Combustion of aluminum and boron agglomerates free falling in air. II. Experimental results

The combustion of $\mathrm{Al}/\mathrm{B}$ agglomerates $(0.81/0.19)$ with a diameter of $320$–$780$ $\mu$m in free fall in air was first studied by the method of model monodisperse agglomerates method. The dependence of the burning time on size was determined. Burning residue particles were subjected to morphological, chemical, mass, particle size, and elemental (EDS method) analyses. It has been found that the essential features of the combustion mechanism of $\mathrm{Al}/\mathrm{B}$ agglomerates compared to aluminum are long combustion; the specific core-shell structure of the particles, with boron present in the core and absent in the shell; a slight change in mass and diameter of particles during combustion.