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Waste management and recycling have led to numerous studies on particleboard production. This study attempted to use milled corncob (MCC) and waste ceramic tiles (WCTs) to produce particleboard. The MCC (100−70 wt.%) and WCT (0–30 wt.%) were mixed at different ratios, mixed and compressed at a pressure of 0.25 MPa using urea formaldehyde (UF) resin as adhesive. The physicomechanical and thermal properties of the particleboards produced were investigated. The physical properties (bulk density, water absorption, and thickness swelling) improved with composite particleboard compared to the 100% MCC particleboard. The increase in WCT yielded improved density and lowered the particleboard's water absorption and thickness swelling. The mechanical tests showed that MOE values were below the recommended standard, which makes them unsuitable for structural use. However, MOR revealed values above the recommended standard. The thermal conductivity of the particleboards was reduced with increased WCT, and the required standard was found to be met. Hence, the particleboards produced are found helpful as thermal wall insulators. Based on the experiments done, sample R7 (70% MCC and 30% WCT) was considered the most preferable since it achieved the most preferable physicomechanical and thermal conductivity performance. The particleboards produced are recommended for wall partitioning and other internal and external purposes. [ABSTRACT FROM AUTHOR]

h-BN is a two-dimensional ceramic material with a lamellar structure, known for its typical orientation characteristics on mechanical and thermal properties. By optimizing the size and arrangement of h-BN grains in the matrix, the anisotropic characteristics of h-BN ceramics can be fully utilized to obtain ceramic materials with high thermal conductivity or high strength. In order to study the effect of grain orientation distribution on the mechanical and thermal properties of materials, the index of orientation distribution (IOP) was used to quantitatively characterize the orientation degree of h-BN grains and analyzed the effect of h-BN grain size on material properties. The results show when the initial h-BN size is 13.50 μm, the ceramic has the highest orientation degree/-507, and the mechanical and thermal properties show obvious anisotropy. While the related properties of BN-YAG ceramics varies significantly with the decrease of initial h-BN grain size. [ABSTRACT FROM AUTHOR]

Hybridization of natural fibers with ceramic materials for reinforcing composites allows the optimization of the properties of these materials. For this reason, the present study aims to investigate physical, mechanical, water absorption, swelling and thermal properties as well as morphological characteristics of a hybrid Paederia foetida fibers–alumina powder (PFs–Al2O3)‐reinforced epoxy composite. Epoxy resin served as the matrix, while PFs and Al2O3 were employed as reinforcement. Five types of composites were fabricated using the hot‐pressing technique. The corresponding ratios of PFs:Al2O3 volume fractions (%) considered here were 0:40 (SFA), 10:30 (SFB), 20:20 (SFC), 30:10 (SFD) and 40:0 (SFE). The results reveal that the density of the hybrid PFs–Al2O3 composites decreased for increasing volume fractions of PFs: from 2.173 g cm−3 of SFA to 1.042 g cm−3 of SFE. The highest values of tensile strength (i.e. 49.085 MPa), tensile elastic modulus (i.e. 1.431 GPa) and impact strength (24 kJ m−2) were obtained for the SFD composite material with 30% volume fraction of PFs and 10% volume fraction of Al2O3: this happened because interface bonds between PFs, Al2O3 and epoxy phases achieved their optimal configuration. Overall, mechanical properties of the hybrid PFs–Al2O3‐reinforced epoxy composites were superior to those of composites reinforced only by PF fibers or only by Al2O3. Water absorption and swellability reached their maximum values at the steady state occurring after tested samples remained immersed in water for 820 h. The SFE composite reinforced only by PFs presented the highest water absorption and swelling (i.e. 6.034% and 5.81%, respectively) while for all other hybrid composites (SFD, SFC and SFB) these two quantities remained below 5%. Density and volume fraction of voids of hybrid PFs–Al2O3‐reinforced composites were consistent with the corresponding properties of the composites reinforced only by Al2O3 or PFs. SFD was also the most thermally stable material. Scanning electron microscopy observations of fractured surfaces indicated that the microstructure of the PFs–Al2O3‐reinforced epoxy composites presents several voids, fiber pullouts and transverse fibers, which together optimize the mechanical response of the composite material. Remarkably, the SFD composite material was highly competitive with the most recently developed hybrid composites employing natural reinforcements. © 2024 Society of Industrial Chemistry. [ABSTRACT FROM AUTHOR]

