"Mechanical testing of cordierite porous ceramics using high temperature diametral compression"

M.L. SANDOVAL; M. H. TALOU; A. G. TOMBA MARTINEZ; M. A. CAMERUCCI

JOURNAL OF MATERIALS SCIENCE

SPRINGER

Año: 2010 vol. 45 p. 5109 - 5117

0022-2461

In this work, the high temperature mechanical behavior of cordierite porous disks prepared by starch consolidation forming method was evaluated. In this method, based on swelling and gelatinization properties of starch in aqueous suspension at temperature, the starch granules perform as both consolidator/binder of the green body and pore former at high temperature. Aqueous suspensions of talc, kaolin and alumina (29.6 vol.%) with addition of potato or cassava starches (11.7 vol.%) were prepared by intensive mechanical mixing, homogenization and vacuum degasification. Green disks were formed by thermogelling of the aqueous suspensions at 85¢XC for 4h and additional drying at 50¢XC for 24h. They were characterized by bulk density and apparent porosity measurements, and microstructural analysis by SEM/EDAX. Porous cordierite materials were obtained by calcination at 650¢XC for 2h and reactionsintering at 1330¢XC for 4h, employing specific controlled heating schedules in both treatments. Cordierite disks were characterized by bulk density and apparent porosity meaurements, and microstructural analysis by SEM. Mechanical behavior was evaluated in diametral compression using a servohydraulic testing machine at room temperature, 800, 1000 and 1100¢XC. Apparent stress-strain relationships were obtained from load-displacement curves. Mechanical parameters such as fracture strength (ƒãF), apparent Young modulus (Ea) and yield stress (ƒãY) were determined by calculus. Moreover, cracks patterns were also evaluated. The obtained results were analyzed in function of the developed microstructures, considering the presence of a silicate glassy phase and a complex porosity, and the testing temperature. determined by calculus. Moreover, cracks patterns were also evaluated. The obtained results were analyzed in function of the developed microstructures, considering the presence of a silicate glassy phase and a complex porosity, and the testing temperature. determined by calculus. Moreover, cracks patterns were also evaluated. The obtained results were analyzed in function of the developed microstructures, considering the presence of a silicate glassy phase and a complex porosity, and the testing temperature. determined by calculus. Moreover, cracks patterns were also evaluated. The obtained results were analyzed in function of the developed microstructures, considering the presence of a silicate glassy phase and a complex porosity, and the testing temperature. determined by calculus. Moreover, cracks patterns were also evaluated. The obtained results were analyzed in function of the developed microstructures, considering the presence of a silicate glassy phase and a complex porosity, and the testing temperature. determined by calculus. Moreover, cracks patterns were also evaluated. The obtained results were analyzed in function of the developed microstructures, considering the presence of a silicate glassy phase and a complex porosity, and the testing temperature. determined by calculus. Moreover, cracks patterns were also evaluated. The obtained results were analyzed in function of the developed microstructures, considering the presence of a silicate glassy phase and a complex porosity, and the testing temperature. ƒãF), apparent Young modulus (Ea) and yield stress (ƒãY) were determined by calculus. Moreover, cracks patterns were also evaluated. The obtained results were analyzed in function of the developed microstructures, considering the presence of a silicate glassy phase and a complex porosity, and the testing temperature.