SINTERIZAÇÃO EM ETAPAS DE NANOCOMPÓSITOS DE ALUMINAZIRCÔNIA

• Ano de defesa: 2011
• Autor(a) principal: Osatchuk, Alexey
• Orientador(a): Chinelatto, Adriana Scoton Antônio
• Banca de defesa: Gelfuso, Maria Virginia , Tebcherani, Sérgio Mazurek
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: UNIVERSIDADE ESTADUAL DE PONTA GROSSA
• Programa de Pós-Graduação: Programa de Pós-Graduação em Engenharia e Ciências de Materiais
• Departamento: Desenvolvimento e Caracterização de Materiais
• País: BR
• Palavras-chave em Português: sinterização em duas etapas; densificação; crescimento de grão e nanocompósitos
• Palavras-chave em Inglês: two-step sintering; densification; grain growth and nanocomposites
• Área do conhecimento CNPq: CNPQ::ENGENHARIAS::ENGENHARIA DE MATERIAIS E METALURGICA
• Link de acesso: http://tede2.uepg.br/jspui/handle/prefix/1405

The ceramic materials have great potential for structural applications because of their have excellent mechanical properties, eg, high hardness, high mechanical strength and resistance to aggressive media. However their low toughness and bending resistance, limiting their range of applications and open interest for researchers for better mechanical properties. Inclusions of nanometric particles in ceramic matrix, called nanocomposites, and the control of ceramic processing, by controlling grain size and densification, can be used for produce ceramic products with higher strength and toughness. One method to control the microstructure that has been studied is the two-step sintering, which has been successfully applied for the densification of nanometric and ultra fine ceramic powders without grain growth. In this work, the two-step sintering of nanocomposite of alumina with 5% volume nanoparticles zirconia was studied. Two proposals in two-step of sintering were studied, of which one consisted to heat the nanocomposite to a high temperature and then rapid cool down to a lower temperature sintering, and on the other proposal was made a step at a temperature below the initiation of densification, followed by heating to the maximum densification rate temperature. The sintering temperature for steps were chosen from constant-heating-rate and conventional sintering. The results showed that the two proposals were efficient to control the grain growth and densification in alumina-zirconia nanocomposites, and, with the sintering in twosteps, it was possible to reduce the grain size up to 70% of the grain size of nanocomposite sintered conventionally.