The high-entropy ceramic materials (Zr 0.25 Ce 0.25 Hf 0.25 Y 0.25)O 1.875 (H-0) and (Zr 0.2 Ce 0.2 Hf 0.2 Y 0.2 RE 0.2)O 1.8 (H-RE) (RE = La, Nd and Sm) with fluorite structure and homogeneous element distribution were prepared. With fluorite structure, fine grain size and high density, the H-0 and H-RE ceramics displayed low thermal conductivity, suitable thermal expansion coefficient, high hardness and fracture toughness. The effect of La, Nd and Sm on the mechanical, heat conductivity and heat expansion properties of high entropy ceramics were discussed. The single-phase high-entropy ceramic materials in this work are very suitable for application as thermal barrier materials. [ABSTRACT FROM AUTHOR]

The temperature dependence of thermal conductivity and specific heat for detonated nanodiamond ceramics is investigated on specially designed experimental setups, implementing the uniaxial stationary heat flow method and the thermal relaxation method, respectively. Additionally, complementary studies with a commercial setup (Physical Property Measurement System from Quantum Design operating either in Thermal Transport or Heat Capacity Option) were performed. Two types of samples are under consideration. Both ceramics were sintered at high pressures (6–7 GPa) for 11–25 s but at different sintering temperatures, namely 1000 °C and 1600 °C. The effect of changing the sintering conditions on thermal transport is examined. In thermal conductivity κ(T), it provides an improvement up to a factor of 3 of heat flow at room temperature. The temperature dependence of κ(T) exhibits a typical polycrystalline character due to hindered thermal transport stemming from the microstructure of ceramic material but with values around 1–2 W/mK. At the lowest temperatures, the thermal conductivity is very low and increases only slightly faster than linear with temperature, proving the significant contribution of the scattering due to multiple grain boundaries. The specific heat data did not show a substantial difference between detonated nanodiamond ceramics obtained at different temperatures unlike for κ(T) results. For both samples, an unexpected upturn at the lowest temperatures is observed—most likely reminiscent of a low-T Schottky anomaly. A linear contribution to the specific heat is also present, with a value one order of magnitude higher than in canonical glasses. The determined Debye temperature is 482 (±6) K. The results are supported by phonon mean free path calculations. [ABSTRACT FROM AUTHOR]

The additive composition of an AlN ceramic substrate material was optimized to achieve high strength and thermal conductivity. MgO-CaO-Al 2 O 3 -SiO 2 (MCAS) glass and Y 2 O 3 were used as basic additives for improved sintering properties and thermal conductivity, thereby allowing for AlN to be sintered at a relatively low temperature of 1600 °C without pressurization. Yttria-stabilized zirconia (YSZ) was added (0–3 wt%) to further improve the strength of the AlN ceramic. YSZ and Y 2 O 3 reacted with AlN to produce ZrN, Y 4 Al 2 O 9 , and Y 3 Al 5 O 12 secondary phases. The formation of these yttrium aluminate phases improved the thermal conductivity by removing oxygen impurities, while ZrN formed at the AlN grain boundaries provided resistance to grain boundary fractures for improved strength. Overall, the AlN ceramic with 1 wt% MCAS, 3 wt% Y 2 O 3 , and 1 wt% YSZ exhibited excellent thermal and mechanical properties, including a thermal conductivity of 109 W/mK and flexural strength of 608 MPa. [ABSTRACT FROM AUTHOR]

Highly optically transparent polycrystalline fluorapatite ceramics with hexagonal crystal structures were fabricated via a liquid-phase synthesis of fluorapatite powder, followed by spark plasma sintering (SPS). The effect of sintering temperature, as observed using a thermopile, on the optical transmittance and microstructure of the ceramics was investigated in order to determine suitable sintering conditions. As a result, high optical transmittance was obtained in the SPS temperature range of 950–1100 °C. The highest optical transmittance was obtained for the ceramic sample sintered at 1000 °C, and its average grain size was evaluated at only 134 nm. The grain size dramatically increased with temperature, and the ceramics became translucent at SPS temperatures above 1200 °C. The mechanical and thermal properties of the ceramics were measured to evaluate the thermal shock parameter, which was found to be comparable to or slightly smaller than that of single-crystal fluorapatite. This transparent polycrystalline fluorapatite ceramic material should prove useful in a wide range of applications, for example as a biomaterial or optical/laser material, in the future. Furthermore, the knowledge obtained in this study should help to promote the application of this ceramic material. [ABSTRACT FROM AUTHOR]

