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Preparation and characteristics of nano‐grained calcium phosphate coatings on titanium from ultrasonated bath at acidic pH
Author(s) -
Narayanan R.,
Kwon TaeYub,
Kim KyoHan
Publication year - 2008
Publication title -
journal of biomedical materials research part b: applied biomaterials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.665
H-Index - 108
eISSN - 1552-4981
pISSN - 1552-4973
DOI - 10.1002/jbm.b.30941
Subject(s) - materials science , acicular , scanning electron microscope , titanium , chemical engineering , electrolyte , current density , phosphate , phase (matter) , coating , metallurgy , mineralogy , composite material , microstructure , chemistry , physics , organic chemistry , electrode , quantum mechanics , engineering
Abstract Electrochemically deposited nano‐grained calcium phosphate coatings were produced on titanium substrates using aqueous electrolyte at acidic pH. Different coatings were produced by using cathodic current densities ranging from 10 to 50 mA/cm 2 from an ultrasonated electrolytic bath. These coatings contained dicalcium phosphate dihydrate as the predominant phase and hydroxyapatite as the minor phase. With increasing current density, hydroxyapatite content in the coatings increased. Dicalcium phosphate grains had size in the range of 55–85 nm and hydroxyapatite had grains in the size range of 20–25 nm. Scanning electron microscopy showed that the morphology of the coatings obtained at lower current densities had acicular structure. With increasing current densities, the needles became blunt and small and finally, at 50 mA/cm 2 the coating had globular deposits. Surface roughness of the coatings also increased with increasing deposition current density. Tensile bond strengths of the coatings were in the range of 3.6–6.9 MPa and decreased with increase of deposition current density. Heat‐treatment of the coatings for 2 h at 500°C completely eliminated the dicalcium phosphate phase and resulted in mono hydroxyapatite phase containing grains in the size range of 20–30 nm. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008