Effects of applied voltage on the microstructure and properties of hydroxyapatite bioceramic coatings formed on Ti7Cu5Sn titanium alloy by micro-arc oxidation |
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| Authors: | L. C. Tsao |
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| Affiliation: | 1. Department of Materials Engineering, National Pingtung University of Science &2. Technology, Neipu, Taiwan |
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| Abstract: | The effects of the applied voltage on the morphology, composition and corrosion behaviour of Ti7Cu5Sn coated were investigated. At applied voltages lower than 250?V, the composite coatings consist of anatase-TiO2, rutile-TiO2, DCPD(CaHPO4·2H2O) and a small amount of amorphous calcium phosphate phase. When the applied voltage is increased, the ceramic coatings transform from DCPD (CaHPO4·2H2O) to HA (Ca10(PO4)6(OH)2, 300?V), and new phases of Ca2P2O7, CaTiO3 and TCP(Ca3(PO4)2) form at 350?V. The passive current densities at body potential are one order of magnitude lower than that of the uncoated sample, indicating better corrosion resistance. The MAO film is a tri-layer system: a compact inner layer, a mesosphere porous oxide layer, and an outer layer. |
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| Keywords: | Ti7Cu5Sn micro-arc oxidation hydroxyapatite corrosion behaviour |
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