TEXTURE AND MICROSTRUCTURE OF HAp THIN LAYERS ON Ti6Al4V

A new biocompatybile HAp/TiN multilayer coatings were developed by a multiplex technology comprising glow discharge nitriding and pulsed laser deposition. Glow discharge method was used to fabricate TiN interlayer on the Ti6Al4V substrate. Alternately depositing TiN and HAp layers on Ti6Al4V substrates applied to prevent direct contact of the human tissue with metallic substrates. Coatings bioinert implants with bioactive hydroxyapatite ceramics offers a potential for biological interaction between the bone and the coated implant, which enables positive biological/chemical material connections. With the objective of producing a new generation of biomaterials, titanium alloys submitted to glow discharge nitriding were used as a substrate for hydroxyapatite coating, deposited by the pulsed laser deposition method. Hydroxyapatite (HAp) layers were deposited at 250DGC by means of the Nd-YAG laser (A = 1064nm) working at the repetition of 10Hz. Stoichiometry of the HAp target was generally transferred to the Ti6Al4V/TiN substrate. However, a respectively high volume fraction of amorphous phase was formed due to not high enough temperature for full crystallization (250DGC) which was stated on the basis of XRD examinations. Contribution of the gas flow in the reactive chamber was stated in relation to the observed crystallographic texture. The performed AFM studies revealed that the high level of crystallization has been obtained when oxygen was introduced into the reactive chamber.