Search

Purpose: To compare the translucency parameters and masking abilities of different monolithic CAD/CAM ceramics placed on different-colored substructures. Materials and Methods: Square-shaped specimens (12 × 12 × 1.5 mm) were prepared from feldspathic (C), leucite (EMP), lithium disilicate (e.max), zirconiareinforced lithium silicate (VS), resin nanoceramic (LU), polymer-infiltrated ceramic (VE), hybrid nanoceramic (GC), monolithic zirconia (TZI), and composite resin (TC) blocks (n = 10 per material). After mechanical polishing, the translucency parameter (TP) was calculated. Then, each ceramic specimen was measured on eight substructures, and the color difference between ND2 and each substrate was calculated with the CIEDE2000 formula. TP values were analyzed with one-way ANOVA and Games-Howell tests, and the color differences indicating masking ability were analyzed with two-way ANOVA and Tukey HSD tests. Results: The highest TP was observed in TC, followed by LU, EMP, C,GC, e.max, VS, VE, and TZI. The E00 color difference values of TZI, VS, and VE on all abutment colors, except for ND9, were below the acceptable threshold value. Conclusions: All monolithic ceramic materials used in the study masked the ND1 and ND3 substrates. The ND9, representing severely discolored or devitalized preparations, could not be masked by any monolithic CAD/CAM ceramics used in the study. [ABSTRACT FROM AUTHOR]

Purpose: To compare the masking ability of monolithic CAD/CAM veneers placed over different resin cement shades and substrate colors. Materials and Methods: Veneers were milled from four different monolithic CAD/CAM restorative materials: feldspathic ceramic (VMII), lithium disilicate ceramic (Emax CAD), zirconiareinforced lithium silicate ceramic (VS), and high-translucency zirconia ceramic (YZ-XT). Veneers were luted on natural tooth-colored (ND1) or discolored substrates (ND3 or ND5) using two different resin cement shades (opaque white or translucent). Each CAD/CAM material, resin cement shade, and substrate combination comprised 9 sample veneers (N = 216). Color parameters were obtained using a dental spectrophotometer before and after luting. Color differences (E00) were calculated using CIEDE2000 formula and compared to perceptibility (P = .81 E00 units) and acceptability (AT = 1.77 E00 units) visual thresholds. Color variation data were statistically analyzed using Kruskal-Wallis and Mann-Whitney U tests with Bonferroni-Holm correction (a = .05). Results: The highest E00 value was obtained in the VMII group placed over a discolored substrate, followed by the Emax CAD, YZ-XT, and VS groups. The effect of material types on E00 values was significantly observed when the veneers were luted on discolored substrates using translucent resin cement (P < .05). Conclusions: Restorative material type, substrate color, and resin cement shade affect the masking ability of monolithic CAD/CAM laminate veneers. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate inlay and onlay marginal adapta2on of two different ceramic materials using two intracoronal prepara2on designs. Materials and Methods: An examina2on of the marginal adap2on of two materials--lithium disilicate (LD; IPS e.max CAD) and polymer infiltrated ceramic network material (PICN; Vita Enamic)--and two prepara2on designs, where D1 represents MOD inlay prepara2on with no cusp reduc2on and for D2, in addi2on to the basic MOD prepara2on, the buccal cusps (func2onal cusps) were reduced by 1.5 mm. Four sub-groups (LD-D1, LD-D2, PICN-D1, PICN-D2) were conducted. In total, 40 (n = 40) mandibular molars were used. A stereomicroscope was used to assess the marginal gap before, aWer cementa2on and aWer thermocycling. Values were calculated for the mean, median, SD, minimum, maximum, and 95% CI. Pairwise comparisons using Tukey post-hoc test were performed following an ANOVA significance of P = .05. Results: The results revealed that lithium disilicate showed sta2s2cally significantly higher mean gap distance than PICN material (61 µm to 99 µm). Pairwise comparisons showed that D2 design has sta2s2cally significant higher mean gap values than D1. Conclusions: Both LD and PICN material provided marginal adapta2on within clinical accepted range. PICN material restora2ons provided beer fit than lithium disilicate restora2ons. Cusp coverage has a greater marginal gap compared to conven2onal prepara2on. [ABSTRACT FROM AUTHOR]

Ceramic materials are widely used in armor or protective structures, providing weight saving at equivalent performance in comparison to their steel counterparts. Plate-impact experiments are commonly used to investigate the dynamic behavior of ceramics under compressive loading. Using the particle velocity measured at the back of the target, some mechanical properties such as the Hugoniot elastic limit (HEL) as well as the Hugoniot curve of the material can be deduced. Nevertheless, these tests do not provide a direct measurement of the plastic hardening (post-HEL) behavior of the target. In the present work, an experimental shockless plate-impact configuration was developed and implemented to conduct a Lagrangian analysis. This configuration relies on the use of a wavy-machined flyer plate impacting a target made of a buffer, two ceramic plates of different thicknesses, and two window plates as backing. First, the use of wavy flyer plates to generate a loading ramp was validated by considering the impact of the wavy-machined flyer plate against a target, both made of 316L steel. A numerical analysis of this test was developed to confirm the pulse-shaping effect observed experimentally. Next, a ceramic, F99.7 alumina was subjected to the shockless plate impact test in Lagrangian configuration considering the same steel as a buffer and flyer plate material. These tests coupled with Lagrangian analysis enable the curve of axial-stress vs axial-strain beyond the isentropic elastic limit (IEL) to be deduced. The experimental data allow identifying the parameters of an elastoplastic with strain-hardening model to describe the behavior of the tested alumina. [ABSTRACT FROM AUTHOR]

Purpose: To assess the clinical performance of CAD/CAM laminate veneers placed by a single operator and systematically evaluated for up to 10 years. Materials and Methods: A total of 197 laminate veneers fabricated using either feldspathic ceramics (VMII) or lithium disilicate ceramics (EmaxCAD) were followed up to 10 years in 32 patients. Technical, esthetic, and biologic findings of each restoration were evaluated using modified United States Public Health Service criteria. The survival and complication rates were assessed using Kaplan-Meier survival analysis and compared using log-rank test. Statistical significance was set at P < .05. Results: The estimated Kaplan-Meier survival rate was 91.9% after the mean observation period. According to the ceramic system used, the estimated Kaplan-Meier survival rate amounted to 92.7% for EmaxCAD and 89.1% for VMII. Survival rates were significantly affected by the location of veneer according to log-rank test (P < .05). A range of survival rates between 83.3% and 98.6% were observed based on the location of veneer. Conclusions: CAD/CAM laminate veneers milled from feldspathic or lithium disilicate ceramics have comparable long-term survival rates. Oral positioning affects the survival of veneers. Veneers of incisors have higher survival rates than the veneers of maxillary canines and premolars. [ABSTRACT FROM AUTHOR]

In this study, the influence of ceramic shield characteristics, including thickness and geometry, on the transmission spectrum and electron density measurements of a ceramic shield cutoff probe (CSC) was investigated to measure high-density or process plasma. Through electromagnetic simulations and circuit modeling, we examined the measurement characteristics of the CSC based on different ceramic shield geometries. When the ceramic shield is sufficiently thin, it does not affect the CSC wave transmission characteristics. However, for a thick ceramic shield, a cutoff frequency shift of up to 3% toward the lower side can occur. This shift is attributed to the electrical properties of the ceramic material, which can function as a parasitic capacitor. In addition, when fabricating a CSC, depending on the shape of the ceramic shield or the method used to couple it with the CSC body, a cutoff frequency shift can occur toward the lower side. The simulation results were validated through experiments, revealing a cutoff frequency shift toward the lower side of up to 18.0% in the simulations and up to 11.6% in the experiments. The findings of this study could assist in high-density or processing plasma measurements using cutoff probes. [ABSTRACT FROM AUTHOR]

