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 deg ) 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.