Study of the Effect of Two Phases in Li(4)SiO(4)–Li(2)SiO(3) Ceramics on the Strength and Thermophysical Parameters

The paper studies the effect of Li(2)SiO(3)/Li(4)SiO(4) phase formation in lithium-containing ceramics on the strength and thermophysical characteristics of lithium-containing ceramics, which have great prospects for use as blanket materials for tritium propagation. During the phase composition analysis of the studied ceramics using the X-ray diffraction method, it was found that an increase in the lithium component during synthesis leads to the formation of an additional orthorhombic Li(2)SiO(3) phase, and the main phase in ceramics is the monoclinic Li(4)SiO(4) phase. An analysis of the morphological features of the synthesized ceramics showed that an increase in the Li(2)SiO(3) impurity phase leads to ceramic densification and the formation of impurity grains near grain boundaries and joints. During determination of the strength characteristics of the studied ceramics, a positive effect of an increase in the Li(2)SiO(3) impurity phase and dimensional factors on the strengthening and increase in the resistance to external influences during compression of ceramics was established. During tests for resistance to long-term thermal heating, it was found that for two-phase ceramics, the decrease in strength and thermophysical characteristics after 500 h of annealing was less than 5%, which indicates a high resistance and stability of these ceramics in comparison with single-phase orthosilicate ceramics.