Slurry Erosion and Corrosion Behavior of Some Engineering Polymers Applied by Low-Pressure Flame Spray

Abstract

The erosive wear and corrosion resistance of three types of flame spray-deposited polymer coatings was analyzed. The erosive wear test was performed in slurry pot tester with rotational movement using distilled water and mix quartz particles (300 g/l). Two impact angles of the particles were used, reaching 4.15 m/s average impact velocity. Corrosion resistance of the polymer coatings and degradation behavior were investigated by electrochemical impedance spectroscopy in a solution of 0.5 M sodium chloride at room temperature for a total immersion time of 1 year. The interpretation of the results was made according to the Bode plot. It is proven a better slurry erosion wear performance for PEEK and PA12 coatings when the particles impact at 90° angle. For impact angle of 30°, there is no significant difference in the erosion performance of PEEK, PEI, and PA12 coatings. No major changes occurred in the impedance module for PA12 and PEEK samples, indicating that these coatings can protect the steel substrate for extended periods of time. The lower PEI performance is believed to be related to the improper choice of spraying parameters, as the spray conditions were kept constant for the three feedstock materials.