A study on the effect of tantalum penta oxide incorporation in PEEK-based composite coating: a detailed investigation of wear and corrosion resistance

Cost-effective orthopedic implants of 316L SS are good for load bearing applications, but these implants are prone to failure due to poor wear and corrosion resistance compared to titanium implants. Surface modification of 316L SS through composite coating can mitigate these problems. In this study, polyetheretherketone (PEEK) and tantalum pentoxide (Ta₂O₅) composite coating was deposited on 316L SS via electrophoretic deposition (EPD) at optimized parameters (applied electric field 10 V/cm with a deposition time of 7 min). Scanning electron microscope (SEM) images showed uniform morphology with a heterogeneous distribution of Ta₂O₅ particles within the PEEK matrix. Fourier transform infrared (FTIR) spectroscopy identified the characteristic peaks of functional groups of PEEK and Ta₂O₅ and confirmed the successful incorporation of Ta₂O₅ particles in the composite coating. The presence of Ta₂O₅ particles in the composite coating tuned the average surface roughness 1.79 ± 0.17 µm and wettability in terms of contact angle 67 ± 3° in the required range for cellular response. The wear studies conducted using pin on disc method demonstrated that composite coating incorporated Ta₂O₅ particles in PEEK matrix exhibited lower coefficient of friction (COF) and specific wear rate than that of the PEEK coating alone. Electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP) revealed that the Ta₂O₅ particle incorporation improved the corrosion resistance of composite coating compared to that of the 316L SS and PEEK coating. Thus, the developed composite coating demonstrated suitable properties required for orthopedic implants.