SILICON CARBIDE CERAMIC FOAM PRODUCED BY DIRECT MICROWAVE HEATING

Abstract

The paper presents results of the research of manufacturing silicon carbide ceramic foam applying the microwave energy as a power source for the heat treatment at very high temperature (up to 1610 ºC). On the other hand, aluminosilicate waste (clay recovered from recycled brick from building demolition as well as coal fly ash) as silica suppliers, has been used to replace some materials such as quartz or sand, with very high silica content. The obtained product had a very high compressive strength (up to 58 MPa), but the porosity had lower values than those obtained from the commonly used raw material. The most important characteristic of the ceramic foam obtained by the nonconventional method is the extremely low specific energy consumption   (maximum 1.42 kWh / kg) required for sintering the raw material at very high temperature, with at least 50% lower than the values obtained by the conventional methods.