abstract
Glass-ceramics in the diopside (CaMgSi(2)O(6))-fluorapatite (Ca(5)(PO(4))(3)F)-wollastonite (CaSiO(3)) system are potential candidates for restorative dental and bone implant materials. The present study describes the influence of varying SiO(2)/CaO and CaF(2)/P(2)O(5) molar ratio on the structure and thermal behavior of glass compositions in the CaO-MgO-SiO(2)-P(2)O(5)-Na(2)O-CaF(2) system. The structural features and properties of the glasses were investigated by nuclear magnetic resonance (NMR), infrared spectroscopy, density measurements and dilatometry. Sintering and crystallization behavior of the glass powders were studied by hot-stage microscopy and differential thermal analysis, respectively. The microstructure and crystalline phase assemblage in the sintered glass powder compacts were studied under non-isothermal heating conditions at 825 degrees C. X-ray diffraction studies combined with the Rietveld-reference intensity ratio (R.I.R) method were employed to quantify the amount of amorphous and crystalline phases in the glass-ceramics, while scanning electron microscopy was used to shed some light on the microstructure of resultant glass-ceramics. An increase in CaO/SiO(2) ratio degraded the sinterability of the glass powder compacts, resulting in the formation of akermanite as the major crystalline phase. On the other hand, an increase in P(2)O(5)/CaF(2) ratio improved the sintering behavior of the glass-ceramics, while varying the amount of crystalline phases, i.e. diopside, fluorapatite and wollastonite. (C) 2010 Published by Elsevier Ltd. on behalf of Acta Materialia Inc.
keywords
CAO-MGO-SIO2 SYSTEM; BIOACTIVE GLASSES; IN-VITRO; ADDITIVES; SPECTROSCOPY; CELLS; CAF2; P2O5; B2O3; NA2O
subject category
Engineering; Materials Science
authors
Kansal, I; Tulyaganov, DU; Goel, A; Pascual, MJ; Ferreira, JMF
our authors
José Maria da Fonte Ferreira
Retired Professoracknowledgements
I.K. is indebted to CICECO and University of Aveiro for the research grant. A.G. is grateful to FCT-Portugal for a research grant (SFRH/BPD/65901/2009). The authors also thank Dr. Robert V. Law, Imperial College London, for fruitful discussions regarding the NMR results.