Surface characteristics and in-vitro behavior of chemically treated bulk Ti6Al7Nb alloys

ESEN Z., Ocal E. B.

SURFACE & COATINGS TECHNOLOGY, cilt.309, ss.829-839, 2017 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 309
  • Basım Tarihi: 2017
  • Doi Numarası: 10.1016/j.surfcoat.2016.10.078
  • Dergi Adı: SURFACE & COATINGS TECHNOLOGY
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.829-839
  • Anahtar Kelimeler: Ti6Al7Nb alloy, Sodium, Calcium, Simulated body fluid, Apatite, X-ray photoelectron spectroscopy, RAY PHOTOELECTRON-SPECTROSCOPY, BIOACTIVE TITANIUM METAL, SIMULATED BODY-FLUID, APATITE-FORMATION, PHYSIOLOGICAL SOLUTION, TI METAL, OXIDATION TREATMENT, AQUEOUS NAOH, PASSIVE FILM, THIN-FILMS
  • Orta Doğu Teknik Üniversitesi Adresli: Hayır

Özet

The effect of various treatments on surface chemical composition and structure, and bioactivity of Ti6Al7Nb bulk alloys has been investigated. The alloys were treated employing aqueous solutions of NaOH and CaCl2 separately, and also by subsequent CaCl2 treatment after NaOH treatment (NaOH-CaCl2 treatment) which were followed by heat treatment. NaOH treatment was observed to be effective in enrichment of surface layer with Na. On the other hand, Na+ ions were mostly replaced by Ca2+ ions as a result of NaOH-CaCl2 treatment, while single step CaCl2 treatment was less effective in Ca incorporation. Additionally, porous network surface structure seen in NaOH and NaOH-CaCl2 treated samples was completely different than globular morphology detected in CaCl2-treated samples in single step. Subsequent heat treatments caused coarsening of surface structure and loss of some Na+ and Ca2+ ions. NaOH and NaOH-heat treated samples did not exhibit apatite formation within 15 days immersion in simulated body fluid (SBF). On the other hand, NaOH-CaCl2 samples had the highest apatite formation; however, NaOH-CaCl2-heat treated samples did not display any mineralization. Conversely, CaCl2 treated samples allowed apatite formation after heat treatment. (C) 2016 Elsevier B.V. All rights reserved.