Effect of strontium-doped coating prepared by microarc oxidation and hydrothermal treatment on apatite induction ability of Ti13Nb13Zr alloy in vitro

Composite coatings with the variable contents of Sr substituted for Ca in hydroxyapatite (HA) were prepared on the surface of Ti13Nb13Zr alloy by the combination of microarc oxidation (MAO) and hydrothermal treatment (HT). The experimental results show the obvious rod-like HA/Sr-HA crystals in the MAO-HT coatings with various Sr contents. A good hydrophilicity is presented in all surfaces after the MAO-HT treatment and especially in the 40-Sr sample with superhydrophilicity. The coating surfaces with various Sr contents show different degrees of apatite coverage by SBF immersion experiment and also showing the best in the 40-Sr sample. The apatite induction ability of the coatings can be effectively improved by adding Sr. However, the effect of Sr contents on apatite induction is limited. The apatite induction ability is decreased and even inhibited when the Sr doping exceeds 70%.

Automated summary

Composite coatings with variable Sr contents were prepared on the surface of Ti13Nb13Zr alloy using microarc oxidation and hydrothermal treatment. The coatings exhibited rod-like HA/Sr-HA crystals and showed good hydrophilicity. The coatings with different Sr contents had varying degrees of apatite coverage, with the 40-Sr sample having the best coverage. Sr addition improved the apatite induction ability of the coatings, but the effect was limited and decreased when Sr doping exceeded 70%.