Contact and Capillary Processes in Systems Promising for Brazing: Eutectic Melts of Niobium with Cobalt, Nickel, and Iron–Nonmetallic Al2O3–SiO2 and AlN–TiN Materials

The contact and capillary processes that occur in the interaction of eutectic Nb melts containing Co, Ni, and Fe with Al2O3–SiO2 and AlN–TiN solid substrates at 1400–1450°C in 10–3 Pa vacuum have been considered. The microstructure and phase composition of the interaction products in the contact area have been examined, and thermodynamic analysis of potential reactions has been performed. The effect of the solvent metal for niobium on these processes has been determined, and explanation for the different wettabilities of the same substrates has been proposed in terms of the properties (composition and structure) of the solid phase formed at the metal–ceramic interface. An example of the potential application of these melts for brazing nonmetallic materials is provided.