Immersion Tests of TiB sub 2 -Based Materials for Aluminum Processing Applications.

摘要

This report summarizes molten Al immersion tests conducted under the Stable Cathode Development task to evaluate the microstructural behavior of TiB sub 2 -based materials. Four types of TiB sub 2 - based materials were evaluated before and after nonpolarized exposure to molten Al at temperatures encountered in Hall-Heroult cells. Three of the materials, TiB sub 2 -graphite (TiB sub 2 -G) composites, TiB sub 2 -aluminium nitride (AIN) composites, and high-purity TiB sub 2 sintered from halide plasma reduction powders, were chosen because they are prime candidates for Al-wetted cathode applications, based on a literature review (Schilling, Hagen, and Hart 1987) and previous experimental research at PNL (Hart et at. 1987). Ceramic fiber mesh coated with chemical-vapor-infiltrated TiB sub 2 was also evaluated, based on the expected wear resistance of the high-purity TiB sub 2 coatings and the possibility of designing advanced cells with complex cathode shapes that are not possible attack mechanisms that are related to chemical reactions between molten Al and cathode constituents. (ERA citation 13:054318)