Abstract
The paper presents the results of mechanochemical treatment of aluminum powder particles in a ball mill using various organic modifiers (graphite, stearic acid, polyvinyl alcohol) as a surfactant additive in order to increase powder dispersity and modify the surface layer of initial particles. Scanning force microscopy, X-ray diffraction analysis, IR spectroscopy and EDX methods were used to study the morphology, dispersion, structure, and the average particle size of aluminum powders after mechanochemical treatment, and this study showed significant changes in the surface layer of particles. It is found that mechanochemical treatment of aluminum with organic additives leads to partial recovery of the oxide surface layer with several types of active centers formed capable of chemical reactions using the resulting compositions in various combustible mixtures. The study showed that with an increase in the content of modifiers, i.e. graphite and polyvinyl alcohol, the activity of aluminum rises in the composite with these additives. When the content of stearic acid in the Al composite increases, the activity index decreases. This may be due to the fact that Аl–C17H35COOH mixture milling with a large amount of stearic acid (more than 5 %) forms a dense capsule layer on the surface of aluminum particles that is poorly soluble in alkali. During mechanical action the composition powders under study show both the accumulation and redistribution of defects throughout the particle, an increase in the active aluminum content, generation of active centers, and formation of an encapsulating layer based on organic modifiers on the aluminum surface.