Microstructure and performance of microarc oxidation coatings doped with yttrium on TA4 commercial pure titanium

Titanium is a bioinert material and exhibits limited corrosion resistance. Therefore, it is difficult for titanium implants to meet the requirements for long-term stable service in complex in vivo environments. To address these issues, we fabricated yttrium-doped TiO2 coating on TA4 via microarc oxidation technology. We systematically investigated the effects of yttrium acetate [Y(CH3COO)3] incorporation on the microstructure, adhesion strength, phase structure, chemical composition, surface roughness, wettability, corrosion resistance, and biocompatibility of the coatings. Although yttrium doping did not alter the phase composition of the coatings, it significantly affected its microstructure. As Y(CH3COO)3 concentration increased, the porosity, thickness, and surface roughness of the coatings first increased and then decreased. At a Y(CH3COO)3 concentration of 0.4 g/l, the coating exhibited the most compact inner layer, the highest adhesion strength, and significantly enhanced corrosion resistance. In addition, the coating surface demonstrated enhanced hydrophilicity and markedly promoted the adhesion, spreading, and proliferation of MC3T3-E1 osteoblasts. This work offers a reference for optimizing the surface performance of titanium implants.