Wetting of TiC by non-reactive liquid metals Original Research Article

This paper is concerned with the wetting of TiC substrates by the non-reactive metals (Me=Cu, Ag, Au and Sn). The contact angle in the TiC/Sn and TiC/Cu systems reaches an equilibrium value slightly below 90° owing to the partial dissolution of titanium carbide in the molten metals. The intrinsic non-wetting behavior in the TiC/Ag system was confirmed. In the TiC/Au system, the non-wetting behavior is attributed to the strong metal–ceramic interaction that takes place at the interface and leads to the formation of a graphite layer. The addition of Fe or Ni increases the solubility of carbon in molten Au and decreases considerably the contact angle by preventing the formation of a graphite layer at the interface. Alloying non-reactive metals with Ti was done either by direct addition to the melt or by transfer from a sub-stoichiometric titanium carbide substrate. In both instances, the presence of Ti in the liquid metal, irrespective of its origin, improves wetting dramatically. The specific wetting behavior of the different Me–Ti alloys are well accounted for by the basic thermodynamic properties of the respective Me–Ti systems and of the titanium carbide phase.