Electrodeposition of hydroxyapatite coating on AZ91D magnesium alloy for biomaterial application

Magnesium and its alloys are potential biodegradable implant materials due to their attractive biological property. But their poor corrosion resistance may result in the sudden failure of the implants. The bioactive hydroxyapatite (HA) coating was electrodeposited on AZ91D magnesium alloy surface to improve its biodegradation performance. The biodegradable behavior of HA coating was investigated by electrochemical tests and immersion tests. The experimental results indicated that the as-deposited coating consisting of dicalcium phosphate dehydrate ((DCPD, CaHPO4 center dot 2H(2)O) and beta-tricalcium phosphate (beta-TCP, Ca-3 (PO4)(2)) was transformed into uniforryl hydroxyapatite (HA, Calo (PO4)(6)(OH)(2)) coating after immersion in 1 M NaOH solution for 2 h. The HA coating can obviously slow down the biodegradation rate of AZ91 D magnesium alloy in stimulated body fluid (SBF). (c) 2008 Elsevier B.V. All rights reserved.