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Indexed by:期刊论文

Date of Publication:2010-07-01

Journal:ACTA BIOMATERIALIA

Included Journals:SCIE、PubMed、Scopus

Volume:6

Issue:7

Page Number:2816-2825

ISSN No.:1742-7061

Key Words:Micro-arc oxidation; Equal channel angular pressing; Coating; Ultrafine-grained titanium; Nanocrystalline hydroxyapatite

Abstract:Equal channel angular pressing results in ultrafine-grained (similar to 200-500 nm) Ti with superior mechanical properties without harmful alloying elements, which benefits medical implants. To further improve the bioactivity of Ti surfaces, Ca/P-containing porous titania coatings were prepared on ultrafine-grained and coarse-grained Ti by micro-arc oxidation (MAO). The phase identification, composition, morphology and microstructure of the coatings and the thermal stability of ultrafine-grained Ti during MAO were investigated subsequently. The amounts of Ca, P and the Ca/P ratio of the coatings formed on ultrafine-grained Ti were greater than those on coarse-grained Ti. Nanocrystalline hydroxyapatite and alpha-Ca(3)(PO(4))(2) phases appeared in the MAO coating formed on ultrafine-grained Ti for 20 min (E20). Incubated in a simulated body fluid, bone-like apatite was completely formed on the surface of E20 after 2 days, thus evidencing preferable bioactivity. Compared with initial ultrafine-grained Ti, the microhardness of the E20 substrate was reduced by 8% to 2.9 GPa, which is considerably more than that of coarse-grained Ti (similar to 1.5 GPa). (C) 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.