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 th e mixture was used for a combustion front quenching test. The quenched samp le 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 inspec ted by X-ray diffraction. The results showed that the combustion reaction i n Ti particles took place in the solid state and proceeded by the solid-sta te diffusion of C and Fe atoms into the Ti particles, forming in-situ compo site of TiC-Fe. A ternary-reaction-diffusion model has been proposed to des cribe the microstructural evolution, and the use of the coarse Ti powder le d to a residual phase FeTi. (C) 1999 Elsevier Science S.A. All rights reser ved.