SciELO - Scientific Electronic Library Online

vol.48 número306The role of properties evaluated as a function of temperature in the simulation of the thermomechanical behavior of refractory ceramicsThe hot wire method: the hot wire parallel technique and the hot wire surface technique índice de autoresíndice de materiabúsqueda de artículos
Home Pagelista alfabética de revistas  

Servicios Personalizados




Links relacionados



versión impresa ISSN 0366-6913versión On-line ISSN 1678-4553


ORTEGA, F. S.; INNOCENTINI, M. D. M.; VALENZUELA, F. A. O.  y  PANDOLFELLI, V. C.. Effect of aeration technique on the macrostructure and permeability of gelcast ceramic foams. Cerâmica [online]. 2002, vol.48, n.306, pp.79-85. ISSN 0366-6913.

The production of porous ceramics through the aeration of suspensions associated with the gelcasting process provides cellular porous ceramics with excellent properties and a wide range of densities. Nonetheless, the use of this material in applications such as filtering, thermal insulation, or catalyst supports requires a macrostructural tailoring in order to favor specific properties, such as permeability, thermal conductivity or specific surface area. These properties are determined by characteristics such as density, pore size distribution and connectivity between neighboring cells, which are defined during foam formation. The aim of this work was to assess the influence of the aeration process on the macrostructure of ceramic foams. A planetary mixer and a stirring vessel with a bubbling ring at the bottom surface were studied in this work. Alumina suspensions containing different foaming agent concentrations were submitted to mixing cycles in both foam generators. After gelling, samples were sintered and had their pore size distribution evaluated using image analysis and mercury porosimetry. The air permeability was also evaluated. The results showed that the aeration process may strongly influence the density and the mode pore size, having a significant effect on the material's permeability. It was observed that mercury porosimetry and image analysis lead to different pore size distributions. However, both results are useful, depending on the aim of the analysis.

Palabras clave : porous ceramics; ceramic foam; gelcasting; aeration; permeability.

        · resumen en Portugués     · texto en Portugués     · Portugués ( pdf epdf )


Creative Commons License Todo el contenido de esta revista, excepto dónde está identificado, está bajo una Licencia Creative Commons