Electrophoretic deposition of PEEK-nano alumina composite coatings on stainless steel

Polyetheretherketone (PEEK)-Al2O3 composite coatings have been successfully deposited on 316L stainless steel substrates by electrophoretic deposition (EPD) from ethanolic suspensions containing nanosize alumina and micrometric PEEK particles. Uniform composite coatings containing between 20 and 70 wt.% of PEEK have been obtained. An electrostatic interaction between the two kinds of particles has been confirmed by zeta potential and TEM analysis. The EPD yield increased with deposition time and difference of potential applied following a logarithmic trend. Reproducible PEEK-alumina coatings were deposited. A heat treatment at 343 °C for 30 min with a heating rate 10 °C min− 1 was needed to increase the adhesion substrate-coating. EPD can be considered a convenient low cost method to produce PEEK-Al2O3 composite films on metallic substrates. Scratch test analysis and hardness measurements showed that the deposited coatings were too rich in alumina and that a lower amount of alumina would be enough to satisfactorily increase the mechanical properties. The corrosion resistance of the coatings in chlorine environment was tested. It was shown that PEEK-alumina composite coatings performed better than pure PEEK films and exhibited a significant increase in the pitting potential compared to uncoated stainless steel substrate.