Abstract: The wetting angle between the liquid Ni₃Al and the TiC solid matrix was measured by using a 2AP-LEITZ high temperature microscope at 1420℃ under a flowing
Ar gas atmosphere. The effect of Mo addition into Ni₃Al on the wettability of Ni₃Al-TiC and the effect mechanism were mainly discussed. The result shows
that, the wetting angle of Ni₃Al-TiC is as low as 17℃, indicating an ideal cermet system. When Mo is added, the wetting angle gains a further
decrease, lower than 11℃. It is considered that, a small amount of Mo diffuses into the boundary of TiC particles and forms solid solution. The substituted Ti
then reacts with Ni₃Al in-situ. Thus decreases the tensile stress on the solid-liquid interface of Ni₃Al-TiC, leading to a great improvement in the wettability between Ni₃Al and TiC.

Key words: Ni₃Al-TiC, Mo, wettability, effect mechanism