2004

CO2 sensing characteristics were examined in dry condition for Pt, Na2CO3/Na2O-Al2O 3-4SiO2//YSZ/Pt structure. After settled at the working temperature at 460°C, emf was gradually decreased with time and then increased. The drift to decrease the emf observed in the initial period is due to the remove of water in Na2CO3 layer with morphological changes. The diffusion of Na ion in Na2O-Al2O 3-4SiO2 layer to YSZ layer is also one of the reason.

Interactions between β-Al2O3 and a sodium aluminosilicate conductive glass, after thermal treatment at 900 °C, have been investigated on screen-printed gas sensors. Due to the high level of glass additions, the starting powder made of β/β″-alumina, underwent strong compositional modifications. SEM and TEM imaging, coupled with chemical analysis, evidenced the formation of nepheline and α-Al2O3 at the interface between β-Al2O3 and the glass.

The bottom ashes coming from two different municipal solid waste incinerators were vitrified at 1400 _C. The obtained glass, mixed with other wastes coming from metallurgical and mineral industrial wastes, was used as raw material for the production of glass-ceramic tiles. Two different mixtures were used for the tile production: (a) glass from bottom ashes plus corundum-based waste from an aluminum foundry and (b) glass from bottom ashes plus kaolin-based waste from the kaolin ore extraction process.

A protective coating for SiC fiber reinforced borosilicate glass-matrix composites based on zinc borosilicate (ZBS) glass-ceramic was developed. The coating was deposited on the composite surfaces by a simple and cost-effective method, based on slurry dipping followed by a densification and crystallisation stage carried out at optimised temperature and holding time. The coatings were shown to be able to withstand temperatures of up to 700 °C without softening and without exhibiting microcracking.