Next Article in Journal
Continuous Emotion Recognition for Long-Term Behavior Modeling through Recurrent Neural Networks
Next Article in Special Issue
Laboratory Study on the Water-Soluble Polymer as a Self-Curing Compound for Cement Concrete Roads in Ethiopia
Previous Article in Journal
A Comparative Analysis on Suicidal Ideation Detection Using NLP, Machine, and Deep Learning
Previous Article in Special Issue
Mechanical Properties of Sustainable Metal Matrix Composites: A Review on the Role of Green Reinforcements and Processing Methods
 
 
Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
Journals
Technologies
Volume 10
Issue 3
10.3390/technologies10030058
technologies-logo
Submit to this Journal Review for this Journal Propose a Special Issue
► Article Menu

Article Menu

share Share announcement Help format_quote Cite question_answer Discuss in SciProfiles thumb_up
...
Endorse textsms
...
Comment
first_page
settings
Order Article Reprints
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

Study of Structural, Strength, and Thermophysical Properties of Li2+4xZr4−xO3 Ceramics

by
Artem L. Kozlovskiy
1,2,3,*,
Bauyrzhan Abyshev
3,
Dmitriy I. Shlimas
1,3 and
Maxim V. Zdorovets
1,3
1
Laboratory of Solid State Physics, The Institute of Nuclear Physics, Almaty 050032, Kazakhstan
2
Institute of Geology and Oil and Gas Business, Satbayev University, Almaty 050032, Kazakhstan
3
Engineering Profile Laboratory, L.N. Gumilyov Eurasian National University, Nur-Sultan 010008, Kazakhstan
*
Author to whom correspondence should be addressed.
Technologies 2022, 10(3), 58; https://0-doi-org.brum.beds.ac.uk/10.3390/technologies10030058
Submission received: 10 March 2022 / Revised: 29 April 2022 / Accepted: 6 May 2022 / Published: 10 May 2022
(This article belongs to the Special Issue Commemorative Issue in Honor of Prof. Dr. Manoj Gupta on the Occasion of 60th Birthday)
Browse Figures
Versions Notes

Abstract

:
The work is devoted to the study of technology that can be used to obtain lithium-containing ceramics of the Li2+4xZr4−xO3 type using the method of solid-phase synthesis combined with thermal annealing at a temperature of 1500 °C. A distinctive feature of this work is the preparation of pure Li2ZrO3 ceramics with a high structural ordering degree (more than 88%) and density (95–97% of the theoretical density). During the study, it was found that a change in the content of initial components for synthesis does not lead to the formation of new phase inclusions; however, an increase in the LiClO4·3H2O and ZrO2 components leads to changes in the size of crystallites and dislocation density, which lead to the strengthening of ceramics to external mechanical influences. The results of the measurements of thermophysical characteristics made it possible to establish that the compaction of ceramics and a decrease in porosity lead to an increase in the thermal conductivity coefficient of 3–7%.

1. Introduction

One of the important tasks in nuclear energy, set by the International Atomic Energy Commission, is the search for alternative ceramics to the main type, Li4SiO4 ceramics, which are used as tritium breeder materials in new-generation reactors, particularly in helium-cooled pebble-bed reactors [1,2,3]. The search for alternative materials is associated with expanding the capabilities of materials such as blankets, as well as studying the possibilities of increasing the production of tritium in the reactor itself due to transmutation reactions of the 6Li + n → He + T type and its subsequent accumulation [4,5]. At the same time, it is worth considering the fact that the short lifetime of tritium, due to rapid radioactive decay, makes its shelf life extremely limited, which leads to the need for constant reproduction of tritium in a thermonuclear reactor.
One of the ways to solve this problem is the use of lithium-containing ceramics as blanket materials, which are placed in the reactor walls for the continuous reproduction of tritium and the maintenance of thermonuclear reactions [6,7,8]. In this case, the ceramic material is subjected to continuous irradiation, accompanied by thermal heating and the accumulation of radiation damage associated with transmutation reactions, the main products of which are tritium and helium [9,10]. In turn, the accumulation of helium in the structure can lead to gaseous swelling of the near-surface layer of ceramics, the accumulation of stresses, and the deformations of the structure, which can subsequently lead to a decrease in strength and thermal characteristics [11,12,13,14]. In this regard, additional requirements are imposed on lithium-containing ceramics, related to their resistance, that is, requirements not only related to their radiation resistance to helium swelling processes but also to their resistance to mechanical and thermal loads that may occur during operation.
Moreover, one of the selection criteria for lithium-containing ceramics is the choice of the oxide component, which plays an important role in determining the structural characteristics of ceramics. In particular, one of the alternative materials to classical lithium-containing ceramics of the Li4SiO4 type is lithium zirconate (Li2ZrO3)-based ceramics, which have high mechanical strength; resistance to corrosion and radiation damage; and high compatibility with various materials, which opens up prospects for their application as materials for blankets [15,16,17]. As is known, the main factor influencing the rate of tritium release as a result of nuclear reactions is the microstructure of ceramics, which depends not only on the choice of ceramic type but also on the conditions for their production.
The most common method to obtain Li2ZrO3 ceramics is the method of thermal fusion of lithium carbonate (Li2CO3) and zirconium dioxide (ZrO2) at high temperatures (over 700 °C), although in a number of works, it is indicated that this method is accompanied by the production of ceramics containing amorphous inclusions, as well as impurities in the form of undissolved ZrO2 or transitional phases of the Li6Zr2O7 type [18,19,20]. At the same time, if the presence of the ZrO2 impurity phase, as a rule, is due to an excess of the initial powders used for synthesis, then the formation of the Li6Zr2O7 phase may be associated with the appearance of heterogeneities in the composition, leading to local variations in stoichiometry [21]. One of the alternative options for the synthesis of lithium-containing ceramics is the replacement of Li2CO3 with LiClO4·3H2O, which makes it possible to obtain pure ceramics at high temperatures due to accelerated melting processes.
One of the ways to reduce the concentration of impurities is the doping of ceramics with various oxides, which leads to a decrease in the sintering temperature but, at the same time, is accompanied by the formation of two–three-phase ceramics [22,23,24,25], which have also found their application in view of the possibility of increasing the productivity of tritium release, as well as an increase in resistance to external mechanical influences. Moreover, in a number of works, it was noted that the presence of two phases leads to an increase in the resistance of ceramics to external influences, including radiation damage [26,27].
Despite a fairly large number of scientific studies aimed at studying the properties of Li2+4xZr4−xO3 ceramics, as well as the methods for their production, there are still many questions related to the formation of the ceramic structure and ways to get rid of impurities, as well as an increase in the lithium content in the ceramic structure, which plays a key role in the further practical application of ceramics. In this regard, the main purpose of this work was to study the structural ordering processes, as well as the mechanical and heat-conducting properties of Li2ZrO3 ceramics obtained by solid-state synthesis followed by thermal sintering at a temperature of 1500 °C, depending on the concentration of components in the composition of ceramics. At the same time, the features of this work that distinguish it from previous studies are as follows: Firstly, based on the results of previous studies [28], as well as a number of other studies, the annealing temperature was chosen to be much higher than (1500 °C instead of 900–1100 °C) that used in most studies, the choice of which was determined by the possibilities of the thermal annealing of defects and impurity inclusions arising during thermal sintering at temperatures below 1000 °C. Secondly, a change in the concentration of the xLiClO4·3H2O and (1−x)ZrO2 components from x = 0.1–0.5 made it possible to evaluate the change in the properties of ceramics with different lithium content in the structure, as well as its effect on the structural, mechanical, and strength properties of ceramics.
The interest in this class of ceramics is due to their great prospects for use as nuclear materials for breeders for the purpose of breeding tritium, as well as the production of nuclear fuel and the maintenance of thermonuclear reactions. The use of oxide ceramics as nuclear materials is associated with radiation damage processes, which, as is known from the literature [29,30,31,32,33], can have a significant effect on the preservation of material properties, including strength characteristics and thermophysical parameters [29,30,31,32,33].

2. Experimental Section

LiClO4·3H2O and ZrO2 powders, purchased from Sigma Aldrich (Saint Louis, MO, USA), were chosen as initial reagents for synthesis; the powder sizes were no more than 1 μm, and their chemical purity was 99.95%.
The synthesis of ceramics was carried out using the method of mechanochemical synthesis, combined with thermal annealing of the resulting ground mixtures at an annealing temperature of 1500 °C. The synthesis was carried out by varying the content of the components xLiClO4·3H2O and (1−x)ZrO2, where x = 0.1–0.5 in order to determine the effect of changes in the concentration of the components on the structural parameters and phase composition of the studied ceramics. The grinding of samples after weighing was carried out in a PULVERISETTE 6 planetary mill (Fritsch, Germany) under the following conditions: grinding speed 400 rpm and grinding time 1 h. Thermal annealing was carried out in a muffle furnace at a temperature of 1500 °C for one hour; the heating rate was 10 °C/min, and the cooling time was 24 h.
Figure 1 shows a schematic representation of the main processes used to obtain lithium-containing ceramics, including component weighing, mechanochemical grinding, and subsequent thermal sintering at specified parameters.
The study of the structural parameters, as well as the phase composition of the synthesized ceramics, was carried out using the method of X-ray diffraction phase analysis. The diffraction patterns were taken in Bragg–Brentano geometry on a D8 Advance ECO powder diffractometer (Bruker, Germany). The recording conditions were as follows: 2θ = 25–75°, step 0.03°, and spectrum acquisition time at the point 1 s. An analysis of the structural parameters was carried out using the DiffracEVA v.4.2 program code, the phases were determined using the full-profile Rietveld method, and the phases were refined using the PDF-2 (2016) database.
The determination of ceramic density was carried out by analyzing changes in crystal lattice volume with further application of the obtained data in Formula (1):
p = 1.6602 ∑ A Z V o ,
where Vo is the crystal lattice volume depending on the composition of the ceramics, Z is the number of atoms in a crystal cell, and A is the atomic weight of atoms.
The crystallite sizes were determined using the Scherrer method, which is based on the determination of the FHWM value depending on the angular position of the diffraction maxima.
The dislocation density was estimated using Formula (2):
δ = 1 L 2
where L is the crystallite size, determined using the Scherrer method, taking into account the contribution of reflection shape distortions.
The crystallinity degree was determined by calculating the ratio of the diffraction reflection areas to the background radiation area, which is characteristic of disordered regions in the ceramic structure.
The study of strength properties was carried out using two methods. The determination of hardness was carried out using the indentation method, which was implemented using a LECO LM 700 microhardness tester (LECO Corporation, Saint Joseph, MI, USA). A Vickers pyramid was used as an indenter, with an indenter load of 10 N.
Resistance to single compression was determined by testing the compression of samples in a press with a compression rate of 0.1 mm/min. The resistance limit was defined as the maximum pressure that the sample could withstand until cracking and partial destruction.
The study of the thermo-physical properties of the ceramics was carried out using the method of determining the temperature difference with a longitudinal heat flux through the sample during heating. The thermal conductive characteristics were evaluated using Formula (3), which makes it possible to determine the thermal conductivity coefficient.
λ = q δ t c 1 − t c 2 ,
where q is the heat flux density, W/m2; tc1 and tc2 are the temperatures on both sides of the sample, K; and δ is the thickness of the sample, m. The temperature difference was measured using a KIT-800 instrument (Moscow, Russia).

