Preparation and properties of enstatite ceramic foam from talc

The effective method of preparation, stabilization and high temperature treatment of enstatite ceramic foam is described in this work. The technique is based on foaming of suspension of talc, on the stabilization of foam structure and on final high temperature treatment after drying. The spontaneous delamination of aggregates and the redistribution of talc particles in foam are driven by decreasing surface energy. The changes of phase composition as well as the mechanism and the kinetics of processes which take place during the thermal treatment were described. The treatment within the temperature range from 1150 to 1250 °C provides the ceramic foam via sintering without melted phase, whereas a liquid phase sintering occurs at higher temperatures. The final temperature of sintering is 1300 °C. Increasing amount of melted phase supports the formation of enclosed porosity and formed glass stabilizes the high temperature protoenstatite polymorph in the foam.