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Ключевые слова: плазмоэлектролитическая обработка, щелочной
электролит, механизм плазмоэлектролитического оксидирования, металооксидные
композиционные слои, износостойкость, газотермические покрытия, ПЭО слой.

ANNOTATION
Sirak Y.Y. The effect of copper and nickel on the formation of plasma
electrolytic layers in the aluminum thermal spray coatings. – Manuscript.
Dissertation for the Candidate’s degree of speciality 05.02.01 — Materials science.
— Karpenko Physico-Mechanical Institute of the NAS of Ukraine, Lviv, 2018.

The work is devoted to the study of the influence of alloying elements (of the
copper or nickel) inside thermal spray coatings on the mechanism of the plasma-
electrolytic oxidation and on the physical and mechanical characteristics of the PEO
layers. It was first established that during the synthesis of aluminum thermal spray
coatings alloyed by such metals, whose oxides are restored by an aluminum melt in
the plasma channels, the metal oxide composite layers based on the corundum with
the ductile metal inclusions (of the copper or nickel) are synthesized instead the
simple oxide layers. Such composite layers have enhanced of the tribological
characteristics and wear resistance at the cyclic and impact loading. The optimum
content of the copper or nickel in the layer was 5...10 wt. %.
Based on thermodynamic calculations and their experimental approbation, the
models for the synthesis of copper- and nickel-containing oxide layers on the alloyed
of thermal sprayed coatings during their plasma-electrolytic treatment (micro arc
oxidation) in alkaline electrolytes have been developed. It was established the
sequence of the reactions occurring in the plasma channels and the relationship
between the energy of a single plasma discharge during the synthesis of the PEO
layer and the size of the metallic inclusions in it.
It was first revealed the selective mass transfer effect at the conditions of the
boundary lubrication during frictional interaction of a friction pair - a PEO layer with
the inclusion of dispersed copper inclusions (as a disk) - a cast iron (as a liner) - in an
oil with addition of 1% aqueous glycerin solution (2.5% vol.). As a result of this
effect the coefficient of friction and the amount of wear of a liner was reduced by an
order of magnitude. Research-industrial attestation of the printing equipment drums
for the enterprise Biblos LLC shown the effectiveness of their restoration after
operational wear using of the combined technology: with application of aluminum
thermal spray coatings with subsequent of their finishing treatment using PEO
technology. The durability of drums with a protective coating on the proposed
technology has increased by 2-2.5 times compared to the galvanic chromium plating.
Key words: plasma-electrolytic treatment, alkaline electrolyte, mechanism of
micro arc oxidation, metal oxide composite layers, wear resistance, thermal sprayed
coatings, PEO layer.