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Ceramics, Volume 7, Issue 4 (December 2024) – 27 articles

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23 pages, 5362 KiB  
Review
Superior Ceramics: Graphene and Carbon Nanotube (CNT) Reinforcements
by Katalin Balázsi, Alaa Almansoori and Csaba Balázsi
Ceramics 2024, 7(4), 1758-1778; https://doi.org/10.3390/ceramics7040112 (registering DOI) - 20 Nov 2024
Viewed by 153
Abstract
Carbon nanotube (CNT)/graphene ceramic composites with outstanding properties are expected to replace a number of components currently used in the automotive and aerospace industries in the future. Consequently, this area of research has progressed significantly. This review paper, therefore, delves into the enhancement [...] Read more.
Carbon nanotube (CNT)/graphene ceramic composites with outstanding properties are expected to replace a number of components currently used in the automotive and aerospace industries in the future. Consequently, this area of research has progressed significantly. This review paper, therefore, delves into the enhancement of ceramic properties through the integration of graphene and CNTs. These reinforcements are known to mitigate the inherent brittleness of ceramics, thereby unlocking their potential for applications in sectors requiring high mechanical reliability, such as the aerospace, automotive, and biomedical industries. By summarizing recent research, this paper outlines various preparation methods, including ball milling, heat pressing and spark plasma sintering, and discusses how these techniques contribute to improved mechanical and thermal performance. This review emphasizes the critical role of graphene and CNT ratios, sizes, and their synergistic effects in enhancing fracture toughness, machinability, and overall structural integrity. Thus, this paper provides a comprehensive overview of the current research in this area and discusses the potential of these technologies. Full article
(This article belongs to the Special Issue Advances in Ceramics, 2nd Edition)
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16 pages, 5518 KiB  
Article
Comparing the Efficacies of Electrospun ZnO and TiO2 Nanofibrous Interlayers for Electron Transport in Perovskite Solar Cells
by Abdullah Zafar, Waqar Iqbal, Shahzaib Khan, Aiyeshah Alhodaib and Mahvish Fatima
Ceramics 2024, 7(4), 1742-1757; https://doi.org/10.3390/ceramics7040111 - 13 Nov 2024
Viewed by 379
Abstract
ZnO and TiO2 are both well-known electron transport materials. Their comparison of performance is considered advantageous and novel. Therefore, a viable electrospinning route was considered for the development of highly polycrystalline TiO2 and ZnO nanofibers as an electron transport material (ETM) [...] Read more.
ZnO and TiO2 are both well-known electron transport materials. Their comparison of performance is considered advantageous and novel. Therefore, a viable electrospinning route was considered for the development of highly polycrystalline TiO2 and ZnO nanofibers as an electron transport material (ETM) for perovskite solar cells. The materials were well-characterized in terms of different analytical techniques. The X-ray diffraction detected polycrystalline structural properties corresponding to TiO2 and ZnO. Morphological analysis by scanning electron microscopy revealed that the nanofibers are long, uniform, and polycrystalline, having a diameter in the nanometer range. Optoelectronic properties showed that TiO2 and ZnO exhibit absorption values in the ultraviolet and visible ranges, and band gap values for TiO2 and ZnO were 3.3 and 3.2 eV, respectively. TiO2 bandgap and semiconductor nature were more compatible with Electron Transport Layer (ETL) compared to ZnO. Electrical studies revealed that TiO2 nanofibers have enhanced values of conductivity and sheet carrier mobility compared to ZnO nanofibers. Therefore, higher photovoltaic conversion efficiency was achieved for TiO2 nanofibers (10.4%) compared to ZnO (8.5%). Full article
(This article belongs to the Special Issue Advances in Electronic Ceramics)
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15 pages, 7626 KiB  
Article
A DFT Study on the Structural, Electronic, Optical, and Elastic Properties of BLSFs XTi4Bi4O15 (X = Sr, Ba, Be, Mg) for Solar Energy Applications
by Ahmad Hussain, Fatima Kainat, Ameer Hamza, Adeela Naz, Nawishta Jabeen, Tuba Munawar and Muhammad Adnan Qaiser
Ceramics 2024, 7(4), 1727-1741; https://doi.org/10.3390/ceramics7040110 - 11 Nov 2024
Viewed by 330
Abstract
For the first time, a theoretical investigation has been conducted into the structural, electrical, elastic, and optical properties of innovative bismuth-layered structure ferroelectric (BLSF) materials XTi4Bi4O15 (where X = Sr, Ba, Be, and Mg). For all of the [...] Read more.
For the first time, a theoretical investigation has been conducted into the structural, electrical, elastic, and optical properties of innovative bismuth-layered structure ferroelectric (BLSF) materials XTi4Bi4O15 (where X = Sr, Ba, Be, and Mg). For all of the calculations, PBE-GGA and the ultra-soft pseudopotential plane wave techniques have been implemented with the DFT-based CASTEP simulation tool. Based on the exchange correlation approximation, the calculations reveal that XTi4Bi4O15 (X = Sr, Ba, Be, and Mg) materials demonstrate direct band-gap semiconductor behavior with an estimated density functional fundamental gap in the range from 1.966 eV to 2.532 eV. The optical properties of these materials exhibit strong absorption and low reflection in the visible range. Moreover, the estimations of the elastic properties of the materials have shown mechanical stability and ductile behavior (due to B/G > 1.75), where G and B denote the shear modulus and the bulk modulus. Based on the above-mentioned highlights, it can be confidently stated that these materials are promising potential candidates for photovoltaic applications and solar cells due to their suitable direct band gap and high absorption coefficient. Full article
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16 pages, 3887 KiB  
Article
Evolution of CO2 Uptake Degree of Ordinary Portland Cement During Accelerated Aqueous Mineralisation
by Giuseppe Ferrara, Pedro Humbert, Davide Garufi and Paola Palmero
Ceramics 2024, 7(4), 1711-1726; https://doi.org/10.3390/ceramics7040109 - 11 Nov 2024
Viewed by 301
Abstract
The utilisation of carbonation treatments to produce building materials is emerging as a valuable strategy to reduce CO2 emissions in the construction sector. It is of great importance to regulate the degree of carbonation when the mineralisation process is combined with hydration, [...] Read more.
