Chemical Engineering Science, Vol.56, No.2, 683-692, 2001
Mechanistic investigation of electric field-activated self-propagating reactions: experimental and modeling studies
The mechanism of electric field-activated self-propagating reactions is investigated using the combustion Front quenching technique. In particular, previously published experimental results obtained through the field-activated combustion synthesis (FACS) of beta -SiC, TaC, Ti3Al and B4C-TiB2 are re-examined and compared. Pre-combustion and combustion stages involved during synthesis wave propagation are postulated for all systems. Subsequently, modeling results aimed at simulating the process where an electric field-activated, self-propagating reaction takes place are presented. In particular, a one-dimensional model of FAGS technique is developed to simulate the rapid quenching of the reaction during its progress as the applied field is turned off. A rate expression which accounts for the influence of temperature, particle size, compaction density, reactant stoichiometry, and inert content is included in the model.
Keywords:field-activated combustion synthesis;combustion front quenching;reaction mechanism;heterogeneous model;theoretical simulation