DEMAT - Departamento de Engenharia de Materiais
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Article Avaliação da potencialidade de argilas do Rio Grande do Norte, Brasil. Parte-II: propriedades tecnológicas(Cerâmica Industrial, 2008) Dutra, Ricardo Peixoto Suassuna; Silva, Jaquelígia Brito da; Varela, Marcio Luiz; Nascimento, Rubens Maribondo do; Gomes, Uílame Umbelino; Paskocimas, Carlos AlbertoArticle Development of composite material from tire scrapes and latex for application in thermal insulation(Engenharia Térmica, 2009-12) Nascimento, Rubens Maribondo do; Ford, Elmo Thiago Lins Couras; Mendes, J. U. L.; Pereira, C. M. C.; Marques, A. T.Article Influência da gipsita no surgimento de eflorescência em telhas cerâmicas(Cerâmica Industrial, 2009-08) Nascimento, Rubens Maribondo do; Monteiro, Celina Margarida de Oliveira Lima; Martinelli, Antonio EduardoArticle Desenvolvimento de formulações de massas para a indústria de cerâmica vermelha do Rio Grande do Norte(ABCERAM, 2006) Dutra, Ricardo Peixoto Suassuna; Araújo, Pedro Alighiery Silva de; Macedo, Rose Meire Penha Rovoredo de; Nascimento, Rubens Maribondo do; Gomes, Uílame Umbelino; Martinelli, Antonio Eduardo; Paskocimas, Carlos AlbertoArticle A minimização dos impactos ambientais causados pela produção de cerâmica vermelha com utilização da análise racional para formulações de massa(ABCERAM - Associação Brasileira de Cerâmica, 2006-09) Vale, Sancha Adelia de Lima; Varela, M. L.; Dutra, R. P. S.; Nascimento, Rubens Maribondo do; Paskocimas, Carlos Alberto; Formiga, Fábio RochaArticle Síntese de Manganita de Lantânio com substituição parcial do La por Sr pelo método citrato(Rede Latino-Americana de Materiais, 2007) Silva, Walquíria Joseane da; Melo, Dulce Maria de Araújo; Soares, Sibelle Feitosa da Cunha X.; Pimentel, Patrícia Mendonça; Nascimento, Rubens Maribondo do; Martinelli, Antonio Eduardo; Rabelo, Adriano AlvesLanthanum manganite is a type p intrinsic semiconductor ceramic oxide with perovskite structure. The partial substitution in A-site of that material increases it’s electrical conductivity, becoming appropriate to be used in production of solid oxide fuel cells (SOFC) component for working at temperatures around at 1000 °C. In general, the properties of materials change with composition and synthesis method. In the present work, the synthesis of La1-xSrxMnO3 (x = 0,20-0,22) has been carried out by citrate method, aiming at to investigate the percentage effect of the dopante in the formation of the perovskite phase. This method allows to obtain homogenous powders and crystalline phase in lower temperatures than traditional methods of synthesis. The sample was characterized by X-ray diffraction (XRD), thermal gravimetric analyses (TGA), scanning electron microscopy (SEM) and analysis by specific surface area by BET method. The powders synthesized with 22% partial substitution of strontium showed better results relative to obtain perovskite phaseArticle Efeito da condensação e queima na formação de defeitos microestruturais em cerâmicas feldspáticas dentárias(ABCERAM, 2007) Souza, Júlio Cesar Matias de; Nascimento, Rubens Maribondo do; Martinelli, Antonio EduardoFeldspar-based dental ceramics joined to metallic substructures are frequently used for unitary or extensive dental prosthetic restorations. As the manufacturing technique significantly affects the performance of dental ceramic restorations, the aim of this study was to evaluate the effect of multiple firing cycles and compaction method on the formation of microstructural defects in feldspar-based dental ceramics. Commercial powders of two dentin feldspar-based ceramics (A and B) were characterized by XRD and particle size distributions. After that, ceramic samples were produced by compaction without ultrasonic vibration and fired once, compaction with ultrasonic vibration and fired once, and finally, compaction with ultrasonic vibration and fired four times. The fired materials were ground and polished, characterized by SEM-EDS and optical microscopy. A hot-pressed feldspar-based ceramic (C) was used for comparison purpose. The XRD analysis showed the presence of leucite as the only crystalline phase. The particle size distributions of both ceramics tested were trimodal with the presence of larger particles in B ceramic. The microstructural analysis revealed the presence of pores in the fired ceramics. The volume of pores was larger in the compacted samples without ultrasonic vibration. The samples submitted to four firing cycles had a smaller number of pores, however, with the presence of cracks generated during cooling because of differences in thermal expansion coefficients. Therefore, the results showed that the adequate compaction and firing procedure involved ultrasonic vibration followed by firing once, which provides microstructural characteristics similar to hot-pressed ceramicsArticle Interface microstructure of alumina mechanically metallized with Ti brazed to Fe–Ni–Co using different fillers(Elsevier, 2007-09-25) Nascimento, Rubens Maribondo do; Martinelli, Antonio Eduardo; Buschinelli, Augusto José de Almeida; Sigismund, EgonArticle Dilatometric behavior and microstructure of sintered Fe–NbC and Fe–TaC composites(Springer, 2006-12-16) Martinelli, Antonio Eduardo; Paulo, Domingos Sávio de Araújo; Nascimento, Rubens Maribondo do; Távora, Michele Portela; Gomes, Uílame Umbelino; Alves Júnior, ClodomiroArticle Uso da técnica de dilatometria no estudo do efeito da adição de resíduo de caulim na massa de porcelanato(Associação Brasileira de Cerâmica - ABCERAM, 2008-11) Formiga, Felipe Lira; Araújo, Pedro Alighiery Silva de; Dutra, Ricardo Peixoto Suassuna; Varela, Márcio Luiz; Nascimento, Rubens Maribondo do; Paskocimas, Carlos Alberto