A short temporal electrical impulse (duration of 30–150ms) was generated during the nitridation of mixtures of titanium and titanium nitride by a high temperature moving reaction front. The maximum voltage and current were generated in the combustion front region, in which the conversion of Ti to TiN was incomplete. The electric field (voltage up to 2V and current up to 60mA) decayed and vanished before the maximum combustion temperature was attained. The generation of an electric field during a rapid high-temperature nitridation is most probably due to the different diffusion velocities of charge carriers through the growing titanium nitride shell during the initial stage of the reaction. When the reactant mixture contained a high percentage of pure titanium (larger than 60wt%), partial melting led to irreproducibility in the amplitude and duration of the electrical signal.
Martirosyan, K. S., et al. “Electric-Field Generated by the Combustion of Titanium in Nitrogen.” Journal of Applied Physics, vol. 98, no. 5, American Institute of Physics, Sept. 2005, p. 054901, doi:10.1063/1.2007847.
Journal of Applied Physics