High-temperature diametral compression strength of microwave-sintered mullite

Autor(es)

Souto, P. M. ^[1] ; Camerucci, M. A. ^[2] ; Martinez, A. G. Tomba ^[2] ; Kiminami, R. H. G. A. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Carlos, Dept Engn Mat, BR-13560 Sao Carlos, SP - Brazil

^[2] Consejo Nacl Invest Cient & Tecn, INTEMA, Lab Mat Estruct, Div Ceram, Mar Del Plata, Buenos Aires - Argentina

• Tipo de documento: Artigo Científico
• Fonte: Journal of the European Ceramic Society; v. 31, n. 15, p. 2819-2826, DEC 2011.
• Citações Web of Science: 6

Resumo

The mechanical strength of mullite materials sintered by the conventional route or by microwave was evaluated by diametral compression at room temperature and 1400 degrees C. Crack patterns and fracture mechanisms were analyzed and the results were discussed in terms of the final microstructures. The conventional and microwave sintered materials showed similar densification degrees and homogeneous microstructures with small equiaxial grains. Independent of the sintering route, the fracture strength did not change as the temperature increased. However, the mechanical strength of microwave sintered mullite was always higher than the conventionally sintered materials. Moreover, in both mullite materials, microcracks produced by the effects of thermal expansion and/or elastic anisotropies during sintering and/or mechanical testing were critical defects. In the early steps, microcracks occurred in transgranular mode. However, upon approaching the critical condition, their propagation was more intergranular until they coalesced and the specimen failed, generally in a triple-cleft fracture. (C) 2011 Elsevier Ltd. All rights reserved. (AU)

• Processo FAPESP: 07/59564-0 - Desenvolvimento de nanoestruturas cerâmicas em forno de microondas
• Beneficiário: Ruth Herta Goldschmidt Aliaga Kiminami
• Modalidade de apoio: Auxílio à Pesquisa - Regular