Thick PEEK coatings were electrophoretically deposited on Ti–13Nb–13Zr alloy.
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Coatings exhibited very good adhesion to the substrate.
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Coatings significantly improved the alloy tribological properties.
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Coatings increased corrosion resistance of the alloy in the Ringer's solution.
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EPD is very useful to deposit PEEK coatings on Ti–13Nb–13Zr titanium alloy.
Abstract
Polyetheretherketone (PEEK) coatings of 70–90 μm thick were electrophoretically deposited from a suspension of PEEK powder in ethanol on near-β Ti–13Nb–13Zr titanium alloy. In order to produce good quality coatings, the composition of the suspension (pH) and optimized deposition parameters (applied voltage and time) were experimentally selected. The as-deposited coatings exhibited the uniform distribution of PEEK powders on the substrate. The subsequent annealing at a temperature above the PEEK melting point enabled homogeneous, semi-crystalline coatings with spherulitic morphology to be produced. A micro-scratch test showed that the coatings exhibited very good adhesion to the titanium alloy substrate. Coating delamination was not observed even up to a maximal load of 30 N. The PEEK coatings significantly improved the tribological properties of the Ti–13Nb–13Zr alloy. The coefficient of friction was reduced from 0.55 for an uncoated alloy to 0.40 and 0.12 for a coated alloy in a dry sliding and sliding in Ringer's solution, respectively. The PEEK coatings exhibited excellent wear resistance in both contact conditions. Their wear rate was more than 200 times smaller compared with the wear rate of the uncoated Ti–13Nb–13Zr alloy. The obtained results indicate that electrophoretically deposited PEEK coatings on the near-β titanium alloy exhibit very useful properties for their prospective tribological applications in medicine.
