Effects of particle size of reactant on characteristics of combustion synthesis of TiC-Fe cermet

Four Ti-C-Fe powder mixtures, with a same molar ratio but a different particle size, were used for a combustion synthesis of TiC-Fe cermet to investigate effects of the particle size on the characteristics of the combustion synthesis. The results showed that the mixture with the finer Ti powder gave out a higher combustion temperature, a higher reaction velocity, a higher product density, a layer-shaped pore, and a greater size of TiC particles whether the Fe powder was finer or coarser. While in the case of the coarser Ti powder used, a small amount of residual phase remained in the product, and what is more interesting that the mixture with the finer Fe powder gave out a lower reaction velocity than that by the mixture with the coarser Fe powder. These effects were successfully explained with the previously proposed mechanisms of the combustion synthesis of TiC-Fe, and the mechanisms were proved to be valid thereby. (C) 2002 Kluwer Academic Publishers.