Self-Propagating High-Temperature Synthesis of Titanium Carbide: An Educational Module using a Wooden Block Reactor

Resumo

Self-propagating high-temperature synthesis is an effective method for preparing refractory ceramic materials, especially carbides and borides as fine powders. The common perception that a pressurized stainless steel reactor is necessary for conducting the synthesis has, until now, excluded it from undergraduate laboratory courses. Our students performed this synthesis using a simple and inexpensive wooden block reactor to prepare TiC, using TiO₂, C and Mg as the reactants. The product at this stage is contaminated with Mg₂TiO₄ which forms through a side-reaction during this highly exothermic reaction. The factors that caused this provoked a stimulating class discussion and led to a method for recovering the TiC as a monophasic powder. The crude and purified product materials were characterized by powder X-ray diffraction. All in all, these aspects make this synthesis an ideal experiment for undergraduate laboratory in chemistry or materials science courses. Moreover, the skills and methods learned through this experiment ensure that students are better equipped to tackle the self-propagating high-temperature synthesis of more complex carbides and refractory ceramic materials in conventional reactors.