Contact interaction, structure and geometry (relief) of interphase boundary in calcium fluoride–metal melt

Abstract

Processes of interaction in CaF₂––(Cu––20% (at.) Sn)––35% (at.) Ti and Sn–– 20,7% (at.) V alloys systems have been studied. The structure of contact boundary by methods of optical and electronic microscopy is investigated. Pure metals, which have low affinity to fluorine, the calcium fluoride surface, do not wet and with it do not interact. Alloys with chemically active metals (Ti, V and other) actively interact with fluorine, forming the new phases on a surface, for example, TiF₃, VF₃, however such alloys CaF₂ at high temperatures do not wet. This abnormal phenomenon takes place as TiF₃, VF₃ are gaseous compounds, which evaporate from interphase boundary. The special attention to studying of geometry (relief) of a surface of interphase boundary after wetting substrate by liquid metal is given. Explanations of the mechanism of formation, so-called “ledge” on substrate CaF₂ at temperatures 1270––1370 K are given.