INVESTIGADORES
TOMBA MARTINEZ Analia Gladys
artículos
Título:
“High temperature diametral compression strength of microwave sintered mullite”
Autor/es:
P.M. DE SOUTO; M.A. CAMERUCCI; A.G. TOMBA MARTINEZ; , R.H.G.A. KIMINAMI
Revista:
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
Editorial:
ELSEVIER SCI LTD
Referencias:
Año: 2011 vol. 31 p. 2819 - 2826
ISSN:
0955-2219
Resumen:
The mechanical strength of mullite materials sintered by the conventional route or by microwave was evaluated by diametral compression at room temperature and 1400 ◦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. 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.