Coatings, with a thickness of up to 75 µm, were formed by plasma electrolytic oxidation (PEO) under the alternating current electrical mode in a silicate-alkaline electrolyte on aluminum composites without additives and alloyed with copper (1–4.5%). The coatings’ structure was analyzed by scanning electron microscopy, X-ray microanalysis, X-ray photoelectron spectroscopy, nuclear backscattering spectrometry, and XRD analysis. The coatings formed for 60 min were characterized by excessive aluminum content and the presence of low-temperature modifications of alumina γ-Al₂O₃ and η-Al₂O₃. The coatings formed for 180 min additionally contained high-temperature corundum α-Al₂O₃, and aluminum inclusions were absent. The electrochemical behavior of coated composites and uncoated ones in 3% NaCl was studied. Alloyage of aluminum composites with copper increased the corrosion current density. Plasma electrolytic oxidation reduced it several times.

Some results of the development of a composite material based on sintered aluminum powder containing small additives of Al₂O₃ nanoparticles produced by the plasma-chemical method are described. The reasons for using small nanoparticle concentrations from the point of view of the role of interphase layer, Orowan hardening mechanism, etc., are given. Some properties and microstructure of produced alumocomposites with various contents of nanoparticles are demonstrated. According to the known laws, the Orowan stress is calculated for investigated composites as one of the possible contributions to an increase in material strength.

New data were obtained on the effect of small additions of nanoparticles on the mechanical properties of a metal matrix produced by cold pressing of powders with subsequent sintering in a forevacuum....

Ceramic-like coatings with a thickness of up to 40 μm are formed on aluminum composites without additives and with copper additives (1 and 4.5%) in a silicate-alkaline electrolyte by microarc...