. The resistivity of the carbon materials was between 7 and 17 mΩ m at 1600 °C, where the char and coal were generally more conductive than the charcoal. The resistivity of partially transformed materials increased with conversion to SiC, and coal with a higher SiC content than 60% had an average resistivity at 1600 °C of around 30 mΩ m. The resistivity then began to decrease as elemental Si formed in the pores. Up to 36%, the amount of Si did not affect the measured resistivity, but its presence likely causes a slight decrease. Computed tomography (CT) scans show that the SiC material is not visibly changing or transforming in the crucible during measurement.