Andrea Pokorny

Influence of heating rate on the microstructure of glass foams

In the present study, glass foams made of ground soda-lime glass obtained from transparent glass bottles and dolomite were investigated. The objective of this paper was to evaluate the influence of the heating rate on the microstructure of the obtained material and on its properties. The technological characterization of the ceramic bodies involved the determination of the volumetric expansion and average diameter of the pore. The microstructure was investigated by optical microscopy and scanning electron microscopy. Experimental results showed that the heating rate influenced both the volumetric expansion and the average diameter of the pore. Lower heating rates resulted in lower volumetric expansions since more CO2 escaped from within the ceramic body.

Influência da adição de alumina na microestrutura da espuma vítrea (Effects of the alumina addition in the microstructure of foam glass)

In this work, the influence of the alumina addition on the properties of foam glass was studied. Alumina was introduced to the mixture in order to increase the refractoriness of the final product. Ceramic bodies were composed by ground soda-lime glass from transparent glass bottles, dolomitic lime and alumina. The ceramic bodies were formulated with 3 and 5 wt.% of dolomite lime, both without alumina and with 4 wt.% of this material, uniaxially pressed, and fired in the temperature range from 600 oC to 1000 oC at a heating rate of 150 K/h. The technological characterization of the ceramic bodies involved the determination of the volume expansion. The microstructure was investigated by optical microscopy and scanning electron microscopy. The experimental results show that the addition of alumina influenced the volume expansion of the ceramic bodies, decreasing the foaming.