CeO 2 and Sc 2 O 3 co-stabilized ZrO 2 ceramics have attracted much attention as potential thermal barrier coatings (TBCs) materials for applications above 1300 °C. In this study, a series of Sc 0.04 Ce x Zr 0.96-x O 1.98 (SCZ, x = 0.08, 0.10, 0.12, 0.16) ceramic materials were synthesized with the solid-state method and their phase stability, microstructures and thermo-physical properties were systemically investigated by x-ray diffraction (XRD), Raman spectra, field emission scanning electron microscopy (SEM), thermal dilatometer, laser flash apparatus (LFA), and Vickers hardness tester. The results showed that Sc 0.04 Ce 0.12 Zr 0.84 O 1.98 (4S12CZ) and Sc 0.04 Ce 0.16 Zr 0.80 O 1.98 (4S16CZ) ceramic materials still maintained stable tetragonal phase structure after 100 h high temperature treatment at 1500 °C. SCZ had a high thermal expansion coefficient (TEC), low thermal conductivity, and high fracture toughness. The TEC of the ceramics increased with CeO 2 addition because lattice energy reduced with increasing substitution of Zr4+ by bigger Ce4+ while thermal conductivity decreased due to the increase of lattice distortion. Compared with 4S12CZ, 4S16CZ exhibited a higher fracture toughness of 6.48 ± 0.04 MPa m1/2 and showed the better anti-sintering property. Besides, the thermal conductivity, TEC and thermal cycling lifetime of 4S16CZ were optimal. The comprehensive performance of 4S16CZ suggested it could be explored as a promising TBC material for high-temperature application. [ABSTRACT FROM AUTHOR]

Ultra high temperature ceramics (UHTC) with good mechanical properties and thermal physical properties, including high melting point (>30000C), high conductivity, high thermal conductivity, high thermal shock resistance rate, provides a sharp leading edge and smooth surface of a new generation of aerospace vehicle design to the aerospace industry; Due to ultra-high temperature ceramic materials with high strength, oxidation resistance and thermal shock resistance, it can be applied to extreme environments such as hypersonic flight, atmospheric reentry and rocket propulsion system, and have been widely used in key components of aircraft front cone, engine, wing and engine hot end. Based on the application of ultra-high temperature superconducting materials in practical application, the solid modeling of ultra-high temperature superconducting front-end components of ultra-high speed aircraft wing is carried out by using ABAQUS software, the ultra-high temperature thermal field of loaded aircraft flying at ultra-high speed is simulated, the stress-strain field at the flange is obtained, and the thermal mechanical coupling analysis is carried out. [ABSTRACT FROM AUTHOR]

The way to achieve better energy efficiency in buildings is to improve their thermal insulation properties. This can be done by increasing the porosity of the ceramic materials by introducing pore-forming additives to the clay for production of lightweight ceramic panels. Compositions and properties of lightweight ceramic panels from marl clay and rice husks as lightweight aggregate were investigated. The lightweight ceramic panels from marl clay and rice husks with sizes 5x5x1 cm were produced by dry pressing and following firing at 1000°C. The influence of the amount of rice husks of 15, 30, 50 and 65 mass % on the properties of light ceramic samples fired at 1000°C has been established. Apparent density, apparent porosity, thermal conductivity and compressive strength were measured. The thermal conductivity is reduced from 1.0 W mK-1 (in ceramic panels without rice husks) to 0.6 W mK-1 (ceramic panels with 30 mass % rice husks) at standard compressive strength of 10 MPa. This quantity of rice husks is recommended for the composition of light porous ceramic materials for heat isolation in intelligent house. [ABSTRACT FROM AUTHOR]

Thermoelectric materials can easily realize energy savings by converting untapped waste heat into electricity. Unfortunately, however, the coupling of the thermoelectric parameters limits the conversion efficiency. Herein, we fabricated titanium oxide ceramic thermoelectric materials using a simple one-step solid-state reaction between TiO2 and starch at high temperature, and improved the electrical and thermal transport properties simultaneously by adjusting the amount of starch during preparation. With increasing starch, the electrical conductivity and power factor increased and the thermal conductivity decreased significantly. The samples mixed with 7 wt% starch showed rather low thermal conductivity (less than 2.0 W m−1 K−1) and a dimensionless figure of merit (ZT) close to 0.14K at 973 K. When the samples were sintered in an argon atmosphere, the starch was carbonized in situ into carbon and provided a reducing atmosphere, leading to the appearance of oxygen vacancies in the lattice of titanium oxide. The oxygen vacancies increased with increasing starch in the mixture during preparation, which resulted not only in a narrower band gap of titanium oxide but also enhanced phonon scattering. [ABSTRACT FROM AUTHOR]