The utilisation of carbonation treatments to produce building materials is emerging as a valuable strategy to reduce CO2 emissions in the construction sector. It is of great importance to regulate the degree of carbonation when the mineralisation process is combined with hydration, as a high CO2 uptake may impede the development of adequate strength. A significant number of studies focus on attaining the maximum carbonation degree, with minimal attention paid to the examination of the evolution of CO2 uptake over the initial stages of the process. In this context, the present study aims to investigate the evolution of CO2 uptake over time during carbonation. Ordinary Portland Cement (OPC) is employed as material, with aqueous carbonation selected as the mineralisation process. This investigation encompasses a range of carbonation durations, spanning from 5 to 40 min. The analysis of the evolution of the mineral composition with time demonstrated that the rate of the carbonation reaction accelerates in the initial minutes, resulting in the conversion of all the portlandite produced during the hydration process in the initial 10 min. Quantitative analysis of the carbonation degree indicated that the CO2 uptake at 40 min is equal to 19.1%, which is estimated to be approximately 70% of the maximum achievable value. By contributing to the understanding of the early carbonation mechanisms in aqueous conditions of OPC, this study provides valuable support for further investigation focused on the use of cement mineralisation processes to produce building materials. Full article
(This article belongs to the Special Issue Ceramics in the Circular Economy for a Sustainable World)
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16 pages, 3132 KiB  
Article
Effect of High Heat Flux of Helium and Hydrogen Plasma Jet on the Material Properties of Piezoelectric PZT-Ceramics
by Galina Yu. Sotnikova, Alexander V. Ankudinov, Alexander V. Voronin, Gennady A. Gavrilov, Alexey L. Glazov, Valery Yu. Goryainov, Nina V. Zaitseva, Alexey V. Nashchekin, Rostislav S. Passet, Alexander A. Vorob’ev and Andrey V. Sotnikov
Ceramics 2024, 7(4), 1695-1710; https://doi.org/10.3390/ceramics7040108 - 9 Nov 2024
Viewed by 447
Abstract
A set of experimental and measurement techniques to study the influence of a plasma jet on the main material parameters of piezoelectric ceramics has been presented. A series of plasma experiments has been carried out using a pulsed plasma jet system. It allows [...] Read more.
A set of experimental and measurement techniques to study the influence of a plasma jet on the main material parameters of piezoelectric ceramics has been presented. A series of plasma experiments has been carried out using a pulsed plasma jet system. It allows of a metered-dose exposure to plasma of different composition and fluence with a constant particle flux density of 1021/m2, energy flux density of 0.1 MJ/m2 and average particle energy of 100–200 eV in a pulse duration of 15 μs. The study of the effects that a repeated exposure to an extreme heat flux of helium and hydrogen plasmas has on the near-surface layer structure and basic material parameters of mass-produced piezoelectric ceramic samples has been presented. The main result of the research is an experimental confirmation of the surface micro-structuring starting after just a few cycles of plasma exposure while only a slight decrease of the main material parameters as well as the preservation of polarization has been observed for two types of different compositions of PZT-ceramics. A further increase in the number of exposure pulses leads to practically no change of main material parameters of both ceramics, even showing a tendency for recovery instead. Full article
(This article belongs to the Special Issue Advances in Ceramics, 2nd Edition)
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25 pages, 6320 KiB  
Article
Tunable Optical Properties and Relaxor Behavior in Ni/Ba Co-Doped NaNbO3 Ceramics: Pathways Toward Multifunctional Applications
by Tawfik Chaabeni, Zohra Benzarti, Najmeddine Abdelmoula and Slim Zghal
Ceramics 2024, 7(4), 1670-1694; https://doi.org/10.3390/ceramics7040107 - 8 Nov 2024
Viewed by 519
Abstract
In this study, Ni/Ba co-doped NaNbO3 ceramics (NBNNOx) were synthesized using a solid-state method to explore the effects of Ni2+ and Ba2+ ion substitution on the structural, optical, and dielectric properties of NaNbO3. X-ray diffraction (XRD) [...] Read more.
In this study, Ni/Ba co-doped NaNbO3 ceramics (NBNNOx) were synthesized using a solid-state method to explore the effects of Ni2+ and Ba2+ ion substitution on the structural, optical, and dielectric properties of NaNbO3. X-ray diffraction (XRD) confirmed that the ceramics retained an orthorhombic structure, with crystallinity improving as the doping content (x) increased. Significant lattice distortions induced by the Ni/Ba co-doping were observed, which were essential for preserving the perovskite structure. Raman spectroscopy revealed local structural distortions, influencing optical properties and promoting relaxor behavior. Diffuse reflectance measurements revealed a significant decrease in band gap energy from 3.34 eV for undoped NaNbO3 to 1.08 eV at x = 0.15, highlighting the impact of co-doping on band gap tunability. Dielectric measurements indicated relaxor-like behavior at room temperature for x = 0.15, characterized by frequency-dependent anomalies in permittivity and dielectric loss, likely due to ionic disorder and structural distortions. These findings demonstrate the potential of Ni/Ba co-doped NaNbO3 ceramics for lead-free perovskite solar cells and other functional devices, where tunable optical and dielectric properties are highly desirable. Full article
(This article belongs to the Special Issue Advances in Electronic Ceramics)
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12 pages, 4650 KiB  
Article
Scratch-Induced Wear Behavior of Multi-Component Ultra-High-Temperature Ceramics
by Gia Garino, Ambreen Nisar, Abhijith K. Sukumaran and Arvind Agarwal
Ceramics 2024, 7(4), 1658-1669; https://doi.org/10.3390/ceramics7040106 - 8 Nov 2024
Viewed by 444
Abstract
Multi-component ultra-high-temperature ceramics (MC-UHTCs) are promising for high-temperature applications due to exceptional thermo-mechanical properties, yet their wear characteristics remain unexplored. Herein, the wear behavior of binary (Ta, Nb)C, ternary (Ta, Nb, Hf)C, and quaternary (Ta, Nb, Hf, Ti)C UHTCs synthesized via spark plasma [...] Read more.