3. Results and Discussion

Figure 2 shows the results of the X-ray diffraction phase analysis of the studied ceramics regarding the concentration of the components. A full-profile analysis of the obtained diffraction patterns made it possible to establish that the main reflections are characteristic of the Li2ZrO3 monoclinic phase (PDF-01-070-8744) with C2/2(15) spatial syngony. According to the results in [28], thermal annealing at temperatures above 900 °C leads to the displacement of LiO and ZrO2 impurity phases from the ceramic structure, and a further increase in the annealing temperature leads to the ordering of the structural parameters (lattice parameter and crystallinity degree) and a change in the grain size associated with their coarsening and increase in density. An analysis of the obtained diffraction patterns indicated that a change in the component concentrations in the composition of the ceramics, as well as subsequent thermal annealing, does not lead to the formation of new phases, as evidenced by the absence of new reflections in the diffraction patterns. Unlike commercial samples of Li2ZrO3 ceramics, in the structure of which, according to the data in [18], the presence of impurity phases of the initial ZrO2 and Li2CO3 powders was observed, impurity inclusions were not found in the studied samples obtained at a temperature of 1500 °C. At the same time, the data of a comparative analysis of the areas of diffraction reflections and background radiation indicate a high crystallinity degree of the samples (more than 85%), which varies depending on the content of the components. Moreover, the content of ZrO2 impurity inclusions in the structure of Li2ZrO3 ceramics was reported in [19], the presence of which is due to manufacturing processes. Moreover, in most known works [20], thermal sintering occurs at temperatures of 700–1100 °C. The main changes in the diffraction patterns are mainly associated with changes in the intensity of reflections and their width; this is characterized by a change in the size of crystallites, as well as a shift of reflections to the region of large angles, which is typical for a change in crystal lattice parameters. For comparison, the changes in the main reflections and their positions are presented, according to which, an increase in the concentration of the LiClO4 component in the initial mixture leads to a decrease in the intensity of reflections and their shift. At the same time, the greatest changes are observed for ceramics with a content of x = 0.4–0.5. Such a shift may be due to the substitution of zirconium ions (13.9 Å), which have a radius larger than that of lithium ions (7.1 Å). An increase in the lithium concentration in the structure, in turn, does not lead to the formation of impurity phases, and a decrease in the intensity of reflections and a change in their width (FWHM) indicate changes in the size of crystallites and their fragmentation, which, in turn, lead to an increase in the dislocation density due to an increase in grain boundaries. A change in the positions of reflections, including their shift to the large angle region, as is known, leads to a decrease in crystal lattice parameters, which can be due to several factors: the processes of substitution of atoms of one type for atoms of another type; the deformation processes of crystal lattice compression, leading to its compaction; and relaxation processes associated with changes in point defect concentration in the composition of ceramics as a result of external influences. It is also worth noting that the change in the crystal lattice parameters may be due to the effect associated with a change in the component concentration of O-vacancies. An increase in the lithium concentration in the structure can also lead to the formation of additional vacancy defects, which are formed as a result of the partial breaking of Zr-O chemical bonds. In this case, part of the free oxygen can be displaced from the structure during thermal annealing.
When estimating the shape of the diffraction reflection lines, it was determined that deformation effects associated with the structure distortion make a very small contribution to the change in structural parameters (no more than 5–10% according to the Williamson–Hall method), and the change in the shape of reflections is mostly due to size effects, leading to a change in the dislocation density.
Relaxation processes also do not make a large contribution to the change in structural parameters, since the crystallinity degree does not increase with changes in component concentrations, but it has a slight downward trend, which indicates the absence of defect annealing processes.
Based on this, it was assumed that the main changes in diffraction reflections associated with a maxima position shift to the large angle region are due to the effects of the substitution of zirconium ions by lithium ions in the lattice sites with an increase in the lithium-containing component concentration in the ceramic during its synthesis.
Table 1 presents the results of evaluating the structural parameters, as well as the crystallinity degree of the samples under study. It can be seen from the data presented that an increase in the X component content leads to a decrease in the crystal lattice parameters. However, a change in the crystal lattice parameters leads to a slight decrease in the structural ordering degree, which may be due to the partial replacement of zirconium ions by lithium ions at the lattice sites, as well as the fragmentation of crystallites, the size of which also decreases. In turn, a decrease in the size of crystallites leads to an increase in the dislocation density, which plays an important role in increasing the strength properties.
Figure 3 shows the assessment results of changes in the crystal lattice parameters depending on the X component concentration in comparison with the reference values of the parameters for the Li2ZrO3 phase (PDF-01-070-8744) (a0 = 5.42660 Å, b0 = 9.03100 Å, c0 = 5.42270 Å, β0 = 112.720°, and V0 = 245.13 Å3).
