NANO HYDROXYAPATITE COATING ON STAINLESS STEEL 304 BY ELECTROCHEMICAL METHOD

Abstract

Hydroxyapatite and other calcium phosphates are the most important mineral parts of human bone. HA is applied on 304 stainless steel using cathodic electrodeposition in an electrolyte consisting of Ca ( NO 3)2 and NH 4 H 2 PO 4. The effect of electrodeposition parameters such as voltage, temperature and current density on the morphology and adhesion of the deposits were examined. Needle-like structure with nano width was obtained at 80°C and 2V while higher operating voltage resulted in flake type and coarse needle-like deposits. In fact, the lower voltage can change the electronation and diffusion of acting species. The adhesion of the coating, examined by tape test, improved by this method. TEM and SEM images showed the needle-like structure with nanometric width which is very similar to structure of natural bone. Corrosion resistance of the deposits was checked using polarization method and confirmed better performance of the nano HA coating.