Minimum TiB2 Content in a Composite Cathode Wetted with Aluminum

Abstract

The minimum content of functional component (titanium borideTiB₂) in cathodic refractory material that provides wetting with molten aluminum is substantiated. It is established that total cathode wetting with aluminum is observed with some minimum content of TiB₂ in a powder composite (16 – 18 vol.%), when according to occurrence theory there is formation of an “infinite cluster”, i.e., a bonded percolation network of titanium boride particles. The volume of wetted composite containing a fixed amount (for example, 1 kg) of TiB₂ does not depend on its phase composition and porosity, but is determined by the diboride volume content. A TiB₂ content in the range 18 – 20 vol.% should be considered the optimum that creates reliable continuous wetting of a composite surface.