Ferro, M. C. a, M. H. V. a Fernandas, C. F. M. L. b Figueiredo, M. S. J. G. b Alendouro, and R. C. C. b Monteiro. "
Effect of TiO2 on the crystallization of fly-ash based glass-ceramics."
Materials Science Forum. 455-456 (2004): 831-834.
AbstractA batch of coal fly-ash, soda and lime was melted, quenched to a glass and then devitrified, by one-step heating cycles, forming coarse fibrous microstructures with pores and cracks, resulting in low strength materials. The crystallization behaviour of the based glass was further studied by adding a nucleating agent, TiC2. The resulting structural and microstrutural changes were investigated by differential thermal analysis, scanning electron microscopy, x-ray diffraction, dilatometry and density measurements. The results indicated that the addition of TiO2 could provide a finer grained microstructure, suitable for the production of structural materials.
Ferro, M. C., C. Leroy, R. C. C. Monteiro, and M. H. V. Fernandes. "
Fine-grained glass-ceramics obtained by crystallisation of vitrified coal ashes."
Key Engineering Materials. 230-232 (2002): 408-411.
AbstractCoal fly ashes have been vitrified by melting with Na2O and CaO as fluxing additives. Adequate heat treatments on the fly ash derived glass produced attractive dark green glass-ceramics. These glass-ceramics exhibited fine-grained microstructures consisting of esseneite and nepheline crystals, with average size below 200 nm, homogeneously dispersed in a residual glassy matrix. Several properties, such as density, thermal expansion coefficient, bending strength, hardness and brittleness index were determined and the correlation microstructure-properties is discussed. The results suggest that these coal ash-based glass-ceramics have potential applications as structural materials or as cladding materials.