The results of changes in the structural parameters (Figure 3) for high annealing temperatures are in good agreement with the results in [34], according to which, at high annealing temperatures, an anisotropic change in the crystal lattice parameters was observed due to thermal effects, as well as the difference in cationic radii. In this case, changes in the parameter a depending on the content of the component have an isotropic nature of distortions, while the parameters b and c change anisotropically, which may be due to the difference in the filling of lattice sites, as well as inhomogeneity in the replacement of zirconium ions by lithium ions.
A decrease in the crystal lattice parameters, as is known, leads to a decrease in its volume and, consequently, to a decrease in porosity and an increase in the density of ceramics. Figure 4 shows the results of changes in the density and porosity of the ceramics depending on the X component concentration. A change in density, including its decrease at high annealing temperatures of 1500 °C, is due to the fact that with a change in the components used for synthesis, by varying them with a subsequent increase in LiClO4·3H2O, the crystal lattice volume decreases, which leads to ceramic compaction. At the same time, the difference from the density values presented in [28], which are close to the theoretical values, is that, at high lithium concentrations, there is an overall increase in the lattice volume, which leads to lower ceramic density values.
As can be seen from the data presented, a change in the crystal lattice parameters leads to the compaction of ceramics, as well as the approximation of the experimentally obtained density values to the theoretical value (95–97%). In this case, porosity decreases from 4.1% to 2.6%, with an increase in the X component, which, in turn, results in the ceramics strengthening to mechanical stress.
Figure 5 shows the measurement results of the ceramics’ single compression resistance. The change in the resistance value depending on the concentration of X varies in the range from 29.3 to 38.4 N, while for concentrations X = 0.4–0.5, an increase in resistance of 25–30% is observed. Such an increase in single compression resistance is due to an increase in the density of the ceramics, as well as a change in the dislocation density, which leads to a strengthening effect and an increase in fracture resistance. A comparative analysis with the known literature data on measurements of resistance to single compression, taken from [20,35,36], indicated that the synthesized ceramics have an increased resistance to mechanical stress, as well as greater strength. At the same time, as shown in [30], in which the properties of two-component Li4SiO4-Li2ZrO3 ceramics were studied, an increase in density led to an increase in strength, which confirms the obtained results. The authors found that an increase in the resistance of ceramics to mechanical stress was not only due to an increase in density but also due to an increase in the content of Li2ZrO3 in the composition of the ceramics. A similar effect was also observed in [36], where it was shown that a change in component content in the composition of ceramics leads to an increase in resistance to mechanical stress.
The results of the ceramic hardness obtained by indentation are shown in Figure 6.
As can be seen from the presented data on changes in the hardness value of the surface layer of ceramics, an increase in dislocation density leads to an increase in resistance to mechanical stress. At the same time, in the case of component concentrations of X = 0.4–0.5, the ratio of dislocation density to hardening is 3:1. The hardening effect is due to the creation of additional obstacles to the propagation of microcracks due to the high density of dislocations, which leads to an increase in resistance to mechanical stress. Moreover, an important role in strengthening is played by a decrease in the porosity of the ceramics and an increase in density; this causes a decrease in the concentration of disordered structural inclusions, which, in turn, leads to the strengthening of ceramics.
The important characteristics for the determination of the operational parameters of lithium-containing ceramics are their thermophysical parameters, which play an important role in the processes of heat transfer and heat removal. Figure 7 shows the results of the change in the thermal conductivity coefficient depending on the concentration of the X component.
As can be seen from the data presented in Figure 7a, the value of the thermal conductivity coefficient in a wide measured temperature range remains almost unchanged, with a slight increase in thermal conductivity (no more than 0.5%) at elevated measurement temperatures. At the same time, the dependences obtained indicate a high stability of thermal conductivity over the entire temperature range. A comparative diagram of the average value of thermal conductivity shows that a change in the X component concentration leads to an increase in thermal conductivity of 3.5–7%, which indicates an increase in thermal conductivity due to structural changes, as well as a decrease in porosity. For example, as a comparison, Figure 7b shows the results of the thermal conductivity for Li2ZrO3 used as a blanket material [37]. According to this work, the change in thermal conductivity is influenced by two factors that are associated with heat transfer and heat transfer processes, as well as the contact area. In our case, the contact area was the same for all the samples under study; thus, the main changes are associated with the processes of heat transfer and heat transfer, which directly depend on the structure of the ceramics, as well as porosity. A decrease in porosity as a result of a change in the X component concentration leads to an increase in heat transfer and, accordingly, in the thermal conductivity. It should be noted that such a significant difference from the results in [32] is due to the fact that the studied ceramics in this work were highly porous samples with a packing density of 1.921 (at a density of 3.1 g/cm3, 53.4% of the theoretical value).

