Development and characterization of MAO bioactive ceramic coating grown on micro-patterned Ti6Al4V alloy surface

- MAO combined with FPSP process is superior to the simple MAO.
- The rougher dimple surface interspersed by fine pore structure exhibited better bioactivity.
- The fatigue was improved due to the introduced residual compressive stress by FPSP.
- The wear resistance was improved by the alleviated three body wear.

In this paper, we describe a strategy for growing bioactive ceramic coatings on a micro-patterned Ti6Al4V alloy substrate using microarc oxidation (MAO) combined with fine particle shot-peening (FPSP) process, for the purpose to obtain the bio-activated titanium alloy with improved wear resistance and fatigue properties. The microstructure and phase composition of FPSP-MAO coating and simple MAO coating were examined using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The bioactivity, tribology and fatigue properties of FPSP-MAO and simple MAO coated samples were evaluated comparatively. The results indicate that the FPSP-MAO5 coating with a rougher dimple surface interspersed by fine pore structure has better inducing capacity of biomimetic apatite compared with simple MAO5 coating. FPSP-MAO5 and FPSP-MAO10 coated samples exhibit an improved fatigue life, increasing by 12.6% and 8.4% in comparison to that of the simple MAO5 and MAO10 coated ones, which is possibly attributed to residual compressive stress induced in the substrate near the coating/substrate interface. The wear resistance of FPSP-MAO5 and MAO10 coatings was significantly improved caused by the alleviated three body wear due to the debris container effect of dimples structure.