Morphology Change of Electrodeposited Calcium Phosphate Coating on Ti6Al4V Substrate Under High Magnetic Field

The present study reports on the growth of calcium phosphate coatings on Ti6A14V substrate by electrodeposition under high magnetic field.The electrodeposition is conducted by potentiostatic method on horizontal electrode whose roughness was modified to reach a value of 3μm.The coatings are obtained from an electrolyte containing calcium nitrate as the Ca2+source and ammonium phosphate as the P source with a Ca/P ratio equal to two.The LNCMI high field continuous magnet in a 170 mm bore with homogeneity of 600.10-6in 1 cm3 has been used.The magnetic field with a magnitude up to 12 T is applied perpendicularly to the electrode surface.The surface morphology and chemical composition of the obtained coatings were characterized by 3D digital microscope and scanning electron microscopy associated with X-ray microanalysis（SEM-EDX）.The phase composition was analyzed by X-Ray diffraction.The presence of several crystalline phases comprising octacalcium phosphate and hydroxyapatite is obtained and magnetic field seems to change the relative importance of these phases.The coating morphology changes from belt shape crystallites to needle shape crystallites with high magnetic field superimposition without important modification of Ca/P ratio in the deposit.On the other hand formation of volcano-like structures due to the presence of hydrogen bubbles during deposition is considerably reduced in the presence of magnetic field.