Structure and physical properties of alumina ceramic foams designed for centrifugal infiltration process
Anna J. Dolata, Maciej Dyzia, Zbigniew Jaegermann
Quarterly No. 3, 2017 pages 136-143
DOI:
keywords: alumina foam, structure, physical properties, centrifugal infiltration
abstract In the case of liquid phase processes used for the production of Al alloy matrix composites, the important factors are the interaction on the boundary of the liquid metal-ceramic phase, mainly the wetting of the ceramic surface. From this point of view, in the case of IPCs obtained by centrifugal infiltration, modification of the matrix alloy, the structure and physical properties of the porous ceramic materials, additionally the technological parameters like the temperature and time of infiltration as well as the rotational speed of the mould are important. In turn, the main parameters that influenced the efficiency of the infiltration process are the density, porosity, absorbability and permeability of the porous ceramic medium. The structural characteristics and physical properties of alumina foams, important for the infiltration of liquid aluminum alloy, have been presented. Scanning electron microscopy (SEM) and computer microtomography (μCT) were used to evaluate the microstructure of the Al2O3 foams. Selected properties of the foams such as density, open porosity, total porosity, absorbability were determined. In addition, the Ergun equation to determine the permeability of the foams was used. Metal-ceramic interpenetrating composites (IPCs) were obtained by the centrifugal infiltration of alumina foams with liquid Al alloy.