Плазмово-електролітичний синтез гетерооксидних покривів на високолегованих сплавах алюмінію

Abstract

The scientific principles of control of the composition of heteroxide coatings on aluminum alloys with transition metals are substantiated by varying the formulation of electrolytes, modes and parametersof synthesis by the method of plasma-electrolytic oxidation (PEO). The results of the research aimed to establish a patterns of electrochemical synthesis coatings both mono- and doped oxides in the modes of PEO. The influence of external conditions and internal factors on the structure, element composition, morphology and operating properties of the obtained materials is analyzed. It was established that the composition, surfacemorphology and functional properties of oxide coatings on aluminum alloys depend on the composition of electrolytes andoxidation mode. It is proved the possibility obtaining multicomponent oxide coatings with high adhesionin one-stageusing PEO. It was established that the inclusion of cobalt on the oxide coatings on the aluminumalloy АК12М2МgN leads to formation of a mosaic three–dimensional surface structure, in which the PEO coating contain maximum of cobalt. It is found that mixed oxides coatings systems Al/Al₂O₃, CoOᵧ and Al/Al₂O₃, MnOᵧ, CoOᵧ as promising materials for heterogeneous catalysis can be prepared by electrochemical technology on metal substrates in PEO mode. According to the spectroscopy of the electrode impedance, equivalent schemes of substitution of hetero-oxide systems in different acidity medium have been established. Parameters of multicomponent oxide coatings have been determined, based on which the deep and current corrosion rates have been calculated. It was noted increase of their corrosion resistance in comparison with Al/Al₂O₃ caused by homogenization of the surface layer and the formation of smooth micro globular structure. The system Al/Al₂O₃, MnOᵧ, CoOᵧ identified the highest catalytic properties with the total content of the dopants to 6 at.% in a bench test of the diesel engine in the forced modes reduces fuel consumption.