For the first time the wettability of LiF, NaF, SrF2, LaF3, CeF3, ScF3 by pure metals and CaF2, BaF2, MgF2 monocrystals and SrF2 by Ti-, Zr-, Hf-, V-, Nb-, Cr- containing alloys (up to 50-70 mass %) was studied. Ga, In, Sn, Pb, Al, Cu, Ag, Au do not wet the fluorides in the temperature range from the melting point up to 1523 K. It has been established the non-wetting of the fluorides at high temperature by Ti (Zr, Hf, V, Nb, Cr) - containing melts which have high chemical affinity to fluorine. The phenomenon of dewetting, i.e., the increase of contact angle with increase of temperature to more than 1373 K for Ti-containing alloys/fluorides and aluminium/fluorides is observed. The decrease of contact angles for aluminium/fluorides can be observed at the temperatures 973-1373 K (contact angles are equal 100 ), but at the further heating (1373-1423 K) the dewetting occurs and contact angles increase more than 130 deg. The moderate wettability for Ti (V)-containing alloys/fluorides can be observed at the temperatures of 973 - 1223 K, but at further heating the dewetting occurs, and contact angles increase to more than 90 deg. The critical transformation temperature from wetting to non-wetting is 1273 K. When the liquidus temperature of the alloys is high enough (more than 1373 K), the non-wetting behavior takes place. Hereby the wettability is absent. The temperature dependences of wetting can be arbitrarily divided into three regions: a region of wetting at 973 - 1223 K; a transition region from wetting to non-wetting at 1223- 1273 K; a region of non-wetting at more than 1373 K. The wetting will be more high and stable, if: - the Gibbs free energy of reaction is negative or has only small positive value; - a new solid compound is formed. Wettability of fluorides by titanium (vanadium)-containing alloys and aluminium depends, mainly, on the state of new intermediate phase (TiFx, VFx, AlFx). It allows to use the alkaline-earth fluorides as refractory materials for the manufacturing of crucibles, cups for the measurement of surface tension, and also for melting and casting of chemically active alloys with large contents of Ti, Zr, Hf. The only limitation to use of these materials is their rather low melting points (1536 - 1693 K). The surface tension and density values of titanium-copper and zirconium-copper alloys in a wide active component concentration interval (from 10 up to 70 at.%) were measured by the sessile drop method. The surface tension - concentration dependence for melts deviates positively from Zhychovitsky theoretical isotherm for ideal solutions. The compression of alloys is observed. The titanium-copper and zirconium-copper melts deviates negatively from Raoult's law.
