Microstructure analyse of surface Ti-metallized graphite

The microstructure of surface Ti-metallized graphite was analyzed by XRD, SEM and EDX. The results show that the surface Ti-metallized graphite consists of interior layer (graphite), transition layer (620 μm), dense layer (40 μm) and exterior layer (Ti). XRD and EDX results show titanium carbide phase in the dense layer. SEM analyses confirm that good bonding exist between the interfaces. The short micro-structural crack between titanium and dense layer was found due to the large difference in the coefficient of thermal expansion. The crack can be eliminated by furnace cooling, instead of air cooling. It was not found between dense layer and transition layer because of titanium carbide deformed by the Ti-C reaction.