Microplasma electrochemical deposition of aluminum oxide-polyethylene composite coatings on iron surface

Combination of plasma-electrolytic oxidation and extraction-pyrolytic method for formation of metal oxide layers

“…The samples were electrochemically treated by PEO with an electrolyte containing 0.1 M NaAlO 2 and 0.05 M NaOH [27,28]. The electrolyte was prepared from commercial reagents NaAlO 2 and NaOH of chemically-pure grade.…”

“…In the second group, high currents are passed, which leads to strong gas evolution in the near-electrode region, heating of the metal, boiling of the electrolyte on its surface, formation of a gas-vapor interlayer enveloping the electrode, and its electric breakdowns [14-16, 18, 22, 24, 26]. In this case, the valve metal being processed may also be cathodically polarized [25] in the so-called oxide-forming electrolytes, e.g., in anodic polarization with sodium aluminate NaAlO 2 [18, [26][27][28], or cathodic polarization in nonaqueous electrolytes with Al(NO 3 ) 3 [25]. In both cases, coatings containing aluminum oxides Al 2 O 3 are formed on the surface of nonvalve metals.…”

“…have been under development. No passive oxide layers with a valve (diode) effect are formed in anodic polarization on the surface of metals of this kind [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28].The already developed, or being discussed in the literature, approaches to coating formation by PEO on metals and alloys of the nonvalve group can be conditionally divided into three groups. In the fi rst of these, a layer of a valve metal, commonly aluminum or its alloys, with a certain thickness is preliminarily deposited on the surface and then processes into an oxide RUSSIAN JOURNAL OF APPLIED CHEMISTRY Vol.…”

“…The bismuth concentration in the aqueous phase was 3 × 10 -2 M. The saturated bismuth extracts were deposited onto substrates, with wetting several times alternated with drying at a temperature of 50-70°C. After the solvent was removed, the precursors obtained were subjected to pyrolysis at a temperature of 860-900°C.The samples were electrochemically treated by PEO with an electrolyte containing 0.1 M NaAlO 2 and 0.05 M NaOH [27,28]. The electrolyte was prepared from commercial reagents NaAlO 2 and NaOH of chemically-pure grade.…”

“…have been under development. No passive oxide layers with a valve (diode) effect are formed in anodic polarization on the surface of metals of this kind [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28].…”