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 Ti6Al4V 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 Ca^(2+) 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 600.10~6 in I cm^3 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.

High Field Environment for EPM at the LNCMI

The Laboratoire National des Champs Magn(?)tiques Intenses(LNCMI) is the CNRS French National High Magnetic Field Facility associated with three universities:Joseph Fourier in Grenoble,Paul Sabatier and INSA in Toulouse.It delivers to researchers direct current high magnetic field up to 35 teslas in 34 mm in Grenoble and pulsed field up to 80 T in Toulouse.Developments of new high field magnets and associated instrumentations are user oriented. These developments(highly homogeneous magnets,magnets for diffraction studies,high field gradient magnet...) are impulsed by different user communities.Since a few years,magneto-science is attracting new users for the study of high field effects on physical,chemical and biological processes such as electrochemistry,metallurgy,nanostructuration, implying new methodologies and new experimental developments such as high temperature environment up to 1600 K.A survey of these developments is given.The laboratory is supported by the European Commission which contributes for the 'Transnational Access' to the facility.