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

The results of a quantitative study of the influence of methods of chemical cleaning, pulse treatment with high-voltage electric discharges in a liquid, and flotation separation of synthetic diamond powder of the AS20 grade with a grain size of 100/80 on its abrasiveness are given. It has been established that the use of pulse treatment with high-voltage electric discharges in a liquid provides selective destruction of low-strength diamond particles, activation of the energy state of the surface, and an increase in abrasiveness. Changes in powder characteristics: homogeneity in strength by 1.3-1.9 times; decrease in the mass fraction of impurities by 2.8-7.8 times; guarantee an increase in abrasiveness up to 30-34% and contribute to the improvement of the physico-mechanical and physico-chemical characteristics of synthetic diamond powder

Studies of the impact of high voltage electric discharge (HVED) treatment on the dispersion and phase composition of 87,5 % Al + 12,5 % Cu powder system were performed. It was shown that HVED treatment in ethanol with specific treatment energy of 5 MJ/kg leads to the decrease of mean diameter of treated powder from 15 to 11 μm, and the increase of specific treatment energy to 20 MJ/kg leads to the decrease of mean diameter of treated powder from 15 to 6 μm. X-ray diffraction analysis shows that CuAl2 and Al4C3 are synthesized in all considered treatment regimes, and the quantity of these phases depend on the specific treatment energy.
The use of “three point – plane” electrode system instead of “point – plane” during HVED treatment of 87,5 % Al + 12,5 % Cu powder system in ethanol leads to the increase of quantity of synthesized Al4C3 and CuAl2 phases with the slight decrease in the dispersion efficiency.
Up to 35% of particles in powder mixture, treated by HVED in ethanol with the use of “three point – plane” electrode system, have diameter close to the diameter of the initial powder mixture.
It is shown that the preparation of powders with an initial composition of 87.5% Al + 12.5% Cu using HVED treatment in kerosene or ethanol with subsequent consolidation by SPS method allows obtaining metal-matrix composites of the Al – Cu – C system with increased indicators of hardness, electrical conductivity and wear resistance.