Multi-component ultra-high-temperature ceramics (MC-UHTCs) are promising for high-temperature applications due to exceptional thermo-mechanical properties, yet their wear characteristics remain unexplored. Herein, the wear behavior of binary (Ta, Nb)C, ternary (Ta, Nb, Hf)C, and quaternary (Ta, Nb, Hf, Ti)C UHTCs synthesized via spark plasma sintering (SPS) is investigated. Gradual addition of equimolar UHTC components improves the wear resistance of MC-UHTCs, respectively, by ~29% in ternary UHTCs and ~49% in quaternary UHTCs when compared to binary UHTCs. Similarly, the penetration depth decreased from 115.14 mm in binary UHTCs to 73.48 mm in ternary UHTCs and 44.41 mm in quaternary UHTCs. This has been attributed to the complete solid solutioning, near-full densification and higher hardness (~up to 30%) in quaternary UHTCs. Analysis of the worn-out surface suggests pull-out, radial, and edge micro-cracking and delamination as the dominant wear mechanisms in binary and ternary UHTCs. However, grain deformation and minor delamination are the dominant wear mechanisms in quaternary UHTCs. This study underscores the potential of MC-UHTCs for tribological applications where material experiences removal and inelastic deformation under high mechanical loading. Full article
(This article belongs to the Special Issue Mechanical Behavior and Reliability of Engineering Ceramics)
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19 pages, 5246 KiB  
Article
Prediction of Physical and Mechanical Properties of Al2O3–TiB2–TiC Composites Using Design of Mixture Experiments
by Nestor Washington Solís Pinargote, Yuri Pristinskiy, Yaroslav Meleshkin, Alexandra Yu. Kurmysheva, Aleksandr Mozhaev, Nikolay Lavreshin and Anton Smirnov
Ceramics 2024, 7(4), 1639-1657; https://doi.org/10.3390/ceramics7040105 - 7 Nov 2024
Viewed by 484
Abstract
In this study, the design of mixture experiments was used to find empirical models that could predict, for a first approximation, the relative density, flexural strength, Vickers hardness and fracture toughness of sintered composites in order to identify further areas of research in [...] Read more.
In this study, the design of mixture experiments was used to find empirical models that could predict, for a first approximation, the relative density, flexural strength, Vickers hardness and fracture toughness of sintered composites in order to identify further areas of research in the Al2O3-TiB2-TiC ternary system. The composites were obtained by spark plasma sintering (SPS) of these mixtures at 1700 °C, 80 MPa and a dwell of 3 min. The obtained experimental results were analyzed in the statistical analysis software Minitab 17, and then, different regression models were obtained for each property. Based on the selected models, contour plots were made in the Al2O3–TiB2–TiC simplex for a visual representation of the predicted results. By combining these plots, it was possible to obtain one common zone in the Al2O3–TiB2–TiC simplex, which shows the following combination of physical and mechanical properties for sintered samples: relative densities, flexural strength, Vickers hardness, and fracture toughness of than 99%, 500 MPa, 18 GPa, and 7.0 МPa·m1/2, respectively. For a first approximation in determining the further area of research, the obtained models describe well the behavior of the studied properties. The results of the analysis showed that the design of mixture experiments allows us to identify the most promising compositions in terms of mechanical properties without resorting to labor-intensive and financially expensive full-scale experiments. Our work shows that 10 different compositions were required for preliminary analysis. Full article
(This article belongs to the Special Issue Advances in Ceramics, 2nd Edition)
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23 pages, 1939 KiB  
Review
Comprehensive Study of Stereolithography and Digital Light Processing Printing of Zirconia Photosensitive Suspensions
by Patrik Sokola, Petr Ptáček, Arijeta Bafti, Ivana Panžić, Vilko Mandić, Jan Blahut and Michal Kalina
Ceramics 2024, 7(4), 1616-1638; https://doi.org/10.3390/ceramics7040104 - 4 Nov 2024
Viewed by 554
Abstract
Zirconia ceramics are used in a wide range of applications, including dental restorations, bioimplants, and fuel cells, due to their accessibility, biocompatibility, chemical resistance, and favorable mechanical properties. Following the development of 3D printing technologies, it is possible to rapidly print zirconia-based objects [...] Read more.
Zirconia ceramics are used in a wide range of applications, including dental restorations, bioimplants, and fuel cells, due to their accessibility, biocompatibility, chemical resistance, and favorable mechanical properties. Following the development of 3D printing technologies, it is possible to rapidly print zirconia-based objects with high precision using stereolithography (SLA) and digital light processing (DLP) techniques. The advantages of these techniques include the ability to print multiple objects simultaneously on the printing platform. To align with the quality standards, it is necessary to focus on optimizing processing factors such as the viscosity of the suspension and particle size, as well as the prevention of particle agglomeration and sedimentation during printing, comprising the choice of a suitable debinding and sintering mode. The presented review provides a detailed overview of the recent trends in preparing routes for zirconium oxide bodies; from preparing the suspension through printing and sintering to characterizing mechanical properties. Additionally, the review offers insight into applications of zirconium-based ceramics. Full article
(This article belongs to the Special Issue Advances in Ceramics, 2nd Edition)
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16 pages, 5382 KiB  
Article
Evaluation of the Mechanical Properties and Fatigue Resistance of the ZrO2CeYAl2O3 Composite
by Marcio Paulo de Araújo Mafra, Nélio Silva Júnior, Claudinei dos Santos, Jorge Luiz de Almeida Ferreira, José Alexander Araújo and Cosme Roberto Moreira da Silva
Ceramics 2024, 7(4), 1600-1615; https://doi.org/10.3390/ceramics7040103 - 31 Oct 2024
Viewed by 542
Abstract
This work aimed to evaluate the fatigue limit of the zirconia ceramic composite stabilized with yttria and ceria reinforced with alumina platelets (ZrO2CeYAl2O3) and characterize the mechanical properties of sintered specimens. Bar-shaped specimens were compacted by uniaxial [...] Read more.
