Surface Properties of Graphene Functionalized TiO2/nHA Hybrid Coatings Made on Ti6Al7Nb Alloys via Plasma Electrolytic Oxidation (PEO)

YİĞİT O., ÖZDEMİR N., DİKİCİ B., Kaseem M.

MOLECULES, cilt.26, sa.13, 2021 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 26 Sayı: 13
  • Basım Tarihi: 2021
  • Doi Numarası: 10.3390/molecules26133903
  • Dergi Adı: MOLECULES
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Biotechnology Research Abstracts, CAB Abstracts, Chemical Abstracts Core, Communication Abstracts, EMBASE, Food Science & Technology Abstracts, MEDLINE, Metadex, Veterinary Science Database, Directory of Open Access Journals, Civil Engineering Abstracts
  • Anahtar Kelimeler: graphene, PEO, Ti6Al7Nb, hydroxyapatite, in-vitro corrosion, HYDROXYAPATITE COMPOSITE COATINGS, MICRO-ARC OXIDATION, CORROSION-RESISTANCE, BIOCERAMIC COATINGS, TITANIUM-ALLOYS, POTENTIODYNAMIC POLARIZATION, PHYSICOCHEMICAL PROPERTIES, BIOMEDICAL APPLICATIONS, MECHANICAL-PROPERTIES, PHOSPHATE COATINGS
  • Atatürk Üniversitesi Adresli: Evet

Özet

Nano-hydroxyapatite (nHA)-matrix coatings containing graphene nanosheets (GNS)-nHA were coated on Ti6Al7Nb alloys by plasma electrolytic oxidation (PEO) treatment for the improvement of their surface properties. Crystallographic properties, functional groups, and elemental analysis of coatings were characterized by XRD, ATR-FTIR, and EDS analysis. Surface morphological changes of the coated surfaces were investigated by AFM and SEM. The electrochemical corrosion behavior of the coatings was examined by using the potentiodynamic scanning (PDS) tests under in-vitro conditions in simulated body fluid (SBF). The results showed that the GNS was successfully deposited in ceramic matrix coatings on Ti6Al7Nb alloys. Also, the microstructural observations revealed that the coatings have a porous and rough structure. The XRD and ATR-FTIR quantitative analysis have proved the appearance of HA and GNS in the coating layers. An increase in the coating thickness, surface hardness, and anatase/rutile transformation rate was determined, while the GNS ratio in the coating layers was increased. The microhardness of the nHA coating reinforced with 1.5 wt% GNS was measured at 862 HV, which was significantly higher than that of GNS-free (only nHA) coating (584 HV). The best in-vitro resistance to corrosion in SBF was observed in the nHA/1.5GNS wt% coating.