Vitroceramic coatings on metallic supports with biomedical applications

Byline: M. Britchi, M. Olteanu, G. Jitianu, M. Branzei, D. Gheorghe, P. Nita Vitroceramic coatings from the oxidic system SiO2-CaO-B2O3-TiO2-R2O (R = Na and K) were applied on metallic supports (titanium and austenitic steels with high Cr and Ni contents). The coating procedure was classical enamelling. The metals were coated by either immersion or by painting over a thin layer from a mixture of frit (having the best composition for each metallic support) with a liquid mixture (triethanol amine ethyl : alcohol = 1 : 10), which was subsequently fired at the enamelling temperature. A good adherence between the two different materials has been thus achieved. Vitroceramic coating - metallic support couples were then characterized by optical microscopy (OM), electronic microscopy (EDS and WDS), and X-ray diffraction (XRD). The adherence of the vitroceramic layers onto metallic supports was tested by microhardness trials at the interface. The processes at the interface, i.e. gas bubble evolution, micropore formation, chemical bonding and diffusion, were evidenced. These coating layers can be employed as both bioactive and biocompatible materials.