This work aimed to evaluate the fatigue limit of the zirconia ceramic composite stabilized with yttria and ceria reinforced with alumina platelets (ZrO2CeYAl2O3) and characterize the mechanical properties of sintered specimens. Bar-shaped specimens were compacted by uniaxial pressing in a rigid die and sintered at 1500 °C-2 h. Subsequent characterizations included quantitative phase analysis by X-ray diffractometry, determination of density, modulus of elasticity, microhardness, fracture toughness, four-point flexural strength, and fatigue limit. Observations of fracture mechanisms were carried out using confocal and scanning electron microscopy (SEM). The sintered samples presented values above 98% of relative density. Complex microstructures with equiaxed, homogeneously distributed submicrometer grains and planar alumina platelets were observed by SEM. The composite samples showed high values of fracture toughness due to the transformation, during the test, from the tetragonal to monoclinic phase, causing an increase in volume and creating compression zones around the crack, making it difficult to propagate. The average flexural strength reached 445.55 MPa, with a Weibull modulus (m = 16.8), revealing low flexural rupture stress data dispersion. In the composite evaluated in this work, the occurrence of the tetragonal → monoclinic transformation that occurs in the Ce-TZP present at the triple points and grain boundaries during cyclic loading produces “crack tip shielding”, that is, a restricted elastic zone (zone shielding) that surrounds the crack tip. This phenomenon leads to a reduction in the stress intensity factor at the tip of the crack and slows down its growth, generating an increase in the fatigue resistance of the composite. Full article
(This article belongs to the Special Issue Mechanical Behavior and Reliability of Engineering Ceramics)
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16 pages, 4419 KiB  
Technical Note
Geopolymers for Space Applications Part II: Synthesis and Physical Characterization
by David Mendoza-Cachú, Aldo Augusto López-Martínez and Edgar A. Franco-Urquiza
Ceramics 2024, 7(4), 1584-1599; https://doi.org/10.3390/ceramics7040102 - 30 Oct 2024
Viewed by 520
Abstract
This Technical Note presents the continuation of the results regarding the synthesis, and physical and rheological evaluation of geopolymers for space applications. In the first part, the ability of these geopolymers to resist cosmic radiation was evaluated. This second part of the research [...] Read more.
This Technical Note presents the continuation of the results regarding the synthesis, and physical and rheological evaluation of geopolymers for space applications. In the first part, the ability of these geopolymers to resist cosmic radiation was evaluated. This second part of the research aims to present the synthesis of the geopolymers, their physical and rheological evaluation, and the fabrication of panels for placement in nanosatellites and deployer systems. Manufacturing the 2 mm-thick geopolymer panel proved to be quite a challenge due to the nature of geopolymers. Three geopolymer formulations MKG-01, MKG-02, and MKG-03 were synthesized with an adequate balance of fluidity and malleability required to manufacture the panels. The formulations offered an open window of approximately 8 h. The mass loss in the formulations was closely related to the solid/liquid ratio of the formulation. The MKG-01 presented lower viscosity and low shear stress for handling, indicating a more homogeneous dispersion than the more viscous samples MKG-02 and MKG-03. Full article
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19 pages, 19095 KiB  
Article
Reactive Spark Plasma Sintering and Oxidation of ZrB2-SiC and ZrB2-HfB2-SiC Ceramic Materials
by Elizaveta P. Simonenko, Eugeniy K. Papynov, Oleg O. Shichalin, Anton A. Belov, Ilya A. Nagornov, Tatiana L. Simonenko, Philipp Yu. Gorobtsov, Maria A. Teplonogova, Artem S. Mokrushin, Nikolay P. Simonenko and Nikolay T. Kuznetsov
Ceramics 2024, 7(4), 1566-1583; https://doi.org/10.3390/ceramics7040101 - 29 Oct 2024
Viewed by 505
Abstract
This study presents the fabrication possibilities of ultra-high-temperature ceramics of ZrB2-30 vol.%SiC and (ZrB2-HfB2)-30 vol.% SiC composition using the reaction spark plasma sintering of composite powders ZrB2(HfB2)-(SiO2-C) under two-stage heating conditions. [...] Read more.
This study presents the fabrication possibilities of ultra-high-temperature ceramics of ZrB2-30 vol.%SiC and (ZrB2-HfB2)-30 vol.% SiC composition using the reaction spark plasma sintering of composite powders ZrB2(HfB2)-(SiO2-C) under two-stage heating conditions. The phase composition and microstructure of the obtained ceramic materials have been subjected to detailed analysis, their electrical conductivity has been evaluated using the four-contact method, and the electron work function has been determined using Kelvin probe force microscopy. The thermal analysis in the air, as well as the calcination of the samples at temperatures of 800, 1000, and 1200 °C in the air, demonstrated a comparable behavior of the materials in general. However, based on the XRD data and mapping of the distribution of elements on the oxidized surface (EDX), a slightly higher oxidation resistance of the ceramics (ZrB2-HfB2)-30 vol.% SiC was observed. The I-V curves of the sample surfaces recorded with atomic force microscopy demonstrated that following oxidation in the air at 1200 °C, the surfaces of the materials exhibited a marked reduction in current conductivity due to the formation of a dielectric layer. However, data obtained from Kelvin probe force microscopy indicated that (ZrB2-HfB2)-30 vol.% SiC ceramics also demonstrated enhanced resistance to oxidation. Full article
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12 pages, 5836 KiB  
Article
The Fabrication of Lithium Niobate Nanostructures by Solvothermal Method for Photocatalysis Applications: A Comparative Study of the Effects of Solvents on Nanoparticle Properties
by Mohd Al Saleh Alothoum and Chawki Awada
Ceramics 2024, 7(4), 1554-1565; https://doi.org/10.3390/ceramics7040100 - 28 Oct 2024
Viewed by 483
Abstract
In this work, we report, for the first time, a comparative study on the effects of different solvents on the properties of LiNbO3 (LN) nanostructures. The solvothermal synthesis method was successfully used with three different solvents: 1—water, 2—methanol, and 3—benzyl. The structural [...] Read more.
In this work, we report, for the first time, a comparative study on the effects of different solvents on the properties of LiNbO3 (LN) nanostructures. The solvothermal synthesis method was successfully used with three different solvents: 1—water, 2—methanol, and 3—benzyl. The structural and optical properties of the as-prepared nanoparticles were studied using transmission electron microscopy (TEM), X-ray diffraction (XRD), UV-Vis absorbance, Raman spectroscopy, and photoluminescence (PL). Nanoparticles of a very small size, with an average size between 3 and 10 nm, were obtained for the first time. The photocatalytic activities of the three synthesized LiNbO3 nanoparticles were studied in relation to the photodegradation of a complex and heavy reactive black 5 dye for a wastewater treatment application. The LiNbO3 synthesized with deionized water showed a higher photocatalytic activity than those synthesized using other solvents, such as methanol or benzyl. Full article
(This article belongs to the Special Issue Advances in Ceramics, 2nd Edition)
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21 pages, 7623 KiB  
Article
The Effect of Adding Banana Fibers on the Physical and Mechanical Properties of Mortar for Paving Block Applications
by Ginan Al-Massri, Hassan Ghanem, Jamal Khatib, Samer El-Zahab and Adel Elkordi
Ceramics 2024, 7(4), 1533-1553; https://doi.org/10.3390/ceramics7040099 - 23 Oct 2024
Cited by 1 | Viewed by 745
Abstract
Paving blocks might encounter diverse environmental conditions during their lifespan. The durability of paving blocks is determined by their capacity to endure various exposure conditions. Synthetic fibers have been used in mortar and concrete to improve their properties. This research investigates the influence [...] Read more.
Paving blocks might encounter diverse environmental conditions during their lifespan. The durability of paving blocks is determined by their capacity to endure various exposure conditions. Synthetic fibers have been used in mortar and concrete to improve their properties. This research investigates the influence of including banana fiber (BF) on the physical and mechanical characteristics of mortar. Five different mortar mixes were developed, with varying amounts of BF ranging from 0 to 2% by volume. Testing included ultrasonic pulse velocity, compressive strength, flexural strength, total water absorption, and sorptivity. Specimens were cured for up to 90 days. The results indicate that using 0.5% BF resulted in an improvement in compressive and flexural strength compared to the control mix. There was an increase in total water absorption and the water absorption coefficient in the presence of fibers. There appeared to be good correlations between the compressive strength and the other properties examined. Full article
(This article belongs to the Special Issue Ceramics in the Circular Economy for a Sustainable World)
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20 pages, 6177 KiB  
Article
Characterization of the Evolution with Temperature of the Structure and Properties of Geopolymer-Cordierite Composites
by Franklin Casarrubios, Alexandre Marlier, Charlotte Lang, Sandra Abdelouhab, Isabella Mastroianni, Geoffroy Bister and Maurice-François Gonon
Ceramics 2024, 7(4), 1513-1532; https://doi.org/10.3390/ceramics7040098 - 17 Oct 2024
Viewed by 613
Abstract
This work is part of a research project aimed at producing ceramic-like materials, without the need for an initial sintering, for potential applications in catalysis or filtration at temperatures up to 1000 °C. In that context, cordierite-derived materials were prepared from recycled cordierite [...] Read more.
This work is part of a research project aimed at producing ceramic-like materials, without the need for an initial sintering, for potential applications in catalysis or filtration at temperatures up to 1000 °C. In that context, cordierite-derived materials were prepared from recycled cordierite powder (automotive industry waste) bonded with metakaolin-potassium silicate geopolymer. The principle is that these materials, prepared at temperatures below 100 °C, acquire their final properties during the high-temperature commissioning. The focus is on the influence of the K/Al ratio and cordierite fraction on the stability of the dimensions and porosity during heating at 1000 °C, and on the final Young’s modulus and coefficient of thermal expansion. Conventional and high-temperature XRD evidenced the absence of crystallization of the geopolymer binder and interaction with the cordierite filler during the heating stage when K/Al = 1 or 0.75. By contrast, crystallization of kalsilite and leucite, and diffusion of potassium ions in the structure of cordierite is evidenced for K/Al = 1.5 and 2.3. These differences strongly influence the shrinkage due to sintering and the final properties. It is shown that a K/Al ratio of 0.75 or 1 is favorable to the stability of the porosity, around 25 to 30%. Moreover, a low coefficient of thermal expansion of 4 to 4.5 × 10−6 K−1 and a Young’s modulus of 40 to 45 GPa is obtained. Full article
(This article belongs to the Special Issue Innovative Manufacturing Processes of Silicate Materials)
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13 pages, 10644 KiB  
Article
Ultraviolet-Sensor Based on Tin-Doped Zinc Oxide Thin Films Grown by Spray Pyrolysis
by Matías Valdés, Edgar A. Villegas, Leandro A. Ramajo and Rodrigo Parra
Ceramics 2024, 7(4), 1500-1512; https://doi.org/10.3390/ceramics7040097 - 14 Oct 2024
Viewed by 485
Abstract
The development of sensors that can monitor ultraviolet radiation has many implications for daily life, and even more so if the focus is on low-cost solution processes and the use of eco-friendly materials. In this study, we produced a UV-sensor based on Sn-doped [...] Read more.
The development of sensors that can monitor ultraviolet radiation has many implications for daily life, and even more so if the focus is on low-cost solution processes and the use of eco-friendly materials. In this study, we produced a UV-sensor based on Sn-doped ZnO thin films grown by spray pyrolysis, with a doping content ranging from 1 to 10 at.%. The study focuses on the characterization of the films and the device, and their potential for UV detection. Structural analysis via XRD, FESEM, and STEM confirms the polycrystalline nature of the films, with a hexagonal single-phase wurtzite structure of ZnO. Although the dopant content in the films was widely varied, optoelectronic properties such as transmittance, resistivity, energy gap, density, and carrier mobility are not significantly modified. Sprayed Sn-doped ZnO films demonstrated high sensitivity to ultraviolet light, whether monochromatic or that coming from solar radiation. Outdoor measurements showed promising performance of the UV-sensor, indicating its potential applicability for real-time UV monitoring and potential use. Overall, sprayed Sn-doped ZnO thin films offer a viable and low-cost solution for the fabrication of UV-sensors with desirable properties such as a wide and direct bandgap, high sensitivity, and ease of fabrication. Full article
(This article belongs to the Special Issue Research Progress in Ceramic Coatings)
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12 pages, 3209 KiB  
Article
Mullite–Silicate Proppants Based on High-Iron Bauxite and Waste from Metallurgical Industry in Kazakhstan
by Tolebi Dzhienalyev, Alla Biryukova, Bagdaulet Kenzhaliyev, Alma Uskenbaeva and Galiya Ruzakhunova
Ceramics 2024, 7(4), 1488-1499; https://doi.org/10.3390/ceramics7040096 - 14 Oct 2024
Viewed by 543
Abstract
The suitability of microsilica as a raw material for the production of ceramic mullite–silicate proppants was assessed. The chemical and mineralogical compositions of the initial materials were studied. The mineral composition of bauxite is mainly represented by gibbsite Al(OH)3 and, to a [...] Read more.
