Contribution of Cerium Dioxide to the Crystallization and Bioactivity Performance of some Silicate glass-ceramics
S.M.Salman*, S.N.Salama, H.Darwish, and Ebrahim A.Mahdy
National Research Center, Giza
The study of crystallization characteristics, micro-hardness chemical durability , and bioactivity performance (in-vitro) of glass-ceramics based on the CaO-MgO-P2O5-CaF2-SiO2 system with different amounts of CeO2 is considered in the present work. The investigation was done by means of differential thermal analysis (DTA), X-ray diffraction analysis (XRD), energy dispersive X-ray analysis (EDAX), scanning electron microscopy(SEM), Vicker’s micro-hardness indenter, weight loss technique. Bioactivity of the glass-ceramics was investigated in-vitro by examining apatite layer formation on the surface of glass-ceramics treated in simulated body fluid (SBF) with ion concentrations nearly equal to those in human blood plasma. The main crystalline phases, formed after controlled heat-treatment of the glass, were diopside, wollastonite solid solution and fluoroapatite. The addition of different amount of CeO2 in the glass led to the formation of cerium silicate phase which has increased by the addition of CeO2. The bioactivity performance and chemical durability of the glass ceramic were improved by further CeO2 addition. The Vicker’s micro-hardness values of the resulting glass ceramics were: (5837-5353 MPa). The obtained data was correlated to the type of the crystalline phases formed and the resulting micro-structure. Keywords: Glass; Crystallization; Glass Ceramic; Bioactivity; Micro-hardness; Chemical durability.