Ceramic samples based on Si3N4 were obtained and studied using a sintering additive in the MnO-TiO2 system of eutectic composition, which was accepted and applied to the surface of silicon nitride by the sol-gel method. Ceramic samples were obtained by hot pressing at 1650 °C and 1750 °C. Phase composition, thermo-physical and mechanical properties were studied. The microstructure of the resulting ceramics was also studied.