The suitability of microsilica as a raw material for the production of ceramic mullite–silicate proppants was assessed. The chemical and mineralogical compositions of the initial materials were studied. The mineral composition of bauxite is mainly represented by gibbsite Al(OH)3 and, to a lesser extent, kaolinite Al4[Si4O10](OH)8, with impurities of hematite and quartz. It is established that, in order to obtain mullite–silicate proppants, compositions containing 10–20% microsilica are optimal. The sintering of these compositions occurs at 1350–1380 °C. A lightweight ceramic proppant was obtained with a bulk density of 1.21–1.41 g/cm3, breaking ratio at 51.7 MPa of 19.1–20.3%, and sphericity and roundness of 0.7–0.9, and the optimal roasting temperature was determined as 1370–1380 °C. Full article
(This article belongs to the Special Issue Ceramics in the Circular Economy for a Sustainable World)
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11 pages, 4809 KiB  
Article
Binderless Polycrystalline Cubic Boron Nitride Sintered Compacts for Machining of Cemented Carbides
by Alexander S. Osipov, Piotr Klimczyk, Igor A. Petrusha, Yurii O. Melniichuk, Lucyna Jaworska, Kinga Momot and Yuliia Rumiantseva
Ceramics 2024, 7(4), 1477-1487; https://doi.org/10.3390/ceramics7040095 - 13 Oct 2024
Viewed by 653
Abstract
High-purity, superhard, binderless polycrystalline cubic boron nitride (BL-PCBN) was obtained by direct hBN to cBN transformation in a toroid-type high-pressure apparatus at a pressure of 8.0 GPa and temperature of 2250 °C (HPHT-DCS; high-pressure, high-temperature direct conversion sintering). X-ray diffraction analysis revealed a [...] Read more.
High-purity, superhard, binderless polycrystalline cubic boron nitride (BL-PCBN) was obtained by direct hBN to cBN transformation in a toroid-type high-pressure apparatus at a pressure of 8.0 GPa and temperature of 2250 °C (HPHT-DCS; high-pressure, high-temperature direct conversion sintering). X-ray diffraction analysis revealed a prominent [111] axial texture in the sintered material when the axis was oriented perpendicular to the end surface of the sample. Vickers hardness tests conducted at a load of 49 N showed that BL-PCBN possessed an exceptional hardness value of 63.4 GPa. Finally, cutting tools made of BL-PCBN and SN-PCBN (Si3N4-doped cBN-based composite) reference materials were tested during the turning of a cemented tungsten carbide workpiece. The results of the cutting tests demonstrated that the wear resistance of the BL-PCBN material obtained with the HPHT-DCS process is 1.5–1.9 times higher compared to the conventional SN-PCBN material, suggesting its significant potential for industrial application. Full article
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18 pages, 6591 KiB  
Article
Bioactive-Glass-Incorporated Plasma Electrolytic Oxidation Coating on AZ31 Mg Alloy: Preparation and Characterization
by Syed Ahmed Uzair, Fayaz Hussain and Muhammad Rizwan
Ceramics 2024, 7(4), 1459-1476; https://doi.org/10.3390/ceramics7040094 - 12 Oct 2024
Viewed by 925
Abstract
Magnesium alloys, despite having a number of attractive properties, encounter difficulties in clinical applications due to their rapid degradation rate in the physiological environment. In this work, a Bioglass (BG)-incorporated plasma electrolytic oxidation (PEO) coating was applied on the AZ31 Mg alloy to [...] Read more.
Magnesium alloys, despite having a number of attractive properties, encounter difficulties in clinical applications due to their rapid degradation rate in the physiological environment. In this work, a Bioglass (BG)-incorporated plasma electrolytic oxidation (PEO) coating was applied on the AZ31 Mg alloy to overcome this major limitation. PEO treatment was carried out in constant current mode with and without the addition of BG particles. The effects of BG particles on the coating’s morphology, composition, adhesion, electrochemical corrosion resistance and bioactivity were analyzed. SEM micrographs revealed that BG submicron particles were well adhered to the surface and the majority of them were entrapped in the micropores. Furthermore, the adhesion strength of the coated layer was adequate—a maximum value of 22.5 N was obtained via a micrometer scratch test. Potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) results revealed that the degradation rate of the Mg alloy was slowed down by up to 100 times, approximately. Moreover, the PEO–BG layer considerably enhanced the in vitro bioactivity of the Mg alloy in a simulated body fluid (SBF) environment; a prominent apatite layer was witnessed through SEM imaging. Consequently, the BG-incorporated PEO layer on Mg AZ31 alloy exhibited some promising outcomes and, therefore, can be considered for biomedical applications. Full article
(This article belongs to the Special Issue Research Progress in Ceramic Coatings)
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19 pages, 8953 KiB  
Article
Synthesis of Magnesia–Hercynite-Based Refractories from Mill Scale and Secondary Aluminum Dross: Implication for Recycling Metallurgical Wastes
by Praphaphan Wongsawan, Nantiya Boonlom, Muenfahn Vantar and Somyote Kongkarat
Ceramics 2024, 7(4), 1440-1458; https://doi.org/10.3390/ceramics7040093 - 5 Oct 2024
Viewed by 619
Abstract
This study investigates the synthesis of magnesia–hercynite-based refractories using blends of magnesia powder, aluminum dross (AD), mill scale (MS), and graphite, focusing on the effects of carbon concentration and heating temperature. The results demonstrate successful synthesis at 1550 °C and 1650 °C, with [...] Read more.
This study investigates the synthesis of magnesia–hercynite-based refractories using blends of magnesia powder, aluminum dross (AD), mill scale (MS), and graphite, focusing on the effects of carbon concentration and heating temperature. The results demonstrate successful synthesis at 1550 °C and 1650 °C, with high magnesia content (C80 and D80) leading to the formation of distinct phases, including MgO, FeAl2O4, MgFeAlO4, CaMg(SiO4), and Ca3Mg(SiO4)2, which influence the ceramic’s microstructure and mechanical properties. Increased magnesia content reduces porosity and enhances crushing strength, while heating to 1650 °C significantly improves densification and nearly doubles cold crushing strength, from 43.77–58.97 MPa at 1550 °C to 76.79–95.67 MPa at 1650 °C. These findings suggest that the synthesized refractories exhibit properties comparable to commercial magnesia–hercynite bricks, with potential for the further development for industrial rotary kiln applications. Full article
(This article belongs to the Special Issue Ceramics in the Circular Economy for a Sustainable World)
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27 pages, 11774 KiB  
Article
Novel Ceramic Clay Automatic Feeding System and Simulation Analysis
by Xunchen Liu, Yilun Wang, Bo Mu, Hailin Wu, Lanxin Wang, Mingzhang Chen and Shanyue Guan
Ceramics 2024, 7(4), 1413-1439; https://doi.org/10.3390/ceramics7040092 - 4 Oct 2024
Viewed by 572
Abstract
This study aims to verify the feasibility and effectiveness of an automatic feeding system in the ceramic clay-forming process. Through a series of clay-forming experiments, the system’s performance under various process parameters was examined. Precision sensors and data recording devices were used to [...] Read more.
