The authors have presented results of investigation into the process of combustion of solid specimens consisting of ammonium perchlorate and a binder with boron and aluminum-dodecaboride additives by the method of small-angle x-ray scattering with a high time resolution using high-speed optical photography. An analysis has been made of the particles preserved after the combustion. It has been shown that the procedure of small-angle x-ray scattering permits recording particles of the B and AlB12 additive directly in the combustion wave of the compound.