Study of the free falling particles trajectory at the burning monolithic titanium particles

Abstract

The technique for producing the large titanium monolithic burning particles with a diameter of 250-550 microns is developed. The combustion of titanium particles in free fall in air was investigated. The characteristic times for the following events-beginning of fragmentation, end of fragmentation, end of burning, as well as the particle's motion law (including the coordinate and the velocity at the moment when the fragmentation process starts) are defined using the video recording. The size of particle at which the fragmentation picture changes from "star" to "spruce branch" is estimated. The combustion condensed products of particle are sampled and investigated. Three types of products are found. Firestone are objects with aerogel structure with overall dimensions up to thousand microns consisting of the oxide spherules chains with an arithmetic mean diameter of spherules of 85 nanometers. Second are spherical oxide particles with diameter of units-tens of microns. Third are the spherical residues of mother particles with sizes up to hundreds microns (in the case of fragmentation in spruce branch mode).