Cathodic Behavior of Titanium Diboride in Aluminum Electrolysis

Abstract

The results of a laboratory investigation concerning the cathodic behavior of TiB2-based materials in aluminum electrolysis are presented and discussed. X-ray microanalysis reveals sodium penetration, the extent of which is in agreement with electrochemical predictions considering the codeposition of sodium with the aluminum at the cathode.The application to cathode design of conductive materials wetted by liquid aluminum [e.g., titanium diboride

Electrodeposited TiB2 on graphite as wettable cathode for Al production

“…7 However, in contact with molten Al, additives and remaining oxides are dissolved, leading to the formation of secondary phases at the TiB 2 grain boundaries. [11][12][13][14] These may lead to crack propagation and contamination of Al, along with failure of the TiB 2 . Alternatively, coating methods such as chemical vapor deposition 15,16 or thermal spray methods [17][18][19] are potentially interesting since less TiB 2 material is used.…”

“…The use of sintering aid additives such as Cr, Ni and Fe allows the pressureless sintering of TiB 2 at relatively low temperature (~1500°C), preventing exaggerated grain growth detrimental for its mechanical properties 7 . However, in contact with molten Al, additives and remaining oxides are dissolved, leading to the formation of secondary phases at the TiB 2 grain boundaries 11‐14 . These may lead to crack propagation and contamination of Al, along with failure of the TiB 2 .…”