In-situ synthesis and characterization of Fe – TiC based cermet produced from enhanced carbothermally reduced ilmenite

Abstract

In-situ synthesis of Fe-TiC based cermet by carbothermic reduction of South African ilmenite ore has been successfully achieved. This was carried out in an argon containing atmosphere in the temperature range of 850–1350 °C. Powder mixtures of ilmenite concentrate and graphite in molar ratio of 1:4 respectively, were milled for 2 h in a planetary mill (PM 100) to obtain intimate mixtures. The mixtures were then synthesized in a laboratory high temperature furnace at different reduction temperatures. The obtained X-ray diffraction results showed that Fe-TiC has been successfully formed at 1350 °C with 15 min holding time. The sequence of phase evolution showed a stepwise reduction of ilmenite FeTiO3 initially to form a mixture of Fe and TiO2, which was successively further reduced to Ti4O7, Ti3O5, Ti2O3 and finally TiC. Three or more major peaks were observed from thermo-analyses (TG, DTG and DTA) corresponding to the initial reduction of FeTiO3 at 983.3 °C, Ti4O7 at 1050 °C, Ti3O5 at 1200 °C and finally TiC at 1350 °C. Field Emission SEM coupled with elemental analysis showed a clear phase boundary between the metallic phase (Fe) and the ceramic –TiC in the cermet synthesized at 1350 °C.