hydroxyapatite/silica nanopowders deposition on ti substrate by plasma spray method

In this work, hydroxyapatite/silica nanopowders were granulated to fabricate plasma sprayable feedstocks. for this purpose, the wet powders obtained by heating a hydroxyapatite/silica slurry were stirred and sieved. to realize the feedstock application in the plasma spray process, powders were deposited on titanium substrate. the morphology of granulated feedstock and sprayed coating was studied using field emission scanning electron microscopy (fesem). the evaluation of sprayable powder such as apparent density and flow rate of feedstock was performed according to astm nos. b 21299 and b 21303 standards. the results demonstrated that the granules were spherical and semispherical in shapes. the apparent density and flow rate of granulated feedstock were 540 kg/m3 and 0.1089 gr/sec, respectively. also, the granules yielded the coating with molten/unmolten regions and porosity.