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

Self-propagating high-temperature synthesis (SHS) with reduction process was used to fabricate TiB2 powder from TiO2-B2O3-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 5.8x10(-6) degreesC(-1) at 20-1000 degreesC, which was close to that of the traditional anthracite block cathode (4x10(-6) degreesC(-1)); the electrical resistivity was 8 mu Omega (.)m at 900 degreesC when the content 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.

碳纤维表面处理对铝电解用硼化钛阴极涂层性能的影响

硼化钛阴极涂层是铝电解用可润湿性阴极材料中的一种 ,具有优良的抗钠渗透性和对铝液润湿性 ,可以有效地延长铝电解槽寿命。碳纤维是硼化钛涂层材料的增强剂之一 ,对硼化钛阴极涂层的性能影响很大。本文研究了不同工艺的液相碳纤维表面氧化处理法对硼化钛阴极涂层抗拉强度和粘接强度的影响。采用FTIR检测碳纤维处理后表面含氧基团的变化 ,寻找影响硼化钛阴极涂层性能的原因 ,从而达到最有效地提高TiB2 阴极涂层抗拉强度和粘接强度的目的。结果表明 ,采用工艺 (1) (10 %HNO3,80℃、恒温 5min ,超声波、5min)对碳纤维进行表面处理最合理 ,处理后碳纤维表面含氧基团的含量最高 ,用其制备硼化钛阴极涂层的抗拉强度。