Wettability of graphite by liquid aluminum under molten potassium halide fluxes

This study is a continuation of our previous work (Baumli et al. J Mater Sci 45:5177–5190, 2010) in which the wettability of graphite by liquid aluminum was studied under different molten chlorides containing K2TiF6 as function of the cation of the molten chloride. In the present paper, the same was studied as function of the anion in different potassium halides (fluxes). The fluxes consisted of different potassium halides (KX) + 10 wt% potassium hexafluoro-titanate (K2TiF6). The potassium halides studied were potassium iodide (KI), potassium chloride (KCl), and their equimolar mixture. For perfect wettability of graphite by liquid Al under different molten KX-10 wt% K2TiF6 systems at 800 °C, certain critical values of the salt:Al mass ratio should be achieved, the value of which increases from KI toward KCl. Comparing the present results with the results of our previous study, we found that the critical value of the salt:Al mass ratio increases with the cation size and decreases with the anion size of the salt.