Effect of Reactive Gas on the Wetting of Molten Iron–Carbon Alloy on Ceramic Substrates

Abstract

Wetting phenomena have occupied an important position in the field of high temperature metal processing for a long time. The difficulties encountered in the high temperature experiments—especially the separation of one effect from another—have frustrated efforts to achieve a full understanding of the dynamic wetting phenomena which are present in many metallurgical applications.
In this work the sessile drop method is used to study the effect of reactive gases on the dynamic wetting angle of a binary iron–carbon mixture on a ceramic substrate. The use of such a mixture enables the effect of dynamic gas–liquid reactions to be separated from the solid–liquid interactions. An experiment performed with SO₂, O₂ and N₂ gases at 1773 K proved that liquid surface tension can drop dramatically but the changes in wetting angle are only minor ones. It is also noted that the relative change in the volume of the droplet can give information about carbon boil and collapsing surface tension phenomena upon comparison with changes in the wetting angle of the droplet.