4. Conclusions

In conclusion, the results of the research can be summarized as follows:
  • The proposed conditions to obtain Li2ZrO3 ceramics with different contents of the initial components xLiClO4·3H2O and (1−x)ZrO2 (x = 0.1–0.5) at an annealing temperature of 1500 °C make it possible to obtain highly ordered pure ceramics with a monoclinic phase (Li2ZrO3) and a density close to the theoretical value (95–97%).
  • The decrease in the crystal lattice parameters for the Li2ZrO3 monoclinic phase is due to the substitution of zirconium ions (atomic radius = 13.9 Å) by lithium ions (atomic radius = 7.1 Å), and it indicates an increase in lithium concentration in the ceramic structure. At the same time, changes in the crystal lattice parameters depending on the X component concentration are anisotropic.
  • A change in the X component content leads to an increase in the dislocation density, a change in which leads to the strengthening of ceramics and an increase in resistance to mechanical stress and cracking.
  • An increase in the density of ceramics, as well as a decrease in density, leads to an increase in the thermal conductivity coefficient of 3.5–7%.

Author Contributions

Conceptualization, M.V.Z., B.A. and A.L.K.; methodology, B.A., D.I.S. and A.L.K.; formal analysis, D.I.S. and M.V.Z.; investigation, B.A., A.L.K. and M.V.Z.; resources, M.V.Z.; writing—original draft preparation, review, and editing, B.A., M.V.Z. and A.L.K.; visualization, M.V.Z.; supervision, M.V.Z. All authors have read and agreed to the published version of the manuscript.

Funding

This research was funded by the Science Committee of the Ministry of Education and Science of the Republic of Kazakhstan (No. BR11765580).

Institutional Review Board Statement

Not applicable.

Informed Consent Statement

Not applicable.

Data Availability Statement

Not applicable.

Conflicts of Interest

The authors declare that they have no conflict of interest.

References

  1. Jiang, S.; Tu, J.; Yang, X.; Gui, N. A review of pebble flow study for pebble bed high temperature gas-cooled reactor. Exp. Comput. Multiph. Flow 2019, 1, 159–176. [Google Scholar] [CrossRef] [Green Version]
  2. Piazza, G.; Reimann, J.; Knitter, E.; Roux, N.; Lulewicz, J.D. Characterisation of ceramic breeder materials for the helium cooled pebble bed blanket. J. Nucl. Mater. 2002, 307, 811–816. [Google Scholar] [CrossRef]
  3. Moscato, I.; Barucca, L.; Ciattaglia, S.; D’Aleo, F.; Di Maio, P.A.; Federici, G.; Tarallo, A. Progress in the design development of EU DEMO helium-cooled pebble bed primary heat transfer system. Fusion Eng. Des. 2019, 146, 2416–2420. [Google Scholar] [CrossRef]
  4. Zhang, G.; Chen, J.; Tang, G.; Gledenov, Y.M.; Sedysheva, M.; Khuukhenkhuu, G. Measurement of differential and angle-integrated cross sections of the 6Li (n, t) 4He reaction in the MeV neutron energy range. Nucl. Instrum. Methods Phys. Res. Sect. A Accel. Spectrometers Detect. Assoc. Equip. 2006, 566, 615–621. [Google Scholar] [CrossRef]
  5. Biersack, J.P.; Fink, D. Observation of the blocking effect after 6Li (n, t) 4He reactions with thermal neutrons. Nucl. Instrum. Methods 1973, 108, 397–399. [Google Scholar] [CrossRef]
  6. Dang, C.; Yang, M.; Gong, Y.; Feng, L.; Wang, H.; Shi, Y.; Shi, Q.; Qi, J.; Lu, T. A promising tritium breeding material: Nanostructured 2Li2TiO3-Li4SiO4 biphasic ceramic pebbles. J. Nucl. Mater. 2018, 500, 265–269. [Google Scholar] [CrossRef]
  7. Hong, M.; Zhang, Y.; Mi, Y.; Xiang, M.; Zhang, Y. Fabrication and characterization of Li2TiO3 core–shell pebbles with enhanced lithium density. J. Nucl. Mater. 2014, 445, 111–116. [Google Scholar] [CrossRef]
  8. Chen, R.; Yang, M.; Shi, Y.; Wang, H.; Guo, H.; Zeng, Y.; Qi, J.; Shi, Q.; Liao, Z.; Lu, T. Development of an advanced core-shell ceramic pebble with Li4TiO4 pure phase core and Li2TiO3 nanostructured shell by a physical coating method. J. Nucl. Mater. 2019, 520, 252–257. [Google Scholar] [CrossRef]
  9. Xiao, C.; Gao, X.; Kobayashi, M.; Kawasaki, K.; Uchimura, H.; Toda, K.; Kang, C.; Chen, X.; Wang, H.; Peng, S.; et al. Tritium release kinetics in lithium orthosilicate ceramic pebbles irradiated with low thermal-neutron fluence. J. Nucl. Mater. 2013, 438, 46–50. [Google Scholar] [CrossRef]
  10. Leys, J.M.; Zarins, A.; Cipa, J.; Baumane, L.; Kizane, G.; Knitter, R. Radiation-induced effects in neutron-and electron-irradiated lithium silicate ceramic breeder pebbles. J. Nucl. Mater. 2020, 540, 152347. [Google Scholar] [CrossRef]
  11. Shlimas, D.I.; Zdorovets, M.V.; Kozlovskiy, A.L. Synthesis and resistance to helium swelling of Li2TiO3 ceramics. J. Mater. Sci. Mater. Electron. 2020, 3, 12903–12912. [Google Scholar] [CrossRef]
  12. Blynskiy, P.; Chikhray, Y.; Kulsartov, T.; Gabdullin, M.; Zaurbekova, Z.; Kizane, G.; Kenzhin, Y.; Tolenova, A.; Nesterov, E.; Shaimerdenov, A. Experiments on tritium generation and yield from lithium ceramics during neutron irradiation. Int. J. Hydrogen Energy 2021, 46, 9186–9192. [Google Scholar] [CrossRef]
  13. Kulsartov, T.; Tazhibayeva, I.; Gordienko, Y.; Chikhray, E.; Tsuchiya, K.; Kawamura, H.; Kulsartova, A. Study of tritium and helium release from irradiated lithium ceramics Li2TiO3. Fusion Sci. Technol. 2011, 60, 1139–1142. [Google Scholar] [CrossRef]
  14. Ba, J.; Zeng, R.; Yan, X.; Li, R.; Wu, W.; Li, F.; Xiang, X.; Meng, D.; Tang, T. Long-term helium bubble evolution in sequential He+ and H+ irradiated Li4SiO4. Ceram. Int. 2021, 47, 32310–32317. [Google Scholar] [CrossRef]
  15. Zhao, M.; Memon, M.Z.; Ji, G.; Yang, X.; Vuppaladadiyama, A.K.; Song, Y. Alkali metal bifunctional catalyst sorbents enabled biomass pyrolysis for enhanced hydrogen production. In this study, Li2ZrO3, Li4SiO4, and Na2ZrO3 were selected as catalystsorbent bifunctional materials to enhance the pyrolysis of sawdust. TIDEE TERI Inf. Dig. Energy Environ. 2021, 20, 52. [Google Scholar]
  16. Roux, N.; Abassin, J.J.; Briec, M.; Cruz, D.; Flament, T.; Schuster, I. Compatibility behavior of beryllium with LiAlO2 and Li2ZrO3 ceramics, with 316 L and 1.4914 steels in SIBELIUS. J. Nucl. Mater. 1992, 191, 168–172. [Google Scholar] [CrossRef]
  17. Ma, J.; Fu, Z.; Liu, P.; Tang, X. Microwave dielectric properties of low-fired Li2ZrO3–ZnO composite ceramics. J. Mater. Sci. Mater. Electron. 2016, 27, 232–236. [Google Scholar] [CrossRef]
