Chemical gradient in plasma-sprayed hydroxyapatite coatings on Ti substrate

Reliability of HA coatings depends, on microstructure and chemistry of the coatings, which are affected by coating processing. Considering difference in cooling rates of molten HA particles impacting on Ti substrate, certain chemical or physical changes from near Ti interface to the coating surface might exist. The HA grain size difference with distance from the interface was observed by transmission electron microscopy. This study focused on inhomogeneous features of HA coatings in order to have a better understanding and better control of plasma sprayed HA coatings. (Substrate: titanium alloy Ti-6Al-4V.)