Synthesis of titanium carbide and TiC–SiO2 nanocomposite powder using rutile and Si by mechanically activated sintering

• Nanocrystalline TiC was synthesized from TiO2 by mechanically activated sintering.
• Ball milling process remarkably reduced TiC synthesis temperature.
• Si had a key role in the reduction of TiO2 by producing interphase compounds.
• TiO2 was reduced by the formation of titanium oxide of a lower degree of oxygen.

High-energy ball milling was applied with subsequent heat treatment for synthesizing nanoparticles of TiC powders by the carbothermic and carbosilisisothermic reduction of titanium oxide (rutile type). The milling procedure involved milling of TiO2/C and TiO2/Si/C powders at room temperature in an argon atmosphere. The progress of the mechanically induced solid state reaction was monitored using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The XRD results showed that TiC nanoparticles were duly synthesized in the TiO2/C system at 1700 °C in 60-h milled samples. In the non-milled samples, although heated at the same temperature, only a minor amount of a lower degree of titanium oxide (Ti3O5) was observed to form. Further, in other non-milled samples, but with Si initially present, despite heating to 1550 °C no TiC phase was detected. However, using Si as a reducing agent accompanied by graphite, after 60 h ball milling, only Si remained as a distinguishable crystalline phase. Further, heat treatment of activated powders by forming the interphase compounds (such as Ti3Si5 and Ti5Si3) remarkably decreased the synthesis temperature to 900 °C for the 60 h milled samples.

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