Production characterization of titanium coatings by atmospheric plasma spray (APS) method

Efforts are being made to ensure that materials used in biomedical products can adapt to the tissue when they interact with biological systems and do not cause any side effects. Metallic and ceramic based biomaterials, which are biocompatible, reliable and effective with increasing importance and application area, are used to fulfill or support the functions of organs or tissues in the human body. Titanium and titanium alloys; with its high biocompatibility, high chemical stability, elastic modulus closest to bone structure and low density/high strength properties, it is used extensively in orthopedic and dental applications as an advantageous material for in-body implantation applications. The main purpose of coating methods is to modify the surface of the main material and to give the material properties such as abrasion, corrosion, conductivity and high temperature resistance. Thus, the coating provides the specified properties as well as the properties of the base material can be protected. Plasma spray, is a thermal spray method applied for very high melting coatings. In this process, the electric arc is applied to the nozzle, which acts as the electrode and secondary electrode. The pressurized inert gas (argon, hydrogen, nitrogen, helium) is passed through the electrodes. Gas that reaches a very high temperature turns into plasma form. In the plasma spray coating method, the temperature reaches over 20 000 K and the coating material is delivered to the target material in a speed range of 200-300 m / s to ensure adhesion to the surface. This high temperature produced by plasma brings the coating material to very high temperatures, but the substrate material is not exposed to much heat and there is no change in its microstructure. The aim of this study; metallic titanium coating on metallic implant surfaces other than titanium and increasing the biocompatibility of said materials. In this context, it has been tried to reduce the oxide level of the coatings produced by means of coating parameters which will lead to minimum oxidation of metallic titanium sprayed with plasma spray. The microstructures of the coatings, produced by varying the spray distance and hydrogen flow rate among the spray parameters were characterized.