Critical Conditions for Gasless Combustion Wave Propagation Across an Air Gap

The transition of a combustion wave in a self-propagating high-temperature synthesis (SHS) process across an air gap is investigated both experimentally and theoretically. Our study is carried out using cylindrical samples fabricated from powder mixtures of different compositions. Critical air gap widths are determined, at which the combustion wave can still transfer from one sample to another. Based on the developed mathematical model, the effective emissivity of the end surface of the burning sample is calculated for different mixture parameters. The results are consistent with the experimental data.