Production and characterisation of hydroxyapatite to be used as coating on prostheses via powder metallurgy

Hydroxyapatite can be used as a coating for metallic prostheses. At present plasma spray is the technique used for coating metallic prostheses. The main disadvantages associated with this technique include unpredictable phase formation during deposition, due to the high temperature involved in the process, and a lack of adherence to the substrate. Alternative techniques to plasma spraying (PS), e.g. powder metallurgy (PM), have been studied. PM technique can produce a coating where the size of the porosity can be controlled. In this work analyses have been performed on composition (MEV-EDS /X-ray Diffraction), morphology (MEV), particle size (Optical Microscopy - Image Analysis), porosity (Mercury Intrusion Porosimetry) and surface area (Gas Adsorption - BET) of the starting powder (HA). The aim of this work is to have full control of all parameters which can influence the sintering of the HA.