Effect of the Hydrothermal Treatment on the Microstructural Characteristics and Bioactivity of the Ag Incorporated MAO Coatings Fabricated on Ti6Al7Nb Alloy


Aydogan D. T. , Muhaffel F., Çimenoğlu H.

Surface Innovations, vol.10, pp.252-262, 2022 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 10
  • Publication Date: 2022
  • Doi Number: 10.1680/jsuin.21.00036
  • Journal Name: Surface Innovations
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Compendex, INSPEC
  • Page Numbers: pp.252-262
  • Keywords: Ag release, coatings, crystallization, hydrothermal treatment, micro-arc oxidation, MICRO-ARC OXIDATION, CALCIUM-PHOSPHATE, SUBSTITUTED HYDROXYAPATITE, TITANIUM, COATINGS, ANATASE, SURFACE, TI, ELECTROLYTE, FABRICATION
  • Istanbul Technical University Affiliated: Yes

Abstract

© 2021 ICE Publishing: All rights reserved.In this study, Ti6Al7Nb titanium alloy has been subjected to micro-arc oxidation (MAO) process and hydrothermal (HT) treatment sequentially. MAO process was conducted in a calcium acetate hydrate (Ca(CH3COO)2.H2O) and disodium hydrogen phosphate anhydrous (Na2HPO4) containing reference electrolyte with and without the addition of silver acetate (AgC2H3O2) to provide antibacterial efficiency along with good bioactivity. Subsequently, HT treatment was employed to MAO'ed samples in an alkaline solution (pH = 11) at 230°C. HT treatment induced the covering of the titanium oxide (TiO2) based MAO coatings with 1-2μm thick exterior layer composed of nano-rods of TiO2 and hexagonal columns of hydroxyapatite (HA). The presence of Ag in the MAO coating refined the structure of the HT treatment-induced exterior layer. As the primary indication of enhancement of the bioactivity, HT treatment accelerated apatite formation in the SBF solution irrespective of the Ag presence, which delayed the apatite formation on the untreated MAO coatings. Moreover, HT treatment reduced the release of Ag from the coatings into the SBF solution.