A novel negative thermal expansion (NTE) material composed of Sm0.85Sr0.15MnO3-δ was synthesized using the solid-state method. By allowing Sr2+ to partially replace Sm3+ in SmMnO3, the ceramic material Sm0.85Sr0.15MnO3-δ exhibits NTE properties between 360K and 873K, and its average negative thermal expansion coefficient was −10.08 × 10−6/K. The structure of Sm0.85Sr0.15MnO3-δ is orthogonal, the space group is pbnm, the morphology is regular, and the grain size is uniform. The results of X-ray diffraction and XPS (X-ray photoelectron spectroscopy) suggest that the NTE phenomenon is related to the electron transfer of Mn ions. With the increase in temperature, Mn4+ is rapidly transformed into Mn3+, accompanied by Mn4+O6 octahedron distortion and oxygen defects. It was found that the sample volume continually decreased at the same time. [ABSTRACT FROM AUTHOR]

AlN is regarded as a promising ceramic material for high performance structural and high temperature applications due to its superior properties such as high thermal conductivity, excellent stability and wear resistance. However, challenges remain in fabricating AlN ceramics with high strength and high thermal shock resistance. In this work, AlN/YAlO 3 composites with different YAlO 3 contents (3–10 wt%) were prepared by a simple pressureless sintering method, and the impact of YAlO 3 content on mechanical properties and thermal shock resistance of AlN/YAlO 3 composites was investigated. Results show that the grain growth of AlN is inhibited and the densification is improved with the addition of 3 wt% and 5 wt% YAlO 3. Hence, the flexural strength and fracture toughness of AlN/YAlO 3 composites are improved due to the grain refinement and compactness enhancement, and the highest value, 369 MPa and 3.84 MPa m1/2, are reached by the AlN-5 wt% YAlO 3 composite. Moreover, the thermal shock resistance was assessed through theoretical forecast and cyclic thermal shock tests over a temperature range between 1000 °C and 1600 °C. Comparing with pure AlN, the thermal stress damage resistance parameters (R IV ) of AlN/YAlO 3 composites were increased, while their residual strengths and retention ratios after 10–50 cycles of thermal shock tests maintained a higher level as well. Microstructure analysis revealed that the thermal shock resistance of AlN/YAlO 3 composites was evidently improved attributing to various strengthening mechanisms such as crack deflection, crack branching and microcrack toughening. [ABSTRACT FROM AUTHOR]

• NdHfO composites materials and NdHfO "stuffed" pyrochlore solid solutions. • Thermal conductivity, luminescence, and oxygen ion conductivity were studied. • (Nd 2- x Hf x)Hf 2 O 7+ x /2 (x = 0.2) composite shows the lowest thermal conductivity. • (Nd 2- x Hf x)Hf 2 O 7+ x /2 (x = 0.2, 0.32) composites show the highest conductivity. • Narrow-band luminescence of the NdHfO composites has been observed. The phase composition, microstructure, electrical and thermal conductivity of Nd 2± x Hf 2± x O 7±δ ceramic materials have been studied. (Nd 2- x Hf x)Hf 2 O 7+ x /2 (x = 0.2, 0.32, 0.39) composites, containing 4–16 wt% HfO 2 , have the highest conductivity and the brightest narrow-band luminescence among materials under study. The (Nd 2- x Hf x)Hf 2 O 7+ x /2 (x = 0.2) composite, containing ∼ 4 wt% HfO 2 , is shown to have the lowest thermal conductivity: 1.52 W m–1 K–1 at 300 K. XRD and Raman spectroscopy results show that (Nd 2- x Hf x)Hf 2 O 7+ x /2 (x = 0.2, 0.32, 0.39, 1.14) are composites consisting of a mixture of pyrochlore solid solutions with Hf on the Nd site and two HfO 2 polymorphs (m - HfO 2 and γ 2 - HfO 2 nanodomains). The properties of the (Nd 2- x Hf x)Hf 2 O 7+ x /2 (x = 0.2, 0.32, 0.39, 1.14) composites are compared to that of the Nd 2 (Hf 2- x Nd x)O 7- x /2 (x = 0, 0.1) pyrochlores, and the best properties were shown by the (Nd 2- x Hf x)Hf 2 O 7+ x /2 (x = 0.2, 0.32) composites. [Display omitted] [ABSTRACT FROM AUTHOR]

