This Phase I research is concerned with the development of bioactive coatings on Ti-6AI-4V implant alloy surfaces by an electrochemical procedure. The most widely used method of depositing hydroxyapatite (HA) coatings on implants by plasma spraying uses ionized gas at temperatures of about 1500 degrees Celsius. This high-temperature procedure causes HA to decompose thermally to produce several unwanted phases leading to profound undesired effects on properties of the coating as well as microstructural changes in the substrate causing undesired mechanical property changes. The proposed method involves low temperature operations producing a very pure nanophase HA coatings. Furthermore, the initial surface treatment enhances the bonding of the HA layer onto the substrate. In addition, the deposited coating is designed to produce a porosity gradient in the coating with a desired higher porosity on the top of the coating for better fixation with the bone by osseointegration. Thus, the coating is designed to provide improved bonding at the alloy/coating interface and also at the coating/bone interface. It is anticipated that these novel coatings will result in a much-improved surgical implant end product.
