A comparative study of the bio-tribocorrosion behaviour of PEO coated AZ31 magnesium alloy in SBF: Assessing the effect of B, Cu and Zn doping

AZ31 alloy is a widely used material in biomedical applications. It is an alternative alloy for temporary implantation due to its low weight and superior biocompatibility. However, surface properties such as wear and corrosion are quite weak compared to other metallic biomaterials. It is extremely important to improve the surface properties, as these two mechanisms cause very serious material damage on Mg alloys separately or synergistically. In this context, oxidation processes are carried out with the plasma electrolytic oxidation (PEO) method, which provides very successful adhesion in alloys such as AZ31. In this study, the tribocorrosion performance of the films produced by doping Cu, B and Zn elements using PEO was investigated. The simultaneous effects of corrosion and wear mechanisms on surfaces were investigated with experiments carried out in artificial body fluid (SBF). It was concluded that the porous oxide films undergo morphological changes with the effect of additive elements, this change in morphology has a barrier effect, especially against corrosion attacks, and the improved corrosion resistance also improves the wear performance. According to the OCP measurements made under wear, the surface that showed the most noble behavior was Zn-doped (−0.71 V). A similar behavior can be mentioned for the wear test carried out together with the potentiodynamic polarization test. It minimized the Zn current density value in the structure (2.3 × 10−6 A/cm2).