Rapid titanium carbide synthesis from titanium and graphite powders via ultrafast high-temperature sintering

• TiC compacts from Ti and graphite powders by ultrafast high-temperature sintering. • Self-propagating high-temperature synthesis reaction seen in early sintering stage. • Synthesis reaction occurs sooner by sintering above the melting temperature of Ti. • Single-phase TiC with mixed morphology obtained at all processing temperatures. • Plate-like TiC grown with elongated voids hinders further densification under UHS. Self-propagating high-temperature synthesis (SHS) is a combustion-based method that involves a self-heating chain reaction, which is effective for rapidly producing materials with high melting points. Herein, ultrafast high-temperature sintering (UHS) was leveraged to ignite the SHS of titanium carbide (TiC) from titanium and graphite powders, and the heat generation and microstructural evolution during the process were investigated. The exothermic heat generated during TiC synthesis was confirmed, demonstrating that SHS was initiated in the initial stage of UHS. The incubation time before SHS ignition decreased with an increase in the UHS temperature above the melting point of titanium. Scanning electron microscopy revealed that fine TiC grains formed during SHS, which became denser under continued UHS. Additionally, molten Ti spread over the graphite particles during SHS, which transformed into plate-like TiC grains with elongated voids between them under subsequent heating by UHS. This structural feature was found to hinder further densification.