Clays from Alhabia (Almería, Spain) have been investigated in this work using several analytical techniques: X-Ray Diffraction (XRD), X-Ray Fluorescence (XRF), thermal analysis (Thermogravimetry, TG, and its first derivative, DTG), Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray Spectroscopy (EDS). Texture characteristics (granulometry) and plasticity have been examined. The main ceramic properties (firing shrinkage, water absorption, bulk density, open porosity, flexural strength and thermal conductivity) have been determined using pressed and fired clay samples. Thus, the mineralogical, chemical, textural and ceramic features of these clays have been evidenced for the first time. The mineralogical analysis by XRD indicated that the clay samples are constituted by a mixture of chlorite and illite, as main clay minerals, being quartz and other minerals in lower relative proportion (calcite, gypsum and hematite). This finding is important because the investigations on chlorite-illite-calcitic clays are very scarce. The chemical analysis by XRF showed that silica and alumina are predominant, as expected by the mineralogy, with medium contents of calcium oxide, from calcite, and alkalis, from illite, being ∼8 and ∼5%, respectively, besides iron and titanium oxides (∼8%). The particle size analysis showed 71.76% of "clay fraction" (<2 μm) and 21.66% of silt fraction (2–50 μm). The plasticity index (Atterberg) was 14.3%, with acceptable moulding and extrusion properties. Thermal analysis by TG/DTG indicated a weight loss associated to dehydroxylation of structural water of the clay minerals and decarbonation of calcite by progressive heating. After the characterization of raw clays, the next step was the determination of ceramic properties of mixed and ground clays after firing using pressed bodies. For this purpose, two firing temperatures were selected (900 and 1100 °C) for 1 h. The examination of the resultant fired bodies indicated that porous ceramic materials (∼36% open porosity and ∼22% of water absorption capacity) can be obtained by firing at 900 ᵒC, with small variations in dimensions (<0.8% at 1100 °C). The porosity changed at relatively lower values by firing at 1100 °C (∼34–35%), being associated to the presence of decomposed calcite. Bulk density was found almost constant from 900 to 1100 °C, with a maximum value of ∼1.67 g/cm3 at 1100 °C. Flexural strength reached a maximum value of 34.47 MPa at 1100 °C for the ground sample. Finally, thermal conductivity after firing the clay bodies was found almost constant at 900 and 1100 °C (0.457 and 0.479 W/mK, respectively). Taking into account these results, the main applications of the Alhabia clays have been evaluated. These clays can be used for the fabrication of porous ceramic supports and tiles by firing at 900 °C. Firing the clays at higher temperature (1100 °C) is of great interest for the fabrication of ceramic tiles and ceramic bricks of higher flexural strength with variable porosity and practically constant in dimensions. It is economically important although at higher processing costs. Finally, it can be emphasized that this work is a contribution of a better scientific knowledge of chlorite-illite-calcitic clays as ceramic raw materials. [ABSTRACT FROM AUTHOR]

Boride ceramics are materials of choice in extreme conditions. Among them, titanium borides have many applications due to their high hardnesses and melting points. The behavior of titanium borides may not be easily studied at very high pressures and temperatures by experimental means. Alternatively, molecular dynamics (MD) is a powerful computational tool to investigate the desired behavior of materials in certain conditions. In this study, we develop an interatomic potential for the Ti B system based on the second nearest-neighbor modified embedded atom method (2NN-MEAM) formulation. With the developed potential, MD simulations reproduce many physical, mechanical, and thermal properties of titanium borides with good accuracy. As an application of the developed potential, a series of nanoindentation simulations is also conducted to investigate the temperature dependence of the nanohardness of TiB 2 up to 1500 K. The results illustrate a linear dependence between nanohardness and temperature. [Display omitted] • We developed a 2NN-MEAM interatomic potential for the Ti B system. • The predicted properties of titanium borides agree with the experimental data. • Nanoindentation simulations of TiB 2 are performed at various temperatures. • Our simulations predict a linear decline of the nanohardness of TiB 2 in 0 K ∼ 1500 K. [ABSTRACT FROM AUTHOR]

