Tribological behavior of PEO layers synthesized on light alloy

The tribological behavior of plasma electrolytic oxidation (PEO) layers synthesized on AMg–6 and D16T alloys (as the analogists of the A95556 UNWS USA and AA2024 ANSI USA) and on PEO layers formed on arc sprayed coatings (ASC) from both solid and cored wires (CW) in electrolyte – 3 g /l KOH + 2 g / l Na2SiO3) by pulse current had been investigated. It has been established that the wear resistanse of the upper and lower PEO layers, synthesized both on the D16T alloy and on the ASC from the solid wire D16 is high. The highest wear resistance during friction with the fixed abrasive have PEO layers synthesized on the D16T alloy and on the ASC from D16 solid wire.The efficiency of the combination of arc spraying (AS) and PEO technologies for the reduction and hardening of surfaces of contact pairs (couples) from light alloys, operating both under conditions of abrasive wear and boundary lubrication is shownVytauto Didžiojo universitetasŽemės ūkio akademij

Tribological behavior of plasma electrolytic oxidation layers synthesized on AMg6 and D16 alloys in couples with cast iron SCh 21–40

The tribological behavior of plasma electrolytic oxidation (PEO) layers synthesized on AMg–6 and D16T alloys (as the analogists of the A95556 UNWS USA and AA2024 ANSI USA) and on PEO layers formed on arc sprayed coatings (ASC) from both solid and cored wires (CW) in electrolyte – 3 g /l KOH + 2 g / l Na2SiO3) by pulse current had been investigated. It has been established that the wear resistanse of the upper and lower PEO layers, synthesized both on the D16T alloy and on the ASC from the solid wire D16 is high. The highest wear resistance during friction with the fixed abrasive have PEO layers synthesized on the D16T alloy and on the ASC from D16 solid wire.The efficiency of the combination of arc spraying (AS) and PEO technologies for the reduction and hardening of surfaces of contact pairs (couples) from light alloys, operating both under conditions of abrasive wear and boundary lubrication is shownVytauto Didžiojo universitetasŽemės ūkio akademij

The effect of electrolyte composition on the plasma electrolyte oxidation and phase composition of oxide ceramic coatings formed on 2024 aluminium alloy

Purpose: Purpose of this work is to analyse the process of synthesis of oxide ceramic coatings in plasma electrolytes on 2024 aluminium alloy and to form an electrolyte which allows to reduce energy consumption for the coating formation. Design/methodology/approach: The oxide ceramic coatings were synthesized on 2024 aluminium alloy. The coatings were formed by the alternate application of anode and cathode pulses to the sample. X-ray diffraction analysis of coatings was performed on a DRON-3.0 X-ray diffractometer using CuKa radiation. The thickness of the coatings was determined using a CHY TG-05 thickness gauge. The porosity of the coatings was investigated by analysing the micrographs of the plasma electrolyte oxidation (PEO) coatings obtained on a scanning electron microscope at x500 magnification using the image processing technique. Findings: The electrolyte with 5 g/l H2O2 additive have been elaborated as an optimal composition for synthesis of a coating with an increased content of corundum (a-Al2O3) as compared to a coating synthesized in the same mode in the 3KOH+2Na2SiO3 electrolyte without H2O2. This synthesis mode allows obtaining a coating with a high corundum content at low energy consumption. Research limitations/implications: For further optimization of the synthesis modes, it is necessary to analyse the influence of the phase composition and porosity of the obtained oxide ceramic coatings on their microhardness, wear resistance, and corrosion resistance. Practical implications: Based on the developed modes of synthesis of the coatings, it will be possible to obtain wear and corrosion resistant oxide ceramic coatings with predetermined functional properties and to reduce energy consumption for their formation. Originality/value: Methods for accelerating the formation of coatings have been proposed and tested, in particular, by adding various amounts of hydrogen peroxide to the electrolyte. The content of oxides in the obtained coatings, in particular, their ratios at various concentrations of hydrogen peroxide in the electrolyte, were determined by X-ray phase analysis. The modes of synthesis of the coatings were developed which allow obtaining a continuous coating without cracks with simultaneous decreasing porosity from 4.32% to 3.55-3.53%