Wetting of TiC by non-reactive liquid metals

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 90degrees 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. (C) 2002 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved.