Study of Structural and Strength Changes in Lithium-Containing Ceramics—Potential Blanket Materials for Nuclear Power, Subjected to High-Dose Proton Irradiation

Abstract

The paper considers the hydrogenation processes in Li2TiO3 ceramics under irradiation with protons with an energy of 500 keV and fluences of 1 × 1010–5 × 1017 ion/cm2. The choice of the type of irradiation, as well as the irradiation fluences, is based on the possibilities of modeling hydrogenation processes and studying the kinetics of structural changes caused by the accumulation of radiation damage. The choice of Li2TiO3 ceramics as objects of research is due to their prospects for using as blanket materials of thermonuclear reactors for the tritium production and accumulation. It was found that the formation of point defects and their subsequent evolution associated with the formation of complex compounds and the filling of pores, followed by the formation of gas-filled bubbles, the presence of which leads to a decrease in crack resistance and resistance to destruction of the near-surface layer. Based on the data on structural changes and evolution of the crystal lattice parameters, its swelling, a description of the destruction processes associated with hydrogenation in Li2TiO3 ceramics was proposed. Also, during the studies, it was found that at irradiation fluences above 1 × 1017 ion/cm2, the appearance of impurity inclusions characteristic of the TiO2 phase was observed, the presence of which indicates the crystal lattice destruction processes because of accumulation of radiation damage and deformations caused by them. Critical doses are established at which there is a sharp deterioration in strength and crack resistance, reflecting the resistance of ceramics to mechanical external influences.

Effects of Composition Variations on Mechanochemically Synthesized Lithium Metazirconate-Based Ceramics and Their Resistance to External Influences

“…Annealing was carried out for 8 h in an air atmosphere, followed by cooling for 24 h with the furnace. The selection of these annealing conditions, encompassing temperature, duration, and cooling process, was informed by prior experimental investigations [26,27], alongside a priori knowledge concerning phase and structural transformations in lithium-containing ceramics derived through mechanochemical or solid-phase synthesis.…”

Synthesis and Structural and Strength Properties of xLi2ZrO3-(1-x)MgO Ceramics—Materials for Blankets

“…The use of lithium ceramics based on titanates, silicates, or zirconates is potentially attractive because of the possibility of producing tritium as a result of nuclear reactions of lithium with neutrons. Moreover, most experts in this field agree that the use of lithium or lithium-containing ceramics will completely solve the problem of tritium fuel for thermonuclear energy, since lithium reserves will last for quite a long time [ 10 , 11 , 12 ]. The creation of blankets based on lithium ceramics must meet a number of requirements, the most significant of which are high mechanical strength and resistance to cracking and destruction under prolonged irradiation or temperature changes, excellent thermal conductivity, and increased resistance to thermal expansion (linear and volumetric) [ 13 , 14 , 15 , 16 , 17 , 18 ].…”