Sol–gel derived nanohydroxyapatite film on friction stir processed Ti–6Al–4V substrate

Abstract

In the present study, friction stir processing (FSP) was successfully carried out on Ti–6Al–4V alloy and nanocalcium phosphate (CaP) particles were incorporated during process. Subsequently, nanohydroxyapatite (HAp) film was effectively synthesised on Ti–CaP nanocomposite interlayer by sol–gel method. The Ti–CaP nanocomposite interlayer and nano-HAp film were characterised by XRD, OM, SEM and EDS. The substrate topography was studied by AFM analysis. The CaP particle size in the nanocomposite interlayer was in the range of 40–100 nm and nano-HAp film obtained was 10–12 μm thickness. It was found that the Ca/P atomic ratio is 1·67 in the nano-HAp film which changes to 1·21 in the Ti–CaP nanocomposite interlayer. Finally, the potentiodynamic polarisation of as received and coated samples in simulated body fluid solution was studied.