Extensive experimental and computational studies have demonstrated outstanding physical and chemical properties of the novel materials of compositionally complex carbides (CCCs), enabling their promising applications in advanced fission and fusion energy systems. This perspective provides a comprehensive overview of radiation damage behavior reported in the literature to understand the fundamental mechanisms related to the impact of multi-principal metal components on phase stability, irradiation-induced defect clusters, irradiation hardening, and thermal conductivity of compositionally complex carbides. Several future research directions are recommended to critically evaluate the feasibility of designing and developing new ceramic materials for extreme environments using the transformative "multi-principal component" concept. Compared to the existing materials for nuclear applications including stainless steels, nickel alloys, ZrC, SiC, and potentially high-entropy alloys, as well as certain other compositionally complex ceramic families. CCCs appear to be more resistant to amorphization, growth of irradiation defect clusters, and void swelling. [ABSTRACT FROM AUTHOR]

A series of Sr0.7Ba0.3Nb2O6−δ/x wt. % Ti (x = 1, 3, 5, and 10) composite ceramic thermoelectric materials were prepared, and the mechanism for improving their thermoelectric properties was explored. The experimental results demonstrate that nano-additive titanium powder undergoes oxidation to form TiO2 during sintering. However, under annealing in a reducing atmosphere, oxidation reactions further deplete the lattice oxygen, leading to an increased generation of oxygen vacancies and enhanced carrier concentration, ultimately leading to successful resistivity reduction. The samples consistently exhibit low thermal conductivity values below 2.0 W m−1 K−1 due to crystal defects, complex structure, and phonon scattering at the grain boundaries. The sample doped with 5 wt. %. Ti exhibits the lowest resistivity and highest PF value (409.3 μW/m K2 at 1073 K). Consequently, the figure of merit of Sr0.7Ba0.3Nb2O6−δ with 5 wt. % Ti attains its maximum value of 0.30 at 1073 K, representing a 50% increase compared to that of the undoped sample Sr0.7Ba0.3Nb2O6−δ (0.20 at 1073 K). [ABSTRACT FROM AUTHOR]

Purpose: To investigate the influence of immediate dentin sealing (IDS) vs delayed dentin sealing (DDS) on the marginal gaps of machinable monolithic zirconia vs pressable lithium disilicate laminate veneers.Materials and Methods: A total of 40 maxillary lateral incisors were used and received butt-joint laminate veneer preparation. The samples were divided into two groups (n = 20 each) according to ceramic material: pressable lithium disilicate ceramic (PLD) was used in the first group, and machinable monolithic zirconia (MMZ) was used in the second. Each group was then divided into two subgroups according to the bonding protocol: IDS was employed in one, and DDS in the other (n = 10 each). The marginal gap widths were measured using digital microscopy and statistically analyzed.Results: The smallest marginal gaps were observed in MMZ-DDS (57.2 ± 8.4 μm), followed by PLD-DDS (62.4 ± 2.7 μm) and MMZ-IDS (63.5 ± 1.9 μm). The largest marginal gaps were observed in PLD-IDS (81.5 ± 6.3 μm). Two-way ANOVA revealed that the bonding technique (P < .001) and ceramic material (P < .001) both showed significant differences.Conclusions: MMZ produced better marginal accuracy than PLD. IDS seems to have a predisposition to significantly wider marginal gaps than DDS, but these gaps are within the clinically acceptable range. The marginal accuracy of ceramic veneers appears to be related to the bonding technique as well as the material of construction. [ABSTRACT FROM AUTHOR]

Purpose: To compare the fracture resistance of five different groups of chairside CAD/CAM molar crowns fabricated from various lithium disilicate ceramic materials (LDC): one conventional precrystallized CAD/CAM LDC, two novel precrystallized LDCs, and one fully crystallized LDC tested both with and without optional sintering. Materials and Methods: A total of 60 chairside CAD/CAM lithium disilicate molar crowns (n = 12 per group) with 1.5-mm occlusal thickness and a 1.0-mm chamfer finish were designed and fabricated with a chairside CAD/CAM system (CEREC, Dentsply Sirona). The restorations were divided into five groups: (1) IPS e.max CAD; (2) Amber Mill; (3) Straumann n!ce; (4) Straumann n!ce with optional sintering; and (5) Supreme CAD. Restorations were cemented using conventional resin luting cement and primer system to 3D-printed resin dies. Bonded restorations were loaded for 100,000 cycles with 275-N force, and the load at break (LB) and peak load (PL) until fracture were measured. SEM images of fracture surfaces on the printed dies were obtained. Results: Fracture resistance was significantly different depending on the material. Supreme CAD showed the highest fracture resistance (LB: 1,557.2 N; PL: 1,785.8 N), followed by Amber Mill (LB: 1,393.0 N; PL: 1,604.2 N) and IPS e.max CAD (LB: 1,315.7 N; PL: 1,461.9 N). Straumann n!ce without (LB: 862.4 N; PL: 942.9 N) and with the optional sintering (LB: 490.4 N; PL: 541.0 N) showed significantly lower fracture resistance than the others. Conclusion: The fracture resistance of chairside CAD/CAM lithium disilicate molar crowns varied depending on the material, and the novel materials did not perform as well as the conventional equivalents. Fully crystallized lithium disilicate ceramic block materials showed lower fracture resistance than precrystallized counterparts and should be used with caution in the clinic, especially with optional sintering. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the fracture-behavior of monolithic crowns made of lithium disilicate (IPS e.max CAD, Ivoclar Vivadent; IniBal LiSi Block, GC Dental) and zirconia-reinforced lithium silicate (Celtra Duo, DeguDent; VITA Zahnfabrik) materials before and aKer cyclic faBgue aging. Materials and Methods: Four groups (n = 22/group) of CAD/CAM fabricated upper incisor crowns were produced. All crowns were luted on metal dies with an adhesive dualcure resin cement (G-CEM LinkForce, GC Dental). Half of the crowns in each group (n = 11) were staBcally loaded unBl fracture, without aging. The remaining crowns were subjected to cyclic faBgue aging for 120,000 cycles (Fmax = 220 N) and then loaded staBcally unBl fracture. The fractured models were then visually examined. Scanning electron microsopy (SEM) and energy-dispersive spectroscopy (EDS) were used to evaluate the microstructure of CAD/CAM ceramic materials. The data were staBsBcally analyzed with two-way ANOVA followed by the Tukey HSD test (a = .05). Results: Before cyclic aging, there was no staBsBcally significant difference in load-bearing capacity among the four groups (P = .371). AKer cyclic aging, load-bearing capacity significantly decreased for all groups (P = .000). While the e.max CAD blocks had significantly higher load-bearing capacity (1061 ± 94 N) than both monolithic ceramic crowns (load-bearing capaciBes of the groups) (P < .05), no significant difference was obtained with the IniBal LiSi Block group (920 ± 140 N) (P = .061). Conclusions: The mechanical performance of monolithic ceramic crowns fabricated from lithium disilicate was befer than zirconia-reinforced lithium silicate aKer cyclic faBgue aging. [ABSTRACT FROM AUTHOR]

