Formation of Protective Composite Coatings on Mg Alloy by Plasma Electrolytic Oxidation Method with Using Organofluorine Materials

摘要

The results of surface modification of magnesium alloys by plasma electrolytic oxidation (PEO) and subsequent treatment in suspension of superdispersed polytetrafluoroethylene (SPTFE) and telomeric solution of tetrafluoroethylene (TFE) have been presented. Composite coatings were obtained by dipping with subsequent heat treatment. Electrochemical, tribological properties and wetting ability of obtained protective composite coatings were investigated. The best protective properties were obtained for coatingswith fourfold application in SPTFE suspension. The obtained coatings decrease the corrosion current (5.4 10~(-11) A cm~(-2)) and wear (7.6 10~(-7) mm~3 (N m)~(-1) ), increase polarization resistance (4.9 10~8 Ω cm~2) and impedance modulus (1.9 10~9 Ω cm~2) by orders of magnitude compared to unprotected magnesium alloy and base PEO-coating. The highest value of contact angle (CA) was obtained for coatings with triple application in telomeric solution. CA for such composite coatings attaint to 168±2°.