A new approach for the synthesis of chemically stabilised B-cristobalite-like glass-ceramic materials is developed. It is based on an activated reaction sinter-crystallisation process of compacted powder mixtures at relatively low temperatures and short heat treatment times. To facilitate homogenous dopant distribution and thus the formation of a high content of Bx-cristobalite-like phases, processing a very low thermal expansion coefficient, the batch components are introduced in a chemically, mechanically, or thermally pre-activated form. In this way, the high temperature glass re-melting usually employed in the "classical" synthesis of glass-ceramics is avoided. Using different, mutually complementary techniques of analysis it is revealed that optimal refractory properties are achieved with glass-ceramics containing Xx- and Bx-cristobalite solid solutions with close values of the lattice parameters. In this case, the transformation between these two cristobalite-like solid solutions proceeds instead by a first-order displacive transition. The refractory properties of the glass-ceramic materials thus synthesized and the possibility to use various forming techniques open many fields for their application.