Many ceramic materials transform to a solid-solution intermediate state before amorphization under extreme conditions. Combining in-situ irradiation experiments and ab initio molecular dynamics simulations, we performed a comparative study of the defect accumulation process in MAX phases, Ti 2 AlC, Cr 2 AlC, and Ti 2 SnC, to clarify the correlation between solid-solution intermediate phase properties and phase instability. It is found that phase stability strongly depends on the lattice distortion of the solid-solution intermediate state, rather than the defect energies in the initial phases that were previously believed as the indicator of the resistance to the irradiation-induced amorphization. Larger lattice distortions of the solid-solution intermediate state can hinder defect recombination and lead to faster collapse to an amorphous state. This work provides a new research insight into phase instability for ceramic materials under extreme conditions. [ABSTRACT FROM AUTHOR]

Applications of praseodymium doped ceria (PDC) in solid oxide fuel cells require a deep insight into the thermal expansion, stresses, and ionic conduction. Nonetheless, the investigation of thermo-mechanical properties and oxygen vacancy diffusion remains incomplete. Based on free Helmholtz energy, we formulate analytical expressions to directly connect thermal expansion coefficient, elastic moduli, oxygen vacancy–dopant binding and oxygen vacancy migration energies by employing statistical moment method (SMM). The SMM calculations capture the full anharmonicity of lattice thermal vibrations. Our analyses report the significant influences of temperature and dopant content on the thermal expansion coefficient, bulk and Young's moduli, oxygen vacancy–dopant binding and oxygen vacancy migration energies, and ionic conductivity. The role of Pr dopant on the oxygen vacancy diffusion is fully described by combining the symmetric energy profiles related to blocking effect and asymmetric energy profiles generated from trapping effect. By switching van der Waals (vdW) forces on and off in the SMM calculations, we first show that the vdW forces cause a positive effect on the mechanical properties but reduce the thermal expansion and resist the oxygen vacancy diffusion. Our findings are discussed concerning the results from other calculations and experiments in the literature. The insights on the thermo-mechanical properties and oxygen vacancy diffusion for PDC crystal can be generalized and applied to other ceramic materials that are essential for solid state batteries. [ABSTRACT FROM AUTHOR]

Monazite, with its unique chemical composition and stable crystal structure, shows significant potential for immobilizing high-level radioactive waste. In this study, a series of monazite ceramics were synthesized to study the effect of entropy change on their structure and aqueous durability. The synthesized ceramics exhibit a monoclinic structure (P2 1 /n), with an average grain size below 80 nm. MCC-1 leaching tests reveal that the normalized leaching rate decreases over time but increases with higher entropy. The five-element high-entropy ceramics have an average leaching rate of 4.2 × 10⁻³ g·m⁻2 d⁻1. Notably, the higher leaching rate in high-entropy nanocrystalline monazites is likely attributed to the reduced grain size. The presence of numerous grain boundaries tends to mitigate the precipitation inhibition effect typically associated with high-entropy ceramics. These findings offer insights into the role of entropy and grain size in ceramic materials for radioactive waste immobilization. [ABSTRACT FROM AUTHOR]

In this study, ZrB 2 -SiC-ZrC (ZSZ) composite powders with molar ratios C/(B + Zr + Si) = 1.5, 1.9 and 2.4 were obtained by sol-gel method and boro/carbothermal reduction reaction. Meanwhile, the impact of heat treatment temperature (1100 °C–1600 °C) and holding time (1 h–2.5 h) on the resulting powders were studied. The results showed that the ZSZ powder precursors were first completely converted to ZrO 2 , SiO 2 , B 2 O 3 and pyrolytic carbon after heat treatment at 1200 °C under the optimized molar ratio (2.4) and holding time (2.5 h). Then, the transformed oxidation products and pyrolytic carbon were completely transformed into ZSZ composite powders after optimized heat treatment at 1500 °C. The synthesized ZSZ composite powders are characterized by the core-shell structure, in which ZSZ particles act as the inner core are encapsulated by the low-crystalline ZrB 2 phase as the outer shell to form a core shell structure. The ZSZ composite ceramic materials prepared using the core-shell structural powders have excellent ablative properties in the range of 2000 °C, with the mass and line ablation rate of −3.5 × 10−4 g/cm3 and 2.39 × 10−3 mm/s, respectively. [ABSTRACT FROM AUTHOR]

Low thermal conductivities and high thermal expansion coefficients are desirable for rare-earth zirconate thermal barrier coating materials. Introduction of cation doping and adjustment of the nonstoichiometry are efficient methods for enhancing the thermophysical characteristics of materials. Herein, the thermophysical properties of Yb3+-doped nonstoichiometric gadolinium zirconate ceramic materials were investigated using first-principles calculations and solid-state reaction techniques. As the Yb3+ content increases, additional cations enter the interstitial spaces (for excess Gd3+ gadolinium zirconate) and form vacancy defects (for excess Zr4+ gadolinium zirconate), which serve as phonon scattering centres to decrease the thermal conductivity. When Yb3+ is doped at the same concentration, gadolinium zirconate with excess Zr4+ exhibits a lower thermal conductivity. Specifically, Gd 1.875 Yb 0.25 Zr 2.125 O 7 shows the lowest minimum thermal conductivity of 1.133 W/(m⸱K) (according to the Clark model) and 1.241 W/(m⸱K) (according to the Cahill model). In addition, the experimental results also suggest that the optimal content of Yb3+ is 0.25 excess Zr4+ gadolinium zirconate, which has the lowest intrinsic thermal conductivity of 1.037 W/(m⸱K) at 1300 K. Moreover, the thermal expansion coefficient of the Yb3+-doped excess Gd3+ nonstoichiometric material is greater than that of the doped excess Zr4+ material, this is due to the greater electronegativity difference between Yb3+ and Zr4+ than that between Yb3+ and Gd3+ and the lower binding energy of Gd-O than that of Zr-O. The experimental results and the calculated results are in good agreement. The aim of this work is to enhance the thermophysical characteristics of gadolinium zirconate ceramics for use as thermal barrier coating materials. [ABSTRACT FROM AUTHOR]

Gadolinium gallium aluminum garnet doped with cerium (GGAG:Ce), a promising ceramic scintillator material, is being excessively explored for its high quality optical properties by the bandgap engineering with different Ga/Al ratio. In this study, GGAG:Ce powders were synthesized using a solvothermal method and sintered at 1300 °C to investigate the impact of the gallium-to-aluminum (Ga/Al) ratio on optical characteristics. The results revealed that a decrease in the Ga/Al ratio led to a decrease in particle size. This observation can be attributed to the different reactivity and growth kinetics of gallium and aluminum precursors during the solvothermal process. Perturbations from the optimized Ga/Al ratio of 1.5–1.77 and 1.27 resulted in substantially enhanced photoluminescence (PL) and radioluminescence (RL) spectra intensities. PL lifetime measurements of various Ga/Al ratio exhibit average PL lifetime between 48 and 57 ns. Specifically, the deviations to 1.77 and 1.27 ratios yielded approximately 125 % and 106 %, respectively, in observed luminescent measurements compared to other ratios. This enhancement in PL and RL intensity suggests that the Ga/Al ratio plays a critical role in modulating the optical properties of GGAG:Ce ceramic powders. The results of this study also highlight the importance of the Ga/Al ratio in tailoring the optical or luminescence characteristics of GGAG:Ce powders. [ABSTRACT FROM AUTHOR]

