Produção Nacional
Revisado por pares
Refractory Ceramics of Clay and Alumina Waste
2021; Associação Brasileira de Metalurgia e Materiais (ABM); Associação Brasileira de Cerâmica (ABC); Associação Brasileira de Polímer; Volume: 24; Issue: 2 Linguagem: Inglês
10.1590/1980-5373-mr-2020-0485
ISSN1980-5373
AutoresValmir José da Silva, Salvador K. A. Taveira, Karina Ribeiro Silva, Gelmires de Araújo Neves, Hélio de Lucena Lira, Lisiane Navarro de Lima Santana,
Tópico(s)Advanced ceramic materials synthesis
ResumoRefractory ceramics were produced from clays and alumina waste. Specimens were shaped by uniaxial pressing, subjected to thermal analysis by dilatometry and heat-treated in a conventional furnace at 1300 and 1400ºC, applying a heating rate of 5ºC/min and a dwell time of 2 and 3 hours at the maximum temperature. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and physicomechanical properties. The dilatometric analysis before heat treatment indicated that the formulation containing the largest amount of fluxing oxides presented the highest linear shrinkage. The XRD analysis revealed that mullite was the major phase and needle shaped crystals typical of mullite obtained from clay minerals were observed by SEM. The increase in firing temperature and dwell time at the maximum temperature improved the physicomechanical properties of the specimens. The thermal expansion coefficient (TEC) in the range of 25 to 1000ºC varied from 6.2 to 6.9 x 10-6°C-1.
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