Obtaining glass ceramics of the MgO–SiO$_2$ system by the plasma melting method

Results of experimental studies of the synthesis of glass ceramics of the MgO–SiO$_2$ system by plasma melting at the atmospheric pressure are presented. Electron microscopy data showed that, during the melt crystallization with the rate of 287 $\pm$ 5 K/s, the surface morphology is represented by a dense packing of rhombic dodecahedral Mg$_2$SiO$_4$ crystals (without open porosity). In this case, the matrix is characterized by the formation of a dense framework with a clear linear arrangement of spherical inclusions corresponding to the MgSiO$_3$ phase. As a result of the plasma melting synthesis, glass ceramics with the density of 3.56 g/cm$^3$ and microhardness of up to 15 GPa was obtained. It is assumed that glass ceramics with such a composition can be considered as an excellent option for the development of a cost-effective high-quality refractory.