A CO 2 -stable, easily sintered proton-conducting oxide electrolytes based on solid solution Ba 7 In 6 Al 2– x Zn x O 19-0.5 x with hexagonal structure has been synthesized for the first time. Within the homogeneity region (0 ≤ x ≤ 0.10), there is an increase in unit cell parameters, cell volumes and free cell volumes. The addition of Zn2+ markedly improved the sinterability of the material. The relative density of the ceramics of the doped samples reached 95 % at lower sintering temperatures than the parent phase. The electrical conductivity was studied using electrochemical impedance spectroscopy. Upon doping the oxygen-ion conductivity increased by 0.25 orders of magnitude at 800 °C. Proton transport was predominant below 500 °C for a wet atmosphere (pH 2 O = 1.92·10−2 atm). The investigated phases Ba 7 In 6 Al 2– x Zn x O 19-0.5 x are capable of hydration and incorporate up to 1.45 mol H 2 O vs 0.41 mol H 2 O for the parent phase. The studied phases exhibit chemical resistance to CO 2 under heat treatment at 600 °C. It was shown that solid solution Ba 7 In 6 Al 2– x Zn x O 19-0.5 x is a promising electrolyte material for intermediate-temperature fuel cells. [Display omitted] • The Zn-doping in solid solution Ba 7 In 6 Al 2– x Zn x O 19-0.5 x markedly improved the sinterability of the material and well-sintered ceramics were obtained with relative density 95 %. • The water uptake increased with increasing Zn-concentration. • Ba 7 In 6 Al 2– x Zn x O 19-0.5 x phases were protonic conductors at T < 500 °C in wet air. • Ba 7 In 6 Al 2– x Zn x O 19-0.5 x phases exhibited chemical resistance to pure CO 2. [ABSTRACT FROM AUTHOR]

Ti doping can improve the interfacial wettability and bonding condition between ZTA ceramic and high chromium cast iron (HCCI), but the underlying mechanism is still unclear. Therefore, the effects of Ti doping on the interfacial characters between ZTA and HCCI were investigated by experiment and first-principles calculations. Results of XRD, SEM, and high-temperature drop test indicate the presence of Ti at the interface and its effect on the formation of interfacial diffusion layer to improve the interface wettability and bonding obviously. The heat of segregation and work of adhesion obtained by first-principle calculations shows that the improvement in interface wettability and bonding is due to the promotion of dopped Ti atoms on the diffusion of Fe, Al, and Zr elements, but not the diffusion of Ti itself. Further investigation from the electronic level reveals that the doped Ti changes the charge distribution and orbital hybridization, and thus makes the formation or enhancement of strong ionic bonds and covalent bonds at the interface, improving the bonding strength and wettability of interfaces in ZTA/HCCI. The findings of this research can offer new insights into the modification of ceramics and enlarge the application of advanced ceramic materials. [ABSTRACT FROM AUTHOR]

In order to solve the increasingly serious electromagnetic wave pollution, the preparation of high-performance electromagnetic wave absorbing (EWA) materials has been very urgent. High-entropy ceramics have a good prospect in the field of EWA materials due to the unique effect brought by its multi-component elements. Therefore, in this study, the composition of high-entropy ceramics was designed by utilizing the Goldschmid tolerance factor. Then the high-entropy perovskite Ba(Zn 0.2 Yb 0.2 Ta 0.2 Nb 0.2 V 0.2)O 3 ceramic (BZO) with high EWA performance was prepared by high-temperature solid-phase method. The EWA mechanism of the material was explored based on the phase composition, microstructure and electromagnetic parameters of the samples. Good impedance matching and better attenuation ability were obtained for BZO-1100 due to the crystallographic transition and interface increase. As a result, BZO-1100 achieves excellent EWA performance at a thickness of 2.12 mm, with a minimum reflection loss (RL min) of −54.09 dB and an effective absorption bandwidth (EAB) of 2.81 GHz in the X-band. In addition, the possibility of the practical application of the BZO high-entropy ceramics is verified by electric field distribution simulations and RCS simulations. This study provides a valuable reference for the design of high-performance high-entropy perovskite ceramic absorber materials. [Display omitted] [ABSTRACT FROM AUTHOR]

High-entropy ceramic materials are promising for creating functional ceramics for various purposes. The unique properties of such materials make it possible to create new thermal barrier coatings based on them. Reducing costs, time and simplifying the technology of synthesis of high-entropy ceramics is the subject of numerous studies. In this work, the synthesis of high-entropy ceramics (Y 0,2 Yb 0,2 Lu 0,2 Eu 0,2 Er 0,2) 3 Al 5 O 12 in a powerful beam of fast electrons was carried out for the first time. A powder mixture of initial oxides, placed in the volume of a massive copper cell, was exposed in air to a short-term exposure to a beam of powerful fast electrons with an energy of 2 MeV and a beam current of 12 mA. The speed of movement of the cuvette with the powder mixture under the beam was 1 cm/s. The total irradiation time was 10 s. During the irradiation process, at least 96 % of the mass of the powder mixture melted, resulting in the formation of highly porous ceramic formations in the form of droplets. X-ray phase analysis showed that the melt droplets are high-entropy ceramics (Y 0,2 Yb 0,2 Lu 0,2 Eu 0,2 Er 0,2) 3 Al 5 O 12. The powder product remaining in the cuvette and not participating in the formation of droplets contains phases of the original oxides and intermediate phases of synthesized high-entropy ceramics. Electron microscopy with EDS showed a uniform distribution of elements on the surface and in the volume of the formed ceramic droplets. [ABSTRACT FROM AUTHOR]

Donor-doped SrNb 2 O 6 -based materials are regarded as highly promising candidates for high-temperature thermoelectric applications. The Sr 0.6 La 0.4 Nb 2 O 6-δ /x wt% Ti (x = 1, 5, 10, 15) composite ceramics thermoelectric materials were prepared and the mechanism for enhancing their thermoelectric properties was investigated. The experimental results demonstrate that during sintering, nano-additive titanium powder undergoes oxidation to form TiO 2. The inclusion of a secondary phase ultimately leads to successful reduction in electrical resistivity within the composite oxides. Due to crystal defects, complex structure and phonon scattering at grain boundaries, the samples consistently exhibit low thermal conductivity values below 3.0 W m−1K−1. Among them, the sample doped with 10 wt% Ti shows the highest PF value (470.0 μW/mK2 at 1073 K), demonstrating a significant increase in power factor of 280 % compared to Sr 0.6 La 0.4 Nb 2 O 6 without the Ti composite. Consequently, the Sr 0.6 La 0.4 Nb 2 O 6-δ /10 wt% Ti composite material achieved a maximum ZT value of 0.20, representing a fifty-three percent enhancement compared to the undoped sample. [ABSTRACT FROM AUTHOR]

Rare earth ions doped ferroelectric ceramics have attracted much attention because rare earth ions can effectively regulate the ferroelectric and energy storage properties of ceramics. Herein, Ba 1- x Ca x Ti 1- y Hf y O 3 ceramics modified with Ca2+ and Hf4+ are prepared, and the effects of different Ca2+ and Hf4+ concentrations on the crystal structure, microstructure and electrical properties of Ba 1- x Ca x Ti 1- y Hf y O 3 ceramics are investigated. Through the analysis on the ceramic structure and electrical properties, Ba 0.96 Ca 0.04 Ti 0.85 Hf 0.15 O 3 (BCTH) ceramic shows excellent comprehensive performance. Using BCTH ceramic as matrix material, the influences of different Pr3+ concentrations on the structure and electrical properties of the BCTH: x %Pr3+ ceramics are studied. Energy storage efficiency (η) gradually increases with the increase of Pr3+ concentration, while the energy storage density (W d) shows a trend of first increasing and then decreasing, reaching the maximum value for x = 0.6 (W d = 0.338 J/cm3, η = 87.86 %), which was higher than that of pure BCTH ceramics (W d = 0.212 J/cm3, η = 78.05 %) increased by 59.43 % and 12.57 %, respectively. All the samples show good stability of energy storage temperature and frequency. After Pr3+ doping, the Curie transition temperature of the ceramics first increas and then decreases, and show a wider transition peak, indicating that the transition from ferroelectrics to relaxation ferroelectrics occurres. The excellent electrical properties of BCTH: x %Pr3+ ceramics indicate their potential application value in the field of electricity. [ABSTRACT FROM AUTHOR]

With the development of the electronic packaging industry, there is an increased demand for enhanced strength in DBA substrates. Ultrasonic soldering technology allows low-temperature joining of ceramic-metal materials under ambient air conditions. In this paper, we successfully achieved the joining between AlN ceramics and 2024Al using Sn9Zn solder and ultrasonic soldering technique, while also analyzing the joining mechanism through Comsol software simulations. It was observed that under the appropriate ultrasonic amplitude and frequency, the Sn9Zn solder exhibited complete wetting with both base materials, resulting in reliable joints. Building upon this finding, the conventional Sn9Zn solder was further optimized by adding Sb element. The addition of Sb element led to the formation of Zn 4 Sb 3 phase and β-Sn(Sb) phase with Sb acting as solute. Among them, the generation of β-Sn(Sb) solid solution phase effectively improved the joint strength. The maximum joint strength was achieved at an average value of 75.066 MPa when the Sb content reached 1 wt. %. At this point, the failure occurred within the AlN ceramic base material. [ABSTRACT FROM AUTHOR]

SiC whiskers (SiC w)-reinforced α/β-SiAlON ceramic tool materials were synthesized via spark plasma sintering (SPS). A comprehensive study was conducted on densification mechanism, phase composition, microstructure, mechanical properties, and wear resistance of the SiC w /α/β-SiAlON composites. The results indicated that SiC w constrained the densification process and impeded the growth of SiAlON grains, and the introduction of SiC w significantly enhanced mechanical properties of the α/β-SiAlON ceramic. The composite containing 28 wt% SiC w synthesized at 1700 °C showed well mechanical properties, with a density of 3.35 g/cm³, Vickers hardness of 19.38 ± 0.33 GPa, and fracture toughness of 7.35 ± 0.27 MPa m1/2.The principal toughening mechanisms of SiC w /α/β-SiAlON included crack deflection, branching, bridging, as well as transgranular fracture and whisker pullout. The addition of SiC w improved the wear resistance of α/β-SiAlON ceramic. Compared to those without whiskers, the wear volume and wear rate were decreased by 38.8 %. [ABSTRACT FROM AUTHOR]

Fluorapatite glass-ceramic (GC) and yttria-stabilized zirconia (YSZ) are two commonly used ceramic materials for dental prosthetic restorations. Fluorapatite GCs are known for their outstanding biocompatibility and aesthetic characteristics, moreover, they can release fluoride ions which have anticaries effect. Nevertheless, they often lack the requisite strength and toughness to withstand high occlusal forces. Conversely, YSZ exhibits remarkable mechanical properties, however, it is susceptible to excessive wear on opposing teeth. To address these limitations, a novel fluorapatite GC-YSZ composite ceramic was designed and formed through vat photopolymerization. The effect of composition ratios of fluorapatite GC particles and YSZ fibers (0˗40 wt% YSZ) on the forming precision, mechanical properties, and tribological compatibility with GC was thoroughly investigated. The results demonstrated that optimal comprehensive performance was achieved when the YSZ fiber content reached 40 wt%, which resulted in a fracture toughness of 1.68 MPa m1/2, marking a 98.8 % increase over pure GC. The specific wear rates of the sample and the antagonistic titanium ball were reduced by 75.6 % and 63.8 %, respectively, compared with GC. In addition, the dimensional accuracy error of the green body was reduced by approximately 44 %. The design and fabrication of GC-YSZ composites offer an approach for developing high-performance all-ceramic dental materials. [ABSTRACT FROM AUTHOR]

Highly robust ceramics materials are promising materials for applications in the automobile, aerospace, and ceramic cutting tool industries. However, conventional ceramics are typically brittle, which limits their suitability for advanced applications. In this study, with zeolite imidazolium salt skeleton-8 (ZIF-8) as a carbon source, discharge plasma sintering is used to create carbon nanonetworks derived from metal-organic frameworks (MOFs) in situ on the grain boundaries of zirconia-toughened alumina (ZTA) ceramic. ZTA exhibits maximum bending strength (719 ± 20.5 MPa) and fracture toughness (7.91 ± 0.7 MPa m1/2) at MOF concentrations of 1.0 wt% and 2.0 wt%, respectively, which are 1.37 and 1.88 times higher than that of the unmodified sample. This demonstrates that the MOF-derived carbon nanonetworks significantly improve the mechanical properties of the ceramic. The finite element analysis results indicate that the carbon nanonetworks can effectively disperse the stress inside the material and transfer the concentrated stress from the internal defects to the two-phase grain boundary on the surface of the sample, thereby contributing to strengthening and toughening. Overall, this work validates that the in situ production of carbon nanonetworks from MOFs is an effective strategy to enhance the mechanical properties of ZTA ceramics. Moreover, it offers new approaches for reinforcing and toughening other ceramic materials. [ABSTRACT FROM AUTHOR]

The social progress, economic growth, and meteoric urbanization prompt the exploitation of available resources triggering the contagion of the biological and physical elements of the atmosphere irrationally causing global environmental pollution. Environmental contamination monitoring is a dire necessity. Although a number of technologies find mention in the literature for environmental remediation, however, environmental catalysis is an advanced steadily growing technique for pollution abatement. In this dimension, ceramic materials have turned heads due to their wide‐scale application areas. Hitherto, research is being done on advanced ceramics to fabricate novel modules for energy storage applications, in designing green buildings, pollution rheostats, and environmental engineering. This article deals with the abatement of environmental contaminants by adopting various methodologies such as aerobic and anaerobic biological treatments, adsorption, chemical oxidation, membrane separation, photocatalysis, ozonation using the ceramic as precursor materials. The ceramic membranes are cost‐effective, ecofriendly, efficacious, and green approach to obliterate toxins and harmful gases released in environment. Even though, limited literature is available on the abolition of harmful contaminants from air and soil using ceramic materials, an attempt has been made to present currently available data with best of our knowledge. This article will sensitize researchers to refabricate novel materials for environment sustainability. [ABSTRACT FROM AUTHOR]

The thermal shock resistance of ceramics is a key factor for determining the durability of ceramic components under transient thermal conditions and is also one of the key factors for evaluating the stability of ceramics under extreme thermal conditions. After rapid heating or cooling, the surface and internal thermal stress mismatches of ceramics can cause severe thermal damage. Two main types of ceramic thermal shock exist: rapid cooling and rapid heating thermal shock. This article presents a broad understanding and insight into fundamental theory and experimental methods for ceramic thermal shock testing. The experimental equipment and procedures, test result evaluation, and material characterization of ceramic thermal shock are summarized. Moreover, outlooks and perspectives are discussed for testing and characterizing ceramic thermal shock resistance. This review will be helpful to researchers performing studies in the relevant fields of ceramics. [ABSTRACT FROM AUTHOR]