This study aims to verify the feasibility and effectiveness of an automatic feeding system in the ceramic clay-forming process. Through a series of clay-forming experiments, the system’s performance under various process parameters was examined. Precision sensors and data recording devices were used to monitor and record key data during the experimental process in real-time. The results demonstrate that the automatic feeding system can supply clay steadily and continuously under set parameters, ensuring a smooth forming process and significantly improving efficiency. Quantitatively, the system achieved a 30% increase in Vickers hardness, reflecting enhanced mechanical properties of the formed clay bodies. Additionally, there was a notable improvement in axial stress–strain characteristics, indicating better structural integrity and consistency. These improvements reduced human errors and material waste, enhancing production efficiency and product quality. Future research will focus on further optimizing system design and exploring its applications in a broader range of ceramic manufacturing processes. Full article
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12 pages, 8394 KiB  
Article
Features of Dielectric Properties of 0.20BiScO3·0.45PbTiO3·0.35PbMg1/3Nb2/3O3 Samples Obtained by the Melt-Hardening Method
by A. A. Nogai, A. S. Nogai, D. E. Uskenbaev and E. A. Nogai
Ceramics 2024, 7(4), 1401-1412; https://doi.org/10.3390/ceramics7040091 - 4 Oct 2024
Viewed by 570
Abstract
This paper studies the structural parameters and electrophysical properties (dielectric and piezo electric, as well as currents of thermostimulated depolarization) of samples of composition 0.20BiScO3·0.45PbTiO3·0.35PbMg1/3Nb2/3O3 (or in short 0.20BS·0.45PT·0.35PMN) obtained by ceramic and melt-hardening [...] Read more.
This paper studies the structural parameters and electrophysical properties (dielectric and piezo electric, as well as currents of thermostimulated depolarization) of samples of composition 0.20BiScO3·0.45PbTiO3·0.35PbMg1/3Nb2/3O3 (or in short 0.20BS·0.45PT·0.35PMN) obtained by ceramic and melt-hardening methods of synthesis. In the ceramic method, the samples were obtained from the starting oxides by two-stage firing. In the melt method, amorphous precursors were first obtained from heat-treated and non-heat-treated starting oxide mixtures by melting and subsequent quenching under sharply gradient temperature conditions. Samples were obtained after grinding, pressing, and thermal annealing of the synthesized precursors, and four types of samples differing in size and shape of the intermediate precursor particles (crystallites) were obtained. The X-ray phase analysis showed that the predominant phase in the studied samples is the perovskite phase; in both types of samples, up to 5 wt.% of impurity phase with pyrochlore structure was also present. The samples of 0.20BS·0.45PT·0.35PMN exhibit dielectric properties characteristic of relaxor ferroelectrics, and the polarized samples exhibit a pronounced piezo effect with a piezo modulus value of d33~200 pC/N. A comparative analysis of the properties of the samples obtained by different methods has been carried out. The essential advantage of the melt method is that its use allows obtaining varieties of four kinds of ferroelectric relaxors and reduces the time of synthesis of samples by 2–3 times. Full article
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11 pages, 4584 KiB  
Article
Microstructure and Mechanical Properties of Diamond–Ceramic Composites Fabricated via Reactive Spark Plasma Sintering
by Yunwei Shi, Lanxin Hu, Aiyang Wang, Chun Liu, Qianglong He and Weimin Wang
Ceramics 2024, 7(4), 1390-1400; https://doi.org/10.3390/ceramics7040090 - 2 Oct 2024
Viewed by 744
Abstract
In order to prepare diamond composites with excellent mechanical properties under non-extreme conditions, in this study, a diamond–ceramic composite was successfully prepared via reactive spark plasma sintering using a diamond–Ti–Si powder mixture as the raw material. The microstructures and mechanical properties of the [...] Read more.
In order to prepare diamond composites with excellent mechanical properties under non-extreme conditions, in this study, a diamond–ceramic composite was successfully prepared via reactive spark plasma sintering using a diamond–Ti–Si powder mixture as the raw material. The microstructures and mechanical properties of the diamond–ceramic composite sintered at different temperatures were studied. When the sintering temperature was 1500 °C, the diamond–ceramic composite exhibited a volume density of 3.65 g/cm3, whereas the bending strength and fracture toughness were high at 366 MPa and 6.17 MPa·m1/2, respectively. In addition, variable-temperature sintering activated the chemical reaction at a higher temperature, whereas lowering the temperature prevented excessive graphitisation, which is conducive to optimising the microstructure and mechanical properties of the composite. Full article
(This article belongs to the Special Issue Mechanical Behavior and Reliability of Engineering Ceramics)
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25 pages, 3036 KiB  
Review
Recent Advances in High-Entropy Ceramics: Synthesis Methods, Properties, and Emerging Applications
by Piyush Chandra Verma, Sunil Kumar Tiwari, Ashish Saurabh and Abhinav Manoj
Ceramics 2024, 7(4), 1365-1389; https://doi.org/10.3390/ceramics7040089 - 30 Sep 2024
Viewed by 936
Abstract
High-entropy ceramics (HECs) represent an emerging class of materials composed of at least five different cations or anions in near-equiatomic proportions, garnering significant attention due to their extraordinary functional and structural properties. While multi-component ceramics have played a crucial role for many years, [...] Read more.
