Effect of carbon on mechanically induced self-sustaining reactions (MSR) in TiO2–Al–C mixtures

•Carbon has a significant role in the initiation of MSR reaction in TiO2–Al–C mixtures.•TiC and Al2O3 were detected in the sample with a molar ratio of TiO2:Al:C = 3:4:3 after 5 h of milling.•Without carbon no reaction was observed even after 5 h of milling in the TiO2–Al system.

Mixtures of titanium dioxide, aluminium powder and activated carbon with different mass ratios were prepared and milled for different times. The amount of carbon used increased from 0% to 100% of that required for formation of TiC to study the effect of carbon on initiation of a self - sustaining mechanochemical reaction in TiO2-Al-C mixtures. The XRD results indicated that by increasing the fraction of carbon the products were changed from Al3Ti and Al2O3 to include increasing amounts of TiC and Al2O3. Results also indicated that the reaction could be initiated during milling but only for the samples with high carbon. In the sample with a molar ratio of TiO2:Al:C = 3:4:3, the reaction between raw materials was complete within 5 h of milling time when only TiC and Al2O3 were detected.