Dysprosium (Dy)‐doped (Y1−xDyx)3Si2C2 (x = 0, 0.1, 0.3, 0.5) solid solution ceramics were successfully fabricated using an in situ reaction spark plasma sintering technology, for the first time. The effect of various Dy doping contents (x) on the microstructure, mechanical, and thermal properties of (Y1−xDyx)3Si2C2 ceramics was investigated. The (0 2 0) crystal plane spacing of (Y0.5Dy0.5)3Si2C2 was 7.813 Å, which was smaller than that of Y3Si2C2, due to the fact that the atomic radius of Dy is smaller than that of Y. The Dy doping facilitated the consolidation of (Y1−xDyx)3Si2C2, thus a highly dense (Y0.5Dy0.5)3Si2C2 ceramic material with a low open porosity of 0.14% was successfully obtained at a relatively low temperature of 1 200°C. As the content of Dy doping (x) increased from 0 to 0.5, the purity of (Y1−xDyx)3Si2C2 ceramics increased from 88.3 to 90.7 wt.%, while the grain size of (Y1−xDyx)3Si2C2 ceramics decreased from 0.59 to 0.46 µm. As a result, the Vickers hardness and thermal conductivity of the (Y0.5Dy0.5)3Si2C2 material was 7.1 GPa and 9.8 W·m−1·K−1, respectively. [ABSTRACT FROM AUTHOR]

Knowledge about the thermodynamic equilibria of the Al 2 O 3 –TiO 2 –CaO system is important for the design of refractory and ceramic materials. The Al 2 O 3 –TiO 2 , Al 2 O 3 –CaO and CaO–TiO 2 binary systems were reoptimized and the Al 2 O 3 –TiO 2 –CaO ternary system was assessed by CALPHAD (CAlculation of PHAse Diagram) approach due to the reliability of phase diagram and thermodynamic property data. The liquid phase was described by the ionic two-sublattice model with the formula (Al+3,Ti+2,Ti+3,Ca+2) P (O−2,AlO 1.5 ,Va,O,TiO 2) Q. A set of self-consistent thermodynamic parameters for the Al 2 O 3 –TiO 2 –CaO ternary system was finally obtained, reproducing well the phase diagram and thermodynamic properties, predicting the Ca 4 Ti 3 O 10 primary crystallization field. The present thermodynamic description is of interest for the design of refractory and ceramic materials as well as the development of thermodynamic databases for multicomponent aluminosilicate system. [ABSTRACT FROM AUTHOR]

Synthesis of porous ceramic materials based on fine SiC with sintering silicon oxide and magnesia binders at T = 800–1300 °C is considered. Special attention is paid to the influence of the shape and morphology of the initial powder particles on structural parameters and characteristics of porous ceramic materials. The SiC membranes sintered at 1000–1300 °C had average pore sizes of 0.5–1 μm, open porosity - up to 50 %, bending strength - up to 48.5 MPa and high water permeance - up to 7890 l⋅m−2⋅h−1⋅bar−1. The established filtration efficiency was ∼99 % in the case of screening out model particles of D 50 = 0.5 μm in size with maintaining stable permeance and physico-mechanical characteristics after multiple filtration-regeneration cycles. Comprehension of the initial powders morphology impact on the synthesized porous ceramics parameters makes it possible to forecast and ensure the preset structural, dimensional and physico-mechanical parameters of the materials under study properly. This work can be used for practical low-cost production of highly efficient SiC membranes for micro- and ultrafiltration processes, as well as base for catalysts. [ABSTRACT FROM AUTHOR]

Ceramic materials with excellent radiation resistance stability play an indispensable role in the treatment of nuclear waste. This article uses spark plasma sintering (SPS) to synthesize high-entropy (HE) Y 0.6 Gd 0.6 Sm 0.6 Eu 0.6 Dy 0. 6 Fe 5 O 12 (HEG) and traditional garnet Y 1.2 Nd 1.8 Fe 5 O 12 (YIG). Studied the effects of 2 MeV He2+ irradiation (1 × 1014 ions/cm2 - 1 × 1017 ions/cm2) on the crystal structure, mechanical properties, and chemical stability of ceramics. Research shows that the surface of YIG becomes completely amorphous under ∼30dpa irradiation. Under irradiation at∼30dpa, HEG underwent a small amount of amorphization (with an amorphization rate of 38 %), maintaining the structure of garnet, and the lattice expansion rate of HEG caused by irradiation was lower than that of YIG. After irradiation, the mechanical properties of HEG were improved, while YIG's hardness decreased due to its amorphous state. Radiation has almost no effect on the chemical stability of HEG, and its long-term release mechanism is dominated by diffusion. This study identified HEG as an ideal candidate substrate for immobilizing high-radioactive waste (HLW) the perspective of radiation resistance. [ABSTRACT FROM AUTHOR]

In sophisticated engineering machining, ceramic materials are in great demand in today's precision industries because they have a wide range of potential applications, including automobiles, aircraft, and biomedical engineering. Silicon nitride ceramics (Si3N4) are difficult to manufacture using conventional machining processes. Modern technology allows Ultrasonic Micro-machining (USMM) to create almost any kind of material. Abrasive particles made of silicon carbide are used in this research work to look into the Si3N4 USMM process parameters. The physical structure and chemical composition have been examined in a scanning electron microscope with an integrated energy-dispersive X-ray analyzer. Particle swam optimization and Response Surface Methodology (RSM) desirability were the two types of optimizations used to find the best USMM process parameters. It has been shown that both techniques can be used together to get the best Material Removal Rate (MRR). The best settings were Slurry Concentration: 50 (g/l), Power Rating: 329 (W), and Tool Feed Rate: 1.06 (mm/min). Similarly, to minimize Overcut (OC) and Taper Angle (TA), the ideal method is to use a slurry concentration of 50 (g/l), a power rating of 400 (W), and a tool feed rate of 1.2 (mm/min). Finally, using the RSM, the USMM process was optimized in a way that maximized the MRR while minimizing OC and TA. It was found that the slurry concentration of 42.7 g/l, the power rating of 357.6 W, and the tool feed rate of 1.2 mm/min were the ideal settings for the USMM process. [ABSTRACT FROM AUTHOR]

Carbon fiber-reinforced ceramic matrix composites have excellent heat resistance and wear resistance, making them extensively utilized in the aviation and aerospace industries. However, processing carbon ceramics is challenging due to the inherent difficulty. Traditional hole-making methods often result in issues such as delamination and tearing during the processing of carbon ceramics. Helical grinding has emerged as a novel processing technology that shows promise for difficult materials like carbon ceramics. To address the lack of clarity regarding the removal mechanism and formation mechanism of material damage during helical grinding of carbon ceramic materials, firstly, this study models the trajectory and maximum undeformed chip thickness for a single abrasive. Subsequently, this study analyzes the influence of fiber anisotropy on the removal mechanism during helical grinding of carbon ceramics. The study also investigates the mechanisms behind exit damage occurring during carbon ceramic helical grinding processes. Finally, this study examines helical grinding technological parameters that affect surface quality by analyzing their impact on undeformed chip thickness. The results indicate that the matrix occurs brittle fracture during helical grinding. Four typical removal mechanisms emerge for different fiber angles: debonding is predominant at 0°; fiber fracture occurs at 45°; fiber shear occurs at 90°; fiber pull-out occurs at 135°. Hole exit damage is influenced by fiber direction with minimal damage observed when shear fracture occurs at angles 45° and 90° while burrs phenomenon and tear phenomenon are prevalent at angles 0°and 135°, respectively. By increasing orbital rotation speed and spindle speed or decreasing feed pitch, surface quality improved. Grinding parameters significantly affect surface quality by changing undeformed chip thickness and surface residual height. [ABSTRACT FROM AUTHOR]

