MICROSTRUCTURAL EVOLUTION DURING COMBUSTION SYNTHESIS OF TiC-Fe CERMET
(State Key Laboratoryfor Mechanical Behavior of Materials,Xi′an Jiaotong University, Xi′an 710049, P. R. China)
Abstract: (Ti+C)+30% Fe powder mixture was used for a combustion front quenching test, and the quenched sample was analysed by scanning electron microscope (SEM) and energy dispersive X-ray (EDX) analysis to study the microstructural evolution during the combustion synthesis, meanwhile, the combustion temperature was measured. The results showed that the reaction of Ti+C takes place in Ti and Fe particles, respectively, and it is earlier in the Ti particle than that in the Fe particle. The reaction in the Ti particle can be described with a ternary-reaction-diffusion model, while the reaction in the Fe particle can be described with a solution-precipitation model. The molten Ti and Fe particles fuse together subsequently accelerating the formation of the final product, TiC particles andα-Fe binder.
Key words: microstructural evolution TiC-Fe cermet combustion synthesis