International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

In this study, we present the key results of computer modeling and experimental series of a combined technological process that integrates hydro-vacuum atomization and hydrogenation of metallic melts. The simulations considered several representative cases in which lead, aluminum, magnesium, Armco iron, and magnesium–aluminum alloys were used as initial materials. A comparative analysis of the obtained data revealed that, during hydro-vacuum atomization, the cooling, solidification, and hydrogenation kinetics of atomized droplets are strongly governed by the specific thermodynamic characteristics of the metals, such as the solidification interval, latent heat of fusion/solidification, and specific heat capacity. It was established that the relationship between the melt overheating temperature and the width of its solidification interval constitutes a key controlling factor in the combined processes of atomization and hydrogenation. This factor is critical because it determines both the duration and the nature of the residence of atomized metallic droplets in the transitional liquid–crystalline state, thereby defining the temporal window and the depth of highly effective physico-technological influences that promote hydrogen uptake. These influences arise during the entrainment and breakup of the melt jet in the water stream and include hydromechanical activation, structural metastabilization, and interstitial hydrogen incorporation released from collapsing cavitation cavities in water due to the thermobaric energy generated during their directed cumulative implosion.

The study is devoted to the identification of technological features of the process of hydrovacuum dispersion (atomization) of liquid aluminium, which provides the accompanying self-generation of the effect of sonochemical hydrogenation of the obtained particles. In order to explain this phenomenon, the study reveals the design and functional features of a special, actually developed installation of continuous vertical suction and dispersion of metallurgical melts. Here the graphical scheme-model of influence of ultrafrequency cavitation pulsation generated by shock waves of hydraulic rarefaction, cumulative splitting of water molecules and sonochemical introduction of released hydrogen in solidifying particles of atomized aluminum melt is reconstructed. The results of the revealed sonochemical hydrogenation process are clearly illustrated by both electron microscopy images and X-ray diffractometry and FTIR spectroscopy. It is established that during hydrovacuum atomisation free hydrogen can be dissolved and retained in aluminum microparticles, both with the formation of blown (foamed) clusters of diffusion-amorphous hydrogenation, and – solid solution of embedding, in the form of crystals of face-centred cubic syngony.

A novel technology for producing metal powders is presented, the distinctive feature of which are the conditions of forming of powder particles. In particular, under the proposed technology the melt is sucked bottom-up by the vacuum produced by the toroidal vortex of the discharged nucleus of high-pressure water flow in the two-layer cylindrical shell cavity, where it is being dispersed as metallic particles and carried over from the working medium to a special store. The so produced powders have a particular morphology and structure, increased specific surface area and microhardness.