Zirconium dioxide (ZrO2) is one of the ceramic materials with high potential in many areas of modern technologies. ZrO2 doped with 8 wt.% (~4.5 mol%) Y2O3 is a commercial powder used for obtaining stabilized zirconia materials (8 wt.% YSZ) with high temperature resistance and good ionic conductivity. During recent years it was reported the co-doping with multiple rare earth elements has a significant influence on the thermal, mechanical and ionic conductivity of zirconia, due complex grain size segregation and enhanced oxygen vacancies mobility. Different methods have been proposed to synthesize these materials. Here, we present the hydrothermal synthesis of 8 wt.% (~4.5 mol%) YSZ co-doped with 4, 6 and 8 wt.% La2O3, Nd2O3, Sm2O3 and Gd2O3 respectively. The crystalline phases formed during their thermal treatment in a large temperature range were analyzed by X-ray diffraction. The evolution of phase composition vs. thermal treatment temperatures shows as a major trend the formation at temperatures >1000 °C of a cubic solid solutions enriched in the rare earth oxide used for co-doping as major phase. The first results on the thermal conductivities and impedance measurements on sintered pellets obtained from powders co-doped with 8 wt.% Y and 6% Ln (Ln = La, Nd, Sm and Gd) and the corresponding activation energies are presented and discussed. The lowest thermal conductivity was obtained for La co-doped 8 wt.% YSZ while the lowest activation energy for ionic conduction for Gd co-doped 8 wt.% YSZ materials. [ABSTRACT FROM AUTHOR]

Ceramic is a type of material for the cladding of façades that affords protection and contributes to the aesthetics of the building. Nevertheless, this type of cladding can develop defects such as water penetration and detachment. Passive Infrared Thermography is a type of nondestructive testing used to identify these defects. Its results are strongly influenced by the intensity of the heat source (the sun). They are also affected by the cladding material, as the thermal properties of the material are influenced by its physical properties, such as porosity. In this study, passive thermography is used to detect detachment and humidity in ceramic panels of different porosities. The thermal parameters were evaluated 14 h before and after the incidence of direct sunlight. The tools used to interpret the thermograms were visual analysis and contrast functions. The results show that all three methods identified the defects and the influence of the material porosity. The most representative difference was found in the ceramics of greater porosity, especially at higher temperatures, and in the cooling period for the less porous ones. The evolution of the thermographic contrasts showed that in the cycle of incident heat, the differences between the two porosities were significant, indicating that this is a good strategy for evaluating anomalies in façades. [ABSTRACT FROM AUTHOR]

Ceramic matrix materials have attracted great attention from researchers and industry due to their material properties. When used in engineering systems, and especially in aero-engine applications, they can result in reduced weight, higher temperature capability, and/or reduced cooling needs, each of which increases efficiency. This is where high-temperature ceramics have made considerable progress, and ceramic matrix composites (CMCs) are in the foreground. CMCs are classified into non-oxide and oxide-based ones. Both families have material types that have a high potential for use in high-temperature propulsion applications. The oxide materials discussed will focus on alumina and aluminosilicate/mullite base material families, whereas for non-oxides, carbon, silicon carbide, titanium carbide, and tungsten carbide CMC material families will be discussed and analyzed. Typical oxide-based ones are composed of an oxide fiber and oxide matrix (Ox-Ox). Some of the most common oxide subcategories are alumina, beryllia, ceria, and zirconia ceramics. On the other hand, the largest number of non-oxides are technical ceramics that are classified as inorganic, non-metallic materials. The most well-known non-oxide subcategories are carbides, borides, nitrides, and silicides. These matrix composites are used, for example, in combustion liners of gas turbine engines and exhaust nozzles. Until now, a thorough study on the available oxide and non-oxide-based CMCs for such applications has not been presented. This paper will focus on assessing a literature survey of the available oxide and non-oxide ceramic matrix composite materials in terms of mechanical and thermal properties, as well as the classification and fabrication methods of those CMCs. The available manufacturing and fabrication processes are reviewed and compared. Finally, the paper presents a research and development roadmap for increasing the maturity of these materials allowing for the wider adoption of aero-engine applications. [ABSTRACT FROM AUTHOR]

In order to assess the feasibility of utilizing soapstone waste, which is generated during the production of stone blocks for fireplaces and other energy-saving devices, the effect of its addition to clay on the technological and thermal properties of ceramic materials was investigated. Two local clays and soapstone processing waste were characterized using XRD, SEM-EDS, XRF, DTA-TG, and granulometric analysis. The linear firing shrinkage, water absorption, density, flexural strength, thermal conductivity, specific heat capacity, and thermal shock resistance of the fired ceramic samples were analyzed. The results have shown that addition of soapstone waste to clay in an amount of 40 wt.% increases flexural strength, enhances thermal stability, and, additionally, reduces the thermal conductivity of the experimental samples. The technological properties of the final product meet the standard requirements for ceramic tiles. [ABSTRACT FROM AUTHOR]

