BARBOSA, S. T. R.; http://lattes.cnpq.br/4885542098738249; BARBOSA, Suzane Thaís dos Reis.
Abstract:
The glass-ceramics have functional properties such as chemical durability and high
mechanical hardness. Based on this, the recycling of sodium-lime glass, typical of
packaging, for the production of glass-ceramics can add value to this material
continuously discarded in the environment. The glasses have an environmental
advantage with regard to their high recycling potential, in addition to the possibility of
being molded into the desired shape, which contributes to various forms of
application. This work had as objectives, the development and characterization of
vitroceramic tablets of considerable aesthetic appeal through the application of
different heat treatments in sodium-calcium glassy residues. As well as, the obtaining
of material with microhardness and impact resistance superior to the precursor glass
as well as the typical glass-ceramic X-ray diffraction pattern. It was also within the
scope of this research, the comparative analysis between the molds used as well as
possibilities of finishing the pieces to improve the visual aspect. Eight granulometric
combinations of vitreous residues and different heat treatments (800oC, 820oC and
840oC) were developed, which resulted in sintering and annealing. The tablets were
characterized by X-ray dispersive energy spectroscopy (EDX), X-ray diffraction
(XRD), Vickers microhardness, impact resistance and optical microscopy. As a result,
the diffractograms indicated a reduction in the halo characteristic of the amorphous
glassy structure and formation of crystalline phases for the amber color. The
microhardness test proved the effectiveness of heat treatments to increase
mechanical hardness in relation to precursor glass. Optical microscopy showed the
beginning of crystallization in the microstructure of the samples. Finally, the sintering
temperature of 840oC, gave the best result regarding the increase of the mechanical
hardness in relation to the precursor glass. Thus, the use of glassy residues was
efficient to obtain glass-ceramics, as well as the combinations of time and
temperature used were satisfactory for improving mechanical properties.
