Preparation and Characterisation of Biocompatible Vitroceramic–Metal Systems for Applications in Medicine

Vitroceramic coatings from the oxide system SiO₂–CaO–Na₂O–B₂O₃-TiO₂ were obtained on metallic supports (titanium and austenitic steels with high Cr and Ni contents). The coating technology was classical enamelling. The metallic support is coated by either immersion or painting with a slurry layer resulting from a mixture of a frit (having the best oxide composition for each metallic support) with a liquid, fired at the enamelling temperature and then subjected to a thermal treatment for crystallisation. Good adherence between the two different materials is achieved when their thermal expansion coefficients are close to each other. The vitroceramic coating–metallic support system was characterised by optical microscopy, SEM, and X-ray diffraction. The adherence of the vitroceramic layer to the metallic supports was determined using microhardness tests carried out at the interface. Evidence of the processes occurring at the interface (gas bubbles, micropores, chemical binding, etc.) was also found. The coating layers are types of biocompatible and bioactive vitroceramic materials.