Barium zirconate doped with 20 mol% Yb (BaZr 0.8 Yb 0.2 O 3-δ , BZYb20) is one of the most promising candidates for use as an electrolyte material in protonic ceramic fuel cells (PCFCs) due to its high proton conductivity and high chemical stability under CO 2 -containing fuel conditions. The long-term durabilities of PCFCs prepared using the BZYb20 electrolyte were evaluated as a function of the current density at 500 and 600 °C over a period of 1000 h. At 600 °C, the internal resistance of the cell increased even under open circuit voltage (OCV) condition. Comparing the voltage lowering rates at a current density of 0.172 A cm−2 based on the current density–voltage curves recorded during the durability tests, rates of 3.0, 5.3, and 9.0%/1000 h were achieved at the OCV, 0.047, and 0.172 A cm−2, respectively. A small amount of Ni elements diffused into the electrolyte from the anode to the cathode side, resulting in the formation of cumulus cloud shapes that corresponded to Ni element segregation at the grain boundaries in the electrolyte layer after long-term durability testing at 0.172 A cm−2. At current densities of 0.047–0.048 A cm−2, the voltage lowering rate at 500 °C was higher than that at 600 °C, with values of 6.0 and 2.6%/1000 h being recorded, respectively. This effect may be due to the higher resistance of the cell at 500 °C compared to that at 600 °C. [ABSTRACT FROM AUTHOR]

The search for novel functional ceramic materials with targeted properties is currently very important. Complex oxides with perovskite or perovskite-related structure are being considered for the production of electrochemical devices for the hydrogen energy ecosystem. Layered perovskites including based on BaLaInO 4 are promising materials for proton-conducting electrolyte of solid oxide fuel cells. The idea of this work is to create a triple conductivity material based on BaLaInO 4. In this work, the doping of the lanthanum sublattice with iron ions was carried out for the first time. The effect of doping on the structure, water uptake and electrical conductivity was investigated. It was shown that the introduction of iron ions into lanthanum sublattice changes the crystal lattice from orthorhombic to tetragonal structure. The water uptake is very small and it is 0.02 mol H 2 O per formula unit for BaLa 0.9 Fe 0.1 InO 4–δ composition. Studies of the electrical properties have shown that the nature of conductivity is mixed hole/oxygen ionic at dry air and hole/oxygen ionic/protonic and wet air. The Fe-doped-composition can be considered as triple conducting materials and it is prospective as the electrode materials comparable with protonic electrolyte Ba 1.1 La 0.9 InO 3.95. [ABSTRACT FROM AUTHOR]

The search for new promising ceramic materials for various applications is an important task. In particular, ceramic materials are required as a part of electrochemical energy devices such as solid oxide fuel cells. Layered perovskites are promising materials for proton-conducting electrolyte of solid oxide fuel cells. In this article, samarium doped composition BaLa 0.9 Sm 0.1 InO 4 was obtained for the first time. The effect of doping on the structure, water uptake and ionic transport (O2− and H+) was investigated. It was shown that the samarium doping leads to the increase in conductivity values of up to 2 orders of magnitude. At low temperatures the proton transport numbers are 87–93 %, which indicates dominance of proton transfer. [Display omitted] [ABSTRACT FROM AUTHOR]

The disposal of electric arc furnace (EAF) slag is often problematic, with most of it ending up being landfilled rather than recycled. Incorporating EAF slag into the typical clay-feldspar-quartz system to produce useful ceramics offers a potential and environmentally safer option. Thermodynamics package FactSage 8.2 was employed to predict the equilibrium-products of sintering process of EAF slag mixtures at different temperatures ranging from 600 to 1600 °C. Subsequent ceramic products were fabricated at a temperature of 1150 °C following the thermodynamic analysis by considering the fraction of liquid formation and the viscosity of the system. These products were further subjected to X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses and compared to the thermodynamic predictions. The physical performance of the products was also examined by evaluating the shrinkage, water absorption, apparent porosity, bulk density and modulus of rupture (MOR). When EAF slag was added to the base mixture, there was a positive trend of improvement in the physical properties and specifically, MOR peak value of 37.56 MPa was obtained when 40 % EAF slag was added. However, the MOR value as well as other physical properties started to decline when the base mixture had more than 40 % EAF slag. Conclusively, incorporating 40 % EAF slag improved the final product and correlated with the thermodynamic studies, process parameters, and experimental assessments of the ceramic tiles. [ABSTRACT FROM AUTHOR]

High-performance Ox-Ox ceramics material composites (CMC) are a strategic building block in the aerospace industry and high-temperature applications. The ceramics material composites are hard to machine due to high hardness, fracture toughness, and heterogeneous structures. Furthermore, it is prone to brittle fracture during the machining process. In this study, we successfully demonstrate ultrafast laser machining technology to machine Ox-Ox CMCs. A picosecond laser has been used to machine slots to understand the impact of laser process parameters on the material removal mechanism by performing deep machining. Different scan rates and a number of over-scans have been employed to understand the material removal mechanism, which is dominated by laser ablation and aided by melting due to the residual surface temperature. The maximum material removal rate of 21.75 mm3/min has been achieved for the scan rate of 300 mm/s. This can be related to the reduction in the ablation threshold and the critical balance between the material removal mechanism by ablation and melting. It was found that, the surface roughness of the cut surface has decreased due to melting and solidification. The cross-sectional examination reveals two distinct surface structures, which are entirely resolidified and thermally eroded regions. [ABSTRACT FROM AUTHOR]

High-entropy dielectric capacitors have recently drawn increasing attention in the field of energy storage. In this study, NiO has been incorporated into [(Na 0.7 Bi 0.1) 0.8 Sm 0.02 Ca 0.02 Sr 0.02 Ba 0.02 ]Nb 0.8 Sb 0.1 Ta 0.1 O 3 -based ceramics. We applied the concept of high-entropy design to introduce cation vacancies at the A-site, enhancing conformational entropy. This approach led to the successful preparation of a novel type of energy-storage ceramics with an ABO 3 perovskite structure, denoted as (1- x)NBSCSBNST- x NiO (x = 0, 0.02, 0.04, & 0.06). We conducted a systematic study of the microstructural, dielectric, and ferroelectric characteristics, along with an exploration of the influence of the high-entropy strategy on their performance. The Δ S config increases with NiO doping, and the E b of the NBSCSBNST-0.02Ni sample exhibits a significant increase to 730 kV/cm from 550 kV/cm of NBSCSBNSTN. This enhancement is accompanied by a recoverable energy density (W rec) of 4.43 J/cm3 and an efficiency (η) of 75.9 %. As the content of NiO increases from x = 0 to x = 0.06, the phase transition diffusion behavior strengthens. Additionally, the permittivity (ε r) spectrum becomes more uniform, and the activation energy of the prepared ceramic samples increases from 1.03 eV to 1.76 eV. This effect suppresses the emergence of localized electric branching, eventually improving the breakdown strength of NBSCSBNST- x Ni ceramic materials. The obtained results indicate that the concept of high-entropy design to introduce cation vacancies at the A-site is an efficient approach to improve the energy storage characteristics of lead-free dielectric capacitors. [ABSTRACT FROM AUTHOR]

Al 2 O 3 -based ceramic tool materials synergistically reinforced by SiC whiskers (SiC w) and SiC particles (SiC p) were prepared via spark plasma sintering (SPS) technique. The densification behavior, sintering kinetics and optimal ratios of SiC w and SiC p on Al 2 O 3 -based ceramic tool materials were investigated. Results indicated that densification mainly occurred from 1200 to 1450 °C. Grain boundary sliding or grain boundary diffusion was the primary cause of densification at 1200–1350 °C. Whereas, dislocation climbing was the main densification mechanism at 1400–1450 °C. W25P5 sintered at 1450 °C had a large relative density, small grain size and the best mechanical properties with the fracture toughness of 7.35 ± 0.19 MPa m1/2, Vickers hardness of 21.79 ± 0.21 GPa, and relative density of 98.86 ± 0.15 %. The synergistic toughening mechanisms included crack deflection, whisker bridging and whisker pull-out. [ABSTRACT FROM AUTHOR]

