Structure and Phase Distribution of the Electrophortically Deposited Hydroxyapatite and Cerium Oxide

HydroxyApatite (HA) is known as a typical representative of the biologically active ceramics the coatings if which on the implant materials is considered as one of the ways of achieving the natural and accelerated bonding to the living tissues. Ceria (CeO₂) is an anti -oxidative and -inflammatory substance material for the application in bio-medical fields the interest towards which is increasing drastically. The attempt to apply those two ceramic nano powders together has never been done before. In the given work, the electrophoretic deposition of HA and CeO₂(separately as well as from the binary solution) was conducted on metallic substrate materials having different conductive properties. As specimens the potential implant alloy of Fe-Cr-Al-RE and a pure Ni mesh were taken. That allowed us to get the data related to the deposition on the flat and high surface area having porous materials as well as that of the ones having different electrical properties: Ni mesh showing outstanding electrical conductivity and thermally pretreated Fe-Cr-Al-RE alloy that formed corrosion protective passivation surface layer of alumina being known as insulating ceramics.

Various deposition parameters were applied and the most appropriate one was selected for our further research purposes. Amongst many different coating deposition techniques available the electrophoretic one is characterized by the simplicity, low price and of course with the coating parameters comparable with the ones obtained by the other commercial rather expensive techniques.

The Figure 1 shows electrophoretically successfully deposited top layer of HA nanoparticles. The microstructure, phase composition and their distribution within the deposited ceramic layers of HA, CeO₂ and HA+CeO₂were carefully studied using scanning electron microscopy, XRD and EDX methods. Some calculations on the to be deposited particles potentials and their deposition parameters were done.

The present work has revealed that electrophoretic deposition of the HA, CeO₂ or HA+CeO₂ nano powder coatings has a strong potential to be widely applied for the bio-medical (and possibly in other) fields.