Comparative corrosion performance of YSZ-coated Ti-13Zr-13Nb alloy and commercially pure titanium in orthopedic implants

Abstract

This study delves into the corrosion performance and wear behavior of orthopedic implant alloys, particularly the Ti-13Zr-13Nb alloy and commercially pure titanium (cp-Ti), both coated with Yttria-Stabilized Zirconia (YSZ) nanoceramic. The research utilizes the Taguchi design of experiments (DOE) approach and employs electrophoretic deposition (EPD) techniques to create thin, well-adhering YSZ layers on these alloys. Employing an orthogonal Taguchi L9 array, the study investigates how various EPD parameters, including electrical voltages, YSZ concentration, deposition duration, and grinding intensity, influence the deposition yield on both Ti alloys. To optimize the EPD parameters for these Ti alloys, the coated substrates underwent thickness and adhesion tests. The optimal conditions established are as follows: for commercially pure Ti, YSZ coating thickness and adhesion were achieved using 60 Vs, 7 min of deposition, 15 % concentration, and 400° of grinding. Meanwhile, for Ti-13Zr-13Nb, the ideal parameters were 60 Vs, 7 min of deposition, 20 % concentration, and 400° of grinding. Comprehensive characterization techniques were employed, including high-resolution scanning electron microscopy (FE-SEM) for alloy analysis, optical microscopy and atomic force microscopy (AFM) for surface microstructure and thickness evaluation, energy-dispersive X-ray spectroscopy (EDAX) for composition analysis, and X-ray diffraction (XRD) for phase analysis.The research goes on to assess corrosion resistance by subjecting the optimal coated Ti alloys to simulated body fluid (SBF) using electrochemical methods such as polarization (Tafel) and cyclic polarization. Additionally, adhesion force was measured using a tip tester. Notably, both cp-Ti and Ti-13Zr-13Nb coatings showcased enhanced corrosion resistance in Ringer's solution at 37 °C. Importantly, the corrosion rate of the coated Ti-13Zr-13Nb alloy (1.888 × 10–3) was found to be lower than that of the coated cp-Ti alloy (3.013 × 10–3)..