Introducing natural hydroxyapatite-diopside (NHA-Di) nano-bioceramic coating

Abstract In the presented study, the deposition of nanostructured NHA-Di (natural hydroxyapatite-diopside) composite coatings on the surface of Ti-6Al-4 V implants is studied. The effect of electrophoretic deposition (EPD) voltage, Di content and process temperature on the surface roughness is also investigated. The powders are characterized by X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray fluorescence (XRF). The atomic force microscopy (AFM) is also used to study the surface topography. According to SEM observations, there are hard agglomerates in the NHA-Di composite powders at low percentage of Di; however they are broken down by increasing the amount of Di percentage. Images which were obtained from the 2D AFM analysis of the NHA-Di coating after its deposition on Ti alloy specimen surface, indicated that the “Roughen” diagram fluctuates between the range of −0.03 and 0.01 μm under the conditions that the Di content reaches 30 wt%. A specific load is applied during the adhesion test which resulted in NHA-30 wt% Di coating maintain its impeccability while the NHA-0 wt% Di coating samples were damaged.A graph is also developed based on the Hertz stress which proved to be challenging in terms of chemical stability based on its surface roughness.