The consumption of colossal quantities of materials in the building industry has advanced the swift depletion of clean clay reserves. The use of organic additives in brick production is conserving clay resources. In addition, in some cases, it can lead to improvements in some material properties, such as decreasing thermal conductivity and increasing the capacity of the ceramic material in terms of thermal insulation. In the present investigation, waste millet husk (WMH) was incorporated in different proportions to clays to ascertain its influence on the fired brick properties. The raw materials were characterized for their physical, chemical, and thermal properties and found suitable for use in fired brick production. Additionally, the prepared modeled brick samples were tested for their physico‐mechanical properties. The results indicated that linear shrinkage and weight loss increased, whereas bulk density decreased from 2.06 to 1.58 g/cm3 depending on WMH incorporation amount in the clays and firing temperature. Similarly, compressive strength reduced by up to 68%. Thermal conductivity beneficially reduced by 42% with the addition of 16 wt.% of WMH. The best results in terms of mechanical properties were obtained with 4 wt.% of the WMH. In terms of thermal insulation, the best results were exhibited in the samples admixed with 16 wt.% of WMH. The results showed that porosity and bulk density were critical determining factors that directly influence the bricks physico‐mechanical properties. [ABSTRACT FROM AUTHOR]

This paper investigates the vibration characteristics of a sandwich nanosensor plate composed of piezoelectric materials, specifically barium and cobalt, in the upper and lower layers, and a core material consisting of either ceramic (silicon nitride) or metal (stainless steel) foams reinforced with graphene (GPRL). The study utilized the novel sinosoidal higher-order deformation theory and nonlocal strain gradient elasticity theory. The equations of motion for nanosensor sandwich graphene were derived using Hamilton's principle, considering the thermal, electroelastic, and magnetostrictive characteristics of the piezomagnetic surface plates. These equations were then solved using the Navier method. The core element of the sandwich nanosensor plate can be represented using three distinct foam variants: a uniform foam model, as well as two symmetric foam models. The investigation focused on analyzing the dimensionless fundamental natural frequencies of the sandwich nanosensor plate. This analysis considered the influence of three distinct foam types, the volumetric graphene ratio, temperature variation, nonlocal parameters, porosity ratio, electric and magnetic potential, as well as spring and shear viscoelastic support. Furthermore, an analysis was conducted on the impact of the metal and ceramic composition of the central section of the sandwich nanosensor plate on its dimensionless fundamental natural frequencies. In this context, the use of ceramic as the central material results in a mean enhancement of 33% in the fundamental natural frequencies. In contrast, the incorporation of graphene into the core material results in an average enhancement of 27%. The thermomechanical vibration behavior of the nanosensor plate reveals that the presence of graphene-supported foam and a viscoelastic support structure in the core layer leads to an increase in thermal resistance. This increase is dependent on factors such as the ratio of graphene, porosity ratio of the foam, and parameters of the viscoelastic support. Metal foam or ceramic foam has been found to enhance thermal resistance when compared to solid metal or ceramic core materials. The analysis results showed that it is important to take into account the temperature-dependent thermal properties of barium and cobalt, which are piezo-electromagnetic materials, and the core layer materials ceramics and metal, as well as the graphene used to strengthen the core. The research is anticipated to generate valuable findings regarding the advancement and utilization of nanosensors, transducers, and nano-electromechanical systems engineered for operation in high-temperature environments. [ABSTRACT FROM AUTHOR]

The southern island of the Philippines is abundant in silicate minerals, including the province of Lanao del Norte. However, some of these resources in the region are untapped for use as raw materials in the production of various ceramic products for industrial, pharmaceutical, and nanotechnology applications. These could include tiles, sanitary ware, dinnerware, insulating bricks, porcelain, membranes and coatings. Some of the explored minerals are the red clay in the municipality of Linamon, diatomaceous earth in Kapatagan and black cinder in Salvador. It is the aim of this study that these minerals are evaluated in terms of their physical and chemical properties so that these will be used for optimum application. The properties that were determined were their specific gravities, raw and fired surface colors, Atterberg limits, particle size distribution, thermal properties, morphologies and mineralogical compositions. Pellets were formed for each raw material and fired at two temperature levels 1000 °C and 1200 °C to evaluate their physical properties. Linamon red clay has a 38.88% cumulative passing size of 150 µm, and the black cinder of Salvador and diatomaceous earth of Kapatagan have cumulative passing sizes of 96.53% and 60.12% at 150-micron sieve, respectively. The common mineral contents of the three samples are montmorillonite, quartz and andesine. Black cinder fired at 1200 °C has the darkest shade of red with a greasy quasi-submetallic luster. It attained the highest fusion coverage on the platform among the three materials, which makes it a potential supplement or replacement for feldspar in clay-based triaxial materials for ceramic production. The diatomaceous earth has the potential to be a secondary clay content source and a good source of flux for a certain temperature range. Both the red clay and diatomaceous earth were classified as plastic materials that are suitable for brick production, and the red clay is also feasible for pottery production. These are a few of the features of the clay minerals in the region that present suitable properties for application as raw materials in the production of ceramic tiles and hollow ceramic products. [ABSTRACT FROM AUTHOR]