  18. Avila, R.E.; Peña, L.A.; Jiménez, J.C. Surface desorption and bulk diffusion models of tritium release from Li2TiO3 and Li2ZrO3 pebbles. J. Nucl. Mater. 2010, 405, 244–251. [Google Scholar] [CrossRef]
  19. Rasneur, B.; Thevenot, G.; Bouilloux, Y. Irradiation behavior of LiAlO2 and Li2ZrO3 ceramics in the ALICE 3 experiment. J. Nucl. Mater. 1992, 191–194, 243–247. [Google Scholar] [CrossRef]
  20. Hoshino, T. Pebble fabrication of super advanced tritium breeders using a solid solution of Li2+xTiO3+y with Li2ZrO3. Nucl. Mater. Energy 2016, 9, 221–226. [Google Scholar] [CrossRef] [Green Version]
  21. Yasnó, J.P.; Conconi, S.; Visintin, A.; Suárez, G. Non-isothermal reaction mechanism and kinetic analysis for the synthesis of monoclinic lithium zirconate (m-Li2ZrO3) during solid-state reaction. J. Anal. Sci. Technol. 2021, 12, 15. [Google Scholar] [CrossRef]
  22. Yang, M.; Gong, Y.; Ran, G.; Wang, H.; Chen, R.; Huang, Z.; Shi, Q.; Chen, X.; Lu, T.; Xiao, C. Tritium release behavior of Li4SiO4 and Li4SiO4+ 5 mol% TiO2 ceramic pebbles with small grain size. J. Nucl. Mater. 2019, 514, 284–289. [Google Scholar] [CrossRef]
  23. Yang, M.; Ran, G.; Wang, H.; Dang, C.; Huang, Z.; Chen, X.; Lu, T.; Xiao, C. Fabrication and tritium release property of Li2TiO3-Li4SiO4 biphasic ceramics. J. Nucl. Mater. 2018, 503, 151–156. [Google Scholar] [CrossRef]
  24. Kulsartov, T.; Zaurbekova, Z.; Knitter, R.; Shaimerdenov, A.; Chikhray, Y.; Askerbekov, S.; Akhanov, A.; Kenzhina, I.; Kizane, G.; Kenzhin, Y.; et al. Studies of two-phase lithium ceramics Li4SiO4-Li2TiO3 under conditions of neutron irradiation. Nucl. Mater. Energy 2022, 30, 101129. [Google Scholar] [CrossRef]
  25. Qi, Q.; Wang, J.; Zhou, Q.; Zhang, Y.; Zhao, M.; Gu, S.; Nakata, M.; Zhou, H.; Oya, Y.; Luo, G.-N. Comparison of tritium release behavior in Li2TiO3 and promising core-shell Li2TiO3–Li4SiO4 biphasic ceramic pebbles. J. Nucl. Mater. 2020, 539, 152330. [Google Scholar] [CrossRef]
  26. Yang, M.; Zhao, L.; Ran, G.; Gong, Y.; Wang, H.; Peng, S.; Xiao, C.; Lu, T. Tritium release behavior of Li2TiO3 and 2Li2TiO3-Li4SiO4 biphasic ceramic pebbles fabricated by microwave sintering. Fusion Eng. Des. 2021, 168, 112390. [Google Scholar] [CrossRef]
  27. Zhou, Q.; Togari, A.; Nakata, M.; Zhao, M.; Sun, F.; Xu, Q.; Oya, Y. Release kinetics of tritium generation in neutron irradiated biphasic Li2TiO3–Li4SiO4 ceramic breeder. J. Nucl. Mater. 2019, 522, 286–293. [Google Scholar] [CrossRef]
  28. Zdorovets, M.V.; Kozlovskiy, A.L.; Abyshev, B.; Yansepbayev, T.A.; Uzbekgaliyev, R.U.; Shlimas, D.I. Study of Phase Formation Processes in Li2ZrO3 Ceramics Obtained by Mechanochemical Synthesis. Crystals 2022, 12, 21. [Google Scholar] [CrossRef]
  29. Kuzovkov, V.N.; Popov, A.I.; Kotomin, E.A.; Monge, M.A.; Gonzales, R.; Chen, Y. Kinetics of nanocavity formation based on F-center aggregation in thermochemically reduced MgO single crystals. Phys. Rev. B 2001, 64, 064102. [Google Scholar] [CrossRef] [Green Version]
  30. Lushchik, A.; Feldbach, E.; Kotomin, E.A.; Kudryvtseva, I.; Kuzovkov, V.N.; Popov, A.I.; Seeman, V.; Shablonin, E. Distinctive features of diffusion-controlled radiation defect recombination in stoichiometric magnesium aluminate spinel single crystals and transparent polycrystalline ceramics. Sci. Rep. 2020, 10, 7810. [Google Scholar] [CrossRef]
  31. Kotomin, E.A.; Kuzovkov, V.N.; Popov, A.I. The kinetics of defect aggregation and metal colloid formation in ionic solids under irradiation. Radiat. Eff. Defects Solids 2001, 155, 113–125. [Google Scholar] [CrossRef]
  32. Klym, H.; Karbovnyk, I.; Piskunov, S.; Popov, A.I. Positron Annihilation Lifetime Spectroscopy Insight on Free Volume Conversion of Nanostructured MgAl2O4 Ceramics. Nanomaterials 2021, 11, 3373. [Google Scholar] [CrossRef] [PubMed]
  33. Klym, H.; Ingram, A.; Shpotyuk, O.; Hadzaman, I.; Solntsev, V.; Hotra, O.; Popov, A.I. Positron annihilation characterization of free volume in micro-and macro-modified Cu0.4Co0.4Ni0.4Mn1.8O4 ceramics. Low Temp. Phys. 2016, 42, 601–605. [Google Scholar] [CrossRef] [Green Version]
  34. Heiba, Z.; El-Sayed, K. Structural and anisotropic thermal expansion correlation of Li2ZrO3 at different temperatures. J. Appl. Crystallogr. 2002, 35, 634–636. [Google Scholar] [CrossRef] [Green Version]
  35. Rao, J.G.; Mazumder, R.; Bhattacharyya, S.; Chaudhuri, P. Fabrication of Li4SiO4-Li2ZrO3 composite pebbles using extrusion and spherodization technique with improved crush load and moisture stability. J. Nucl. Mater. 2018, 514, 321–333. [Google Scholar]
