Multifunctional polymer-containing coatings on magnesium alloys

Abstract

The results of surface modification of magnesium alloys by plasma electrolytic oxidation (PEO) and post-treatment in suspension of tetrafluoroethylene (TFE) telomeric solution or superdispersed polytetrafluoroethylene (SPTFE) dispersion have been presented. Electrochemical, tribological properties and wetting ability of obtained protective composite coatings were investigated. The fabricated coatings decrease both the corrosion current density (1.7×10-9–5.4×10-11 A/cm2) and wear (9.8×10-6–7.6×10-7 mm3/(N m)) by orders of magnitude as compared to bare magnesium alloy (5.3×10-5 A/cm2 and 3.8×10-3 mm3/(N m)) and base PEO-coating (2.4×10-7 A/cm2 and 1.7×1-3 mm3/(N m)). Moreover, coatings obtained by means of PEO and polymer dispersion dipping possess hydrophobic and superhydrophobic properties. Such multifunctional coatings have high corrosion resistance and good friction coefficient under dry wear conditions that extends the application field of magnesium alloys.