Wetting of porous graphite by Cu–Ti alloys at 1373 K

The isotherm wetting of porous graphite substrates by the molten Cu–Ti alloys with 1, 3, 4 and 5 at.% Ti was investigated at 1373 K in a flowing Ar atmosphere using a modified sessile drop method. The wettability increases with increasing Ti content in the alloy and the equilibrium contact angle reaches 6° for the Cu–5 at.% Ti alloy. The improvement of the wettability is due to the formation of a substoichiometric TiCx reaction layer at the interface. Increasing the Ti content makes the resultant TiCx phase more substoichiometric and thus significantly promotes the wettability.