Results of investigation of the combustion of mixtures of ultrafine aluminum and boron powders (the oxidizer is air) are presented. It is shown that the combustion proceeds in two steps, which differ in temperature. The addition of boron influences the concentrations of A1N, residual A1, and α-Al2O3 in the end products of combustion of mixtures of ultrafine powders of A1 and B in air. For a fixed sample weight of 4 g, the maximum A1N content is observed in the combustion of an A1 + 20% B mixture of ultrafine powders, and the combustion temperature is also maximum in this case. When the sample weight is smaller than a certain critical value, the combustion proceeds in one step. Increasing the sample weight of the starting mixture of ultrafine powders of A1 and B leads to an increase in the A1N content in the combustion products with simultaneous rise in the combustion temperature. A considerable part of the combustion products stabilizes as acicular polycrystals of micron and submicron sizes formed with participation of a gas phase during combustion.
ASJC Scopus subject areas
- Chemical Engineering(all)
- Fuel Technology
- Energy Engineering and Power Technology
- Physics and Astronomy(all)