Combustion Synthesis of TiC–Fe Composites under the Action of an Electric Field

Abstract

Using thermal simulation equipment, the combustion synthesis process of the compact of 55wt%(Ti+C)–45wt%Fe was studied. The results show that the ignition temperature of Fe–Ti–C system can be decreased greatly under the action of electric field and great thermal density. Before heating up to 350°C, although there is no reaction takes place in the system, the microstructure of the system changes with the temperature; During heating from 350–470°C, a thermal explosion phenomenon appears. Especially in the earlier stage of the combustion reaction, the dominant reaction is the one synthesized TiC; As the temperature up to 670°C continuously, Ti_(s)+C_(s)=TiC_(s) reaction takes place accompanying with 2Fe_(s)+Ti_(s)=Fe₂Ti_(s), and the conversion degrees of these reactions are increasing with the temperature increasing gradually. However, a part of Fe₂Ti will be decompounded with the temperature increasing further, as a result, Ti_(s)+C_(s)=TiC_(s) will go on because of the addition Ti. Consequently, the synthesized product consist of Fe, TiC and a little of Fe₂Ti, and ultrafine TiC particles distribute in the Fe matrix uniformly.