High-entropy ceramics (HECs) represent an emerging class of materials composed of at least five different cations or anions in near-equiatomic proportions, garnering significant attention due to their extraordinary functional and structural properties. While multi-component ceramics have played a crucial role for many years, the concept of high-entropy materials was first introduced eighteen years ago with the synthesis of high-entropy alloys, and the first high-entropy nitride films were reported in 2014. These newly developed materials exhibit superior properties over traditional ceramics, such as enhanced thermal stability, hardness, and chemical resistance, making them suitable for a wide range of applications. High-entropy carbides, borides, oxides, oxi-carbides, oxi-borides, and other systems fall within the HEC category, typically occupying unique positions within phase diagrams that lead to novel properties. HECs are particularly well suited for high-temperature coatings, for tribological applications where low thermal conductivity and similar heat coefficients are critical, as well as for energy storage and dielectric uses. Computational tools like CALPHAD streamline the element selection process for designing HECs, while innovative, energy-efficient synthesis methods are being explored for producing dense specimens. This paper provides an in-depth analysis of the current state of the compositional design, the fabrication techniques, and the diverse applications of HECs, emphasizing their transformative potential in various industrial domains. Full article
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25 pages, 7184 KiB  
Article
Furnace Testing and Validation of a Hybrid Cooling Approach for Enhanced Turbine Blade Protection with a Thermal Barrier Coating in Advanced Gas Turbines
by Salmi Mohd Yunus, Abreeza Manap, Meenaloshini Satgunam, Savisha Mahalingam and Nurfanizan Mohd Afandi
Ceramics 2024, 7(4), 1340-1364; https://doi.org/10.3390/ceramics7040088 - 27 Sep 2024
Viewed by 610
Abstract
Hybrid turbine blade protection systems, which combine thermal barrier coatings (TBCs) and cooling mechanisms, are essential for safeguarding turbine blades in advanced gas turbine applications. However, conventional furnace evaluation methods are inadequate for accurately simulating the complex thermal conditions experienced by TBCs in [...] Read more.
Hybrid turbine blade protection systems, which combine thermal barrier coatings (TBCs) and cooling mechanisms, are essential for safeguarding turbine blades in advanced gas turbine applications. However, conventional furnace evaluation methods are inadequate for accurately simulating the complex thermal conditions experienced by TBCs in these environments. Initial testing revealed substantial degradation of TBCs when subjected to high temperatures without the necessary cooling support. To address this limitation, the furnace setup was modified to incorporate a cooling air system. This system channeled 400 °C air to the back surface of the TBC while subjecting the front to 1400 °C furnace air, effectively replicating the thermal gradient encountered in hybrid protection systems. The modified furnace setup demonstrated a remarkable improvement in the performance of yttria-stabilized zirconia TBCs. By cooling the back surface of the TBC, the metal substrate temperature decreased, thereby improving the thermal gradient on the coating and its durability. The thermal gradient achieved by the modified furnace was verified to simulate accurately the conditions experienced by TBCs in advanced gas turbines. The conventional furnace setup, lacking a cooling mechanism, overestimated the heat transfer on the TBCs, leading to inaccurate results. The modified furnace, with its integrated cooling system, more accurately simulated the conditions experienced by TBCs in real-world advanced gas turbine applications and more reliably assessed their performance. Full article
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24 pages, 14405 KiB  
Article
Advanced Refinement of Geopolymer Composites for Enhanced 3D Printing via In-Depth Rheological Insights
by Abrar Gasmi, Christine Pélegris, Ralph Davidovits, Mohamed Guessasma, Hugues Tortajada and Florian Jean
Ceramics 2024, 7(4), 1316-1339; https://doi.org/10.3390/ceramics7040087 - 27 Sep 2024
Cited by 1 | Viewed by 795
Abstract
The advancement of 3D printing technology has been remarkable, yet the quality of printed prototypes heavily relies on the rheological behavior of the materials used. This study focuses on optimizing geopolymer-based composite formulas to achieve high-quality 3D printing, with particular attention given to [...] Read more.
The advancement of 3D printing technology has been remarkable, yet the quality of printed prototypes heavily relies on the rheological behavior of the materials used. This study focuses on optimizing geopolymer-based composite formulas to achieve high-quality 3D printing, with particular attention given to rheological analysis. Three metakaolins, Argical M1200s, Metamax, and Tempozz M88, were used as alumino-silicate precursors for the preparation of the geopolymer binders. Rheological studies were conducted on viscosity, shear stress, and responses to oscillations in amplitude and frequency. The Tempozz M88-based binder was identified as the most effective for the extrusion due to its optimal rheological properties. Subsequently, the study investigated the influence of the amount, up to 55%, and morphology of the fillers, comprising feldspar and wollastonite, on the rheology of the pastes. Also, the addition of Xanthan gum, a gelling agent in the geopolymer paste, was analyzed, revealing improved extrusion quality and more stable bead structures. Finally, a comprehensive comparison was carried out between two formulations chosen according to rheological observations, utilizing image sequences captured during 3D printing. This comparison highlighted the formulation that ensures structural stability, design accuracy, and minimized sagging. This study underscores the significance of geopolymer formula optimization, leveraging rheology as a pivotal tool to enhance 3D printing quality, thereby facilitating more precise and reliable applications of additive manufacturing. Full article
(This article belongs to the Special Issue Innovative Manufacturing Processes of Silicate Materials)
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15 pages, 6799 KiB  
Article
Hardening of Mortars from Blended Cement with Opoka Additive in CO2 Environment
by Raimundas Siauciunas, Edita Prichockiene, Zenonas Valancius and Arunas Elsteris
Ceramics 2024, 7(4), 1301-1315; https://doi.org/10.3390/ceramics7040086 - 26 Sep 2024
Viewed by 515
Abstract
The influence of the parameters of accelerated carbonization in a 99.9% CO2 environment on the hardening kinetics of blended cement with 15 wt% opoka additive, the physical and mechanical properties of the resulting products, the mineralogical composition, and the amount of absorbed [...] Read more.
The influence of the parameters of accelerated carbonization in a 99.9% CO2 environment on the hardening kinetics of blended cement with 15 wt% opoka additive, the physical and mechanical properties of the resulting products, the mineralogical composition, and the amount of absorbed CO2 were investigated. Sedimentary rock opoka was found to have opal silica and calcite as its predominant constituent parts. Therefore, these properties determine that it serves as an extremely suitable raw material and a source of both SiO2 and CaO. The strength properties of the mortars (blended cement/standard sand = 1:3) were similar or even better than those of samples based on Ordinary Portland cement (OPC): the compressive strength exceeded 50 MPa under optimal conditions. In blended cement, some of the pores are filled with fine-dispersed opoka, which can lead to an increase in strength. By reducing the amount of OPC in mixtures, the negative impact of its production on the environment is reduced accordingly. Using XRD, DSC, and TG methods, it was determined that replacing 15 wt% of OPC clinker with opoka does not affect the mineralogy of the crystalline phases as the same compounds are obtained. After determining the optimal parameters for sample preparation and hardening, in accordance with the obtained numbers, concrete pavers of industrial dimensions (100 × 100 × 50 mm) were produced. Their strength indicators were even ~10% better. Full article
(This article belongs to the Special Issue Ceramic Materials for Industrial Decarbonization)
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