Microstructure at the interface of titanium carbide and nickel aluminides

Microstructure at the interface of titanium carbide and nickel aluminides in the samples obtained by infiltration of molten Ni₃Al alloy has studied by a scanning electron microscopy (SEM) and an analytical transmission electron microscopy (ATEM) with an energy dispersive spectrometer (EDS). It is found that the morphology at the interfaces between hard phase skeleton of TiC_0.7 and metallic phases depends on the ratio of Ti/C in carbide. Some periodic zigzag fringes are observed at a smooth interface between metallic phase and carbides in the sample of Ni₃Al/TiC_0.7. The results of analysis using EDS show that Ti in TiC_0.7 carbide is easier than that in TiC_0.9 to dissolve into the molten alloy during solid-liquid reaction. The formation of this periodic zigzag fringe,which may be a growth zone of a new Ti-Ni-Al phase,in the interface of TiC^0.7/Ni₃Al would occur during the initial stage of solidification.