ABSTRACT

Under direct foaming people understand techniques where a ceramic suspension is directly foamed by incorporating bubbles using mechanical or chemical means. Everyone who was ever involved in the development of ceramic foams knows all too well that the road from unveiling the basic laws of foam stabilization to the manufacture of high quality foam products can be long and stony. An efficient particle stabilization of air bubbles requires partial dewetting of the particles at the air-water interface. Therefore, the in situ hydrophobization technology is applied to partially hydrophobize the surface of the particles directly in suspension by adsorbing short-chain amphiphilic molecules. Owing to the homogeneous microstructure and excellent crack tolerance, the presented foams can readily be machined to high precision. The mechanical characterization of cellular materials as they are obtained from direct foaming processes is a relatively new field in research and development.