Wettability of some refractory materials by molten SiO2–MnO–TiO2–FeOx slag

The wettability of some refractory materials, including Mo, Pt, W, polycrystalline Al2O3, MgO, and graphite, by a molten 38.7 wt.% SiO2–44.3 wt.% MnO–11.4 wt.% TiO2–5.6 wt.% FeOx (x = 1 or 1.5) slag was investigated at temperatures between 1473 and 1673 K in an Ar atmosphere. The slag wets these materials quite well and the work of adhesion is in the range of 0.60–0.75 J m−2, except for graphite. A strong reaction between the slag and Al2O3 as well as MgO leads to small apparent contact angles (∼10 ± 2°) and good adherence. The wettability of the refractory metals depends not only on temperature but also on metal species. At 1473 K, the wettability is in the order of Pt > W > Mo. An increase in temperature considerably promotes the wettability of Mo and W while only mildly for Pt. The wettability and adhesion of graphite by the slag is poor. However, a temperature-dependent reaction leads to a considerable decrease in the contact angle as well as a foaming behavior of the sessile drop.