Microstructural evolution of the titanium particles in the in-situ composition of TiC-Fe by the combustion synthesis

Coarse titanium powder was mixed with iron and carbon black powders, and the mixture was used for a combustion front quenching test. The quenched sample was analysed by scanning electron microscope and energy dispersive X-ray analyses to study the microstructural evolution of the titanium particles in the combustion synthesis. Also, the combustion temperature was measured, and the phase constituent of the combustion-synthesized product was inspected by X-ray diffraction. The results showed that the combustion reaction in Ti particles took place in the solid state and proceeded by the solid-state diffusion of C and Fe atoms into the Ti particles, forming in-situ composite of TiC-Fe. A ternary-reaction-diffusion model has been proposed to describe the microstructural evolution, and the use of the coarse Ti powder led to a residual phase FeTi. (C) 1999 Elsevier Science S.A. All rights reserved.