  36. Leys, O.; Kolb, M.H.H.; Pucci, A.; Knitter, R. Study of lithium germanate additions to advanced ceramic breeder pebbles. J. Nucl. Mater. 2019, 518, 234–240. [Google Scholar] [CrossRef]
  37. Enoeda, M.; Ohara, Y.; Roux, N.; Ying, A.; Pizza, G.; Malang, S. Effective Thermal Conductivity Measurement of the Candidate Ceramic Breeder Pebble Beds by the Hot Wire Method. Fusion Technol. 2001, 39, 612–616. [Google Scholar] [CrossRef]
Technologies 10 00058 g001 550
Figure 1. Schematic representation of the production of Li2+4xZr4−xO3 ceramics.
Figure 1. Schematic representation of the production of Li2+4xZr4−xO3 ceramics.
Technologies 10 00058 g001
Technologies 10 00058 g002 550
Figure 2. X-ray diffraction patterns of the studied ceramics.
Figure 2. X-ray diffraction patterns of the studied ceramics.
Technologies 10 00058 g002
Technologies 10 00058 g003a 550Technologies 10 00058 g003b 550
Figure 3. (a) Results of crystal lattice deformation; (b) results of beta angle deformation; (c) results of crystal lattice volume deformation.
Figure 3. (a) Results of crystal lattice deformation; (b) results of beta angle deformation; (c) results of crystal lattice volume deformation.
Technologies 10 00058 g003aTechnologies 10 00058 g003b
Technologies 10 00058 g004 550
Figure 4. Ceramic density and porosity change results.
Figure 4. Ceramic density and porosity change results.
Technologies 10 00058 g004
Technologies 10 00058 g005 550
Figure 5. Results of strength measurements for single compression resistance.
Figure 5. Results of strength measurements for single compression resistance.
Technologies 10 00058 g005
Technologies 10 00058 g006 550
Figure 6. Ceramic hardening results depending on the concentration of component X.
Figure 6. Ceramic hardening results depending on the concentration of component X.
Technologies 10 00058 g006
Technologies 10 00058 g007 550
Figure 7. (a) Dependences of the change in the thermal conductivity coefficient on temperature; (b) results of the change in the average value of the thermal conductivity coefficient.
Figure 7. (a) Dependences of the change in the thermal conductivity coefficient on temperature; (b) results of the change in the average value of the thermal conductivity coefficient.
Technologies 10 00058 g007
Table
Table 1. Unit-cell parameters and crystallinity characteristics for Li2ZrO3 ceramics.
Table 1. Unit-cell parameters and crystallinity characteristics for Li2ZrO3 ceramics.
ParameterContent of LiClO4·3H2O Component
0.10.20.30.40.5
Li2ZrO3 monoclinic phase (PDF-01-070-8744)
(a0 = 5.42660 Å, b0 = 9.03100 Å, c0 = 5.42270 Å, β0 = 112.720°, V0 = 245.13 Å3)
Crystal lattice parameters, Å		a = 5.3915 ± 0.0011, b = 9.0363 ± 0.0014, c = 5.4216 ± 0.0021,
β = 112.609°		a = 5.3829 ± 0.0017, b = 9.0291 ± 0.0022, c = 5.4173 ± 0.0024,
β = 112.564°		a = 5.3786 ± 0.0018, b = 9.0061 ± 0.0015, c = 5.4056 ± 0.0022,
β = 112.474°		a = 5.3691 ± 0.0016, b = 8.9989 ± 0.0013, c = 5.3855 ± 0.0014,
β = 112.384°		a = 5.3617 ± 0.0015, b = 8.9901 ± 0.0023, c = 5.3761 ± 0.0017,
β = 112.010°
Crystal volume, Å3243.84 ± 0.19243.14 ± 0.16241.96 ± 0.12240.61 ± 0.15240.25 ± 0.14
Crystallinity degree, % (structural ordering value)90.2 ± 0.489.3 ± 0.588.7 ± 0.388.6 ± 0.588.0 ± 0.7
Crystallite size, nm (size determined using the Scherer equation)80.2 ± 2.576.4 ± 2.676.3 ± 2.872.2 ± 2.465.5 ± 2.1
Dislocation density, 1010 1/cm20.1550.1710.1720.1910.233
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Share and Cite

MDPI and ACS Style

Kozlovskiy, A.L.; Abyshev, B.; Shlimas, D.I.; Zdorovets, M.V. Study of Structural, Strength, and Thermophysical Properties of Li2+4xZr4−xO3 Ceramics. Technologies 2022, 10, 58. https://0-doi-org.brum.beds.ac.uk/10.3390/technologies10030058

AMA Style

Kozlovskiy AL, Abyshev B, Shlimas DI, Zdorovets MV. Study of Structural, Strength, and Thermophysical Properties of Li2+4xZr4−xO3 Ceramics. Technologies. 2022; 10(3):58. https://0-doi-org.brum.beds.ac.uk/10.3390/technologies10030058

Chicago/Turabian Style

Kozlovskiy, Artem L., Bauyrzhan Abyshev, Dmitriy I. Shlimas, and Maxim V. Zdorovets. 2022. "Study of Structural, Strength, and Thermophysical Properties of Li2+4xZr4−xO3 Ceramics" Technologies 10, no. 3: 58. https://0-doi-org.brum.beds.ac.uk/10.3390/technologies10030058

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop