Combustion characteristics of SHS process of titanium nitride with TiN dilution

An experimental investigation of self-propagating high-temperature synthesis (SHS) of titanium nitride (TiN) was conducted using titanium compacts with TiN dilution in gaseous nitrogen. The objective of this study was to study the effect of diluent content on the combustion temperature, flame-front propagation velocity, and product morphology and composition. In addition, SHS characteristics, such as the melting and afterburning phenomena, associated with the titanium/nitrogen system were photographically presented. It was found that all undiluted titanium samples showed a considerable melting of titanium powders during the SHS process and thus led to a low degree of nitride conversion about 20–30%. The dilution of TiN in the reactant mixtures decreased the combustion temperature and reduced the melting of titanium. As a result, the TiN-diluted sample retained its porosity for the continuous filtration of nitrogen gas, hence leading to a prolonged afterburning stage where the nitridation continued. With the TiN dilution, the final product consisting of more than 90% of TiN was obtained in this study.