Colloidal Alumina-bonded TiB_2 Coating on Cathode Carbon Blocks in Aluminum Cells

摘要

Self-propagatipg high-temperature synthesis (SHS) with reduction process was used to fabricate TiB2 powder from TiO2-B2O2-Mg system. The colloidal alumina-bonded TiB2 paste was prepared and coated on the cathode carbon blocks. Various properties of the baked paste such as the corrosive resistance, thermal expansion and wettability were tested. Experimental results showed that the colloidal alumina-bonded TiB2 coating could be well wetted by liquid aluminum, and the thermal expansion coefficient of the coated material was 5.8×10-6℃-1 at 20-1000℃, which was close to that of the traditional anthracite block cathode (4×10-6℃-1); the electfical resistivity was 8 μΩ· m at 900℃ when the com- tent of alumina in the coated material was about 9% in mass fraction. In addition, some other good results such as sodium resistance were also reported.