Cubic phase Li 7 La 3 Zr 2 O 12 (LLZO) is a promising electrolyte material for all-solid-state rechargeable lithium-ion batteries. The homogeneous densification of the garnet solid electrolyte ceramic material is crucial for enhancing its ionic conductivity performance. Herein, an Al/Ta co-doped strategy is employed to stabilize the cubic phase structure of LLZO and is combined with a two-step sintering method to enhance densification, in order to investigate its effect on microstructure, ionic conductivity, and electrochemical properties. During the formation process, amorphous Li 2 O reacts with doped Al 2 O 3 to create a Li–Al–O liquid phase at the grain boundaries. Combined with two-step sintering to ensure that the desired material transformation is achieved, resulting in a dense microstructure and better mechanical properties. The solid electrolyte Li 6.4 Al 0.1 La 3 Zr 1.7 Ta 0.3 O 12 under two-step sintering (LLZATO-2) is successfully synthesized, delivering an ionic conductivity up to 7.33 × 10−4 S cm−1 at room temperature and an activation energy of 0.22 eV. This work also highlights the critical role of co-doping combined with two-step sintering in preparing well-performing solid-state electrolytes and all-solid-state lithium-ion batteries. LLZO solid electrolyte with lithium ion conductivity is prepared by Al/Ta co-doped combined with two-step sintering. The experimental and theoretical results indicate that amorphous Li 2 O reacts with Al 2 O 3 to form a Li–Al–O liquid phase at the grain boundaries, filling the pores generated at the grain boundaries. The two-step sintering further suppresses grain growth and promotes densification growth. [Display omitted] [ABSTRACT FROM AUTHOR]

Successful upscaling of tungsten fiber‐reinforced tungsten composites (Wf/W) on industrial level could represent an important milestone for future nuclear fusion reactors. The primary objective of these materials is to enhance the durability and operational lifespans of critical components. Developing mature manufacturing approaches remains a challenge, highlighting the need for innovative solutions. This study evaluates the feasibility of merging chemical vapor deposition (CVD) with spark plasma sintering (SPS) for producing such composites. This analysis indicates that combining CVD‐W sealed tungsten fabrics with SPS requires additional manufacturing steps or the utilization of tungsten powders for effective sintering. The process is currently only suitable for simple textile structures utilizing single filaments, mitigating one of the main advantages of CVD. Configurations such as radially braided yarns are currently less compatible to the high stress levels during SPS. A key outcome of this work is the introduction of a thin secondary CVD‐W interface into the composite design, substantially improving the stability of the yttria‐interface and effectively shielding the W‐fibers from potential matrix interactions. This innovation reduces issues such as carbon embrittlement and allows the potential integration of tungsten fibers into different matrix materials such as ceramics, broadening the potential application range of tungsten fiber‐reinforcements. [ABSTRACT FROM AUTHOR]

High‐entropy perovskite ceramics have garnered widespread attention in the energy storage field due to their diversified composition and superior performance. However, the preparation of high‐performance high‐entropy ceramic materials still faces many challenges due to their complex composition and structure. This work systematically studies the effects of MgO, SiO2, Li2CO3, and MnCO3 on the sintering temperature and energy storage performance of (Na0.2Bi0.2Ba0.2Sr0.2Ca0.2)TiO3 (NBBSCT) high‐entropy ceramics. The introduction of MnCO3 successfully reduced the sintering temperature of the high‐entropy ceramics to 1150°C and achieved a high energy storage efficiency of 95.5% with this composition. The NBBSCT ceramics with 0.5 wt%MgO exhibited a breakdown field of 300 kV/cm and an energy storage density of 3.7 J/cm3. The study indicates that adding appropriate sintering aids can significantly improve the sintering behavior and energy storage performance of high‐entropy ceramics. This method provides new insights into the preparation and performance enhancement of high‐entropy energy storage ceramics. [ABSTRACT FROM AUTHOR]

Porous mullite ceramics were synthesized via ceramic processing using a local industrial kaolin, alumina, and with AlF3 and MoO3 precursor additives to catalyze the formation of pores and acicular mullite grains. The textural properties, crystalline phases, microstructures, and mechanical properties of the obtained samples were comprehensively analyzed and compared with a reference mullite formulated without additives. The obtained ceramics have a well‐defined porous microstructure, with a porosity of about 50%, and a pore size distribution in the 0.1–2 µm range. Ceramics that involve the addition of MoO3 present well‐defined acicular mullite grains, with slightly higher porosity, larger pores, and better mechanical resistance compared to those processed using AlF3.To correlate the ceramic porosity with its mechanical properties, a simple model of spherical pores was proposed to assess the flexural strength of the dense ceramic. It was found that the inclusion of additives promoting needle‐like microstructures increases the mechanical resistance up to four times the value determined for the ceramic without additives (flexural strength up to 390 MPa for zero‐porosity extrapolation). These results, together with the refractoriness of mullite, allow inferring the potential applications of the developed materials as structural ceramics with relatively low density and for filtering applications. [ABSTRACT FROM AUTHOR]

Mosaic ceramics are not limited to use solely as building materials, they also possess artistic value. Artists can create images by arranging and combining mosaic ceramics, resulting in a perfect fusion of large-scale public art for external walls and ceramic materials. However, the current approach for artists to create mosaic ceramic exterior wall art images involves manual laying and assembling of individual mosaic ceramics. This manual process suffers from issues such as low efficiency, eye fatigue, selection errors, and the risk of high-altitude operations. These challenges significantly impact the quality and efficiency of creating mosaic ceramic exterior wall art image images. To address these problems, this paper proposes an automatic mosaic ceramic art image stitching method based on subpixel edge fitting positioning and collaborative operation of multiple robotic arms. Additionally, a new U + I type conveying method is designed for efficient and space-saving transportation of mosaic ceramics. Experimental results demonstrate a high success rate of recognition, absorption, and placement of multi-color mosaic ceramics using this method reaching 95.45%, with a positioning error within 0.5 mm. The method can also adapt to varying levels of light intensity or noise interference. This approach effectively enhances the quality and efficiency of creating mosaic ceramic exterior wall art images and promotes the development of mosaic ceramic exterior wall public art creation. [ABSTRACT FROM AUTHOR]

We have successfully fabricated a series of the SmCaBCuO bulk superconducting ceramics with different ratios of nanoscale Boron doping into mixture powder by the solid-state reaction method. Permanent magnets (PMs) with three different values in the same form were used for magnetic levitation force (MLF) measurements. During measurement of levitation forces between small PMs and bulk high Tc superconducting ceramic materials, significant hysteretic behavior was observed as a function of the distance between the magnet and the superconductor. We focused on the effect of doping and different permanent magnets on magnetic levitation force (MLF) measurements and magnetic stiffness calculations of materials, considering zero field-cooling (ZFC) and field-cooling (FC) conditions. It was seen that MLF decreased with the increase in boron dopant in the sample under ZFC conditions. We explained this result with weak bonds between grain boundaries, cracks and grain size reduction in the samples. Under FC conditions, with the increase of permanent magnet value and nano boron doping, the levitation force, which should be effective, left its place to the attractive force. Flux trapping centers formed by doping dominate the attractive force. The increase in doping caused a decrease in magnetic stiffness values. The increase in the permanent magnet caused an increase in the stiffness values of the material. This result agrees with the literature. The MLF and magnetic stiffness data got will be useful in the technological applications of maglev and carrier systems. [ABSTRACT FROM AUTHOR]