Functionally graded Ti/HAP coatings on Ti–6Al–4V obtained by chemical solution deposition

Graded Ti100−x/HAPx (x=0 – 100%) films were prepared on Ti–6Al–4V implants by chemical solution deposition using a titanium-isopropoxide chelated by acetylacetone, calcium nitrate and phosphoric acid as starting materials. Ti/HAP solutions with variable HAP contents from 0 to 100% at 10% intervals were spin coated on the substrates and prefired at 500 °C. X-ray diffraction and field emission-scanning electron microscope analysis showed that Ti/HAP coatings were obtained with a dense interface between coating and substrate by final annealing at 500 °C and higher. The effectiveness of the functionally graded HAP/Ti coatings was discussed based on the analysis of the variation of Ca and P contents in simulated body fluid as a function of annealing temperature.