Mechanical properties of biocompatible titanium-glass-carbon coatings for application in orthopaedic implants and details for osteosynthesis

In present work, we investigated mechanical properties and phase composition of biocompatible coatings for orthopedic implants, consisting of a titanium sublayer with a developed surface morphology, on which glass-carbon coating was deposited, in order to increase its biocompatibility. The titanium sublayer with thickness 250 µm was deposited using the MPN-004 microplasma spraying equipment. The deposition was performed on substrates with size 10×20×2 mm from Grade 5 Titanium alloy (90 % titanium, 6 % aluminum, 4 % vanadium). The deposition of the glass- carbon coating was accomplished by immersing the samples in a 10 % solution of glassy carbon in toluene, followed by drying and heat treatment at 920 °C in argon. The process was repeated at least 5-7 times or more until a glass-carbon layer with thickness of 19-50 µm was obtained. The mechanical properties of the moderately rough (about 10 µm) and highly rough (more than 100 µm) samples with and without deposited glass-carbon coating were investigated by means of nanoindentation experiments and then compared. An X-ray diffraction analysis of the samples was performed as well. It was found that the deposition of the glass-carbon coating increases not only the biocompatibility of the investigated material, but also leads to improvement of its mechanical properties.