Cohesive or adhesive hydroxylapatite layers deposited by ArF laser ablation

The article presents the results of macroscopic examination of adhesion of hydroxyapatite layers deposited by the PLD method on nitrided substrates made of Ti-Al-4V alloy. The layers were deposited by means of the ArF laser, in vacuum at p ~ 3 x 10-5 Torr, after deposition layers were annealing during the period of 90 minutes, at the temperature of 600°C. The research of the deposited layer topography and the topography of tested layers were carried out by means of the atomic force microscope. The comparative examination showed that the mechanical resistance of the deposited layers depends not on their adhesion to the substrate, but on the cohesion of the deposited material. The most damage-resistant layers proved to have the thickness of the order of several hundred nanometers, as they are still influenced by the forces of adhesion to the substrate. The plasticity characteristic for such layers is similar to the plasticity of the substrate. The deposited layers, both amorphous and polycrystalline were characterized by columnar structure.© (2004) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.