Fabrication of ceramic materials containing high amount of porosity with controlled size and structure is a critical factor for various applications. In this study, porous alumina ceramics were prepared by addition of 5–30 vol% carbon black (CB) powders with different specific surface area (SSA) into the alumina matrix as a pore forming agent and application of partial sintering via spark plasma sintering (SPS) technique. After removal of CB particles from the ceramic structures, physical, mechanical, and thermal properties of the porous alumina ceramics were investigated. The open porosity level was detected between 38.48 and 59.81% depending on the type and amount of CB removed. The compressive strength of the sintered samples was measured as ∼150 MPa, which is ∼3 times higher than that of the conventionally sintered samples thanks to the strong neck formation between grains. The large pores formed by removal of CB agglomerates in case of using CB powders with SSA of 107 and 254 m2/g resulted in a change in thermal conduction mechanism from lattice vibration to thermal convection. [ABSTRACT FROM AUTHOR]

High calcium-fly ash (HCFA) collected from the Mae Moh electricity generating plant in Thailand was utilized as a raw material for ceramic production. The main compositions of HCFA characterized by X-ray fluorescence mainly consisted of 28.55wt% SiO2, 16.06wt% Al2O3, 23.40wt% CaO, and 17.03wt% Fe2O3. Due to high proportion of calcareous and ferruginous contents, HCFA was used for replacing the potash feldspar in amounts of 10wt%–40wt%. The influence of substituting high-calcium fly ash (0–40wt%) and sintering temperatures (1000–1200°C) on physical, mechanical, and thermal properties of ceramic-based materials was investigated. The results showed that the incorporation of HCFA in appropriate amounts could enhance the densification and the strength as well as reduce the thermal conductivity of ceramic samples. High proportion of calcareous and ferruginous constituents in fly ash promoted the vitrification behavior of ceramic samples. As a result, the densification was enhanced by liquid phase formation at optimum fly ash content and sintering temperature. In addition, these components also facilitated a more abundant mullite formation and consequently improved flexural strength of the ceramic samples. The optimum ceramic properties were achieved with adding fly ash content between 10wt%–30wt% sintered at 1150–1200°C. At 1200°C, the maximum flexural strength of ceramic-FA samples with adding fly ash 10wt%–30wt% (PSW-FA(10)–(30)) was obtained in the range of 92.25–94.71 MPa when the water absorption reached almost zero (0.03%). In terms of thermal insulation materials, the increase in fly ash addition had a positively effect on the thermal conductivity, due to the higher levels of porosity created by gas evolving from the inorganic decomposition reactions inside the ceramic-FA samples. The addition of 20wt%–40wt% high-calcium fly ash in ceramic samples sintered at 1150°C reduced the thermal conductivity to 14.78%–19.25%, while maintaining acceptable flexural strength values (∼45.67–87.62 MPa). Based on these promising mechanical and thermal characteristics, it is feasible to utilize this high-calcium fly ash as an alternative raw material in clay compositions for manufacturing of ceramic tiles. [ABSTRACT FROM AUTHOR]

In order to meet the urgent demand of new thermal barrier coating materials for a new generation of aero-engines,a high entropy rare earth tantalate (Y0.2Gd0.2Dy0.2La0.2Sm0.2)TaO4 material,abbreviated as (5RE0.2) TaO4, was developed using high-purity oxides (Y2O3, Gd2O3, Dy2O3, Sm2O3, La2O3, Ta2O5) as raw materials according to the stoichiometric ratio, and insulating at 1 200 - 1 750 °C for 5 h for a solid phase reaction. The phase composition, microstructure, thermal properties, mechanical properties, and CMAS (CaO-MgO-Al2O3-SiO2) corrosion resistance of the material were studied. The results show that: (1) the (5RE0.2)TaO4 ceramic material has a monoclinic structure with obvious ferroelastic domain; (2) the material fired at 1 750 °C exhibits extremely low thermal conductivity (1.65 W ⋅ m-1 ⋅ K-1,600 °C) and high thermal expansion coefficient (10.2 x 10-6 K-1,1 200 °C); (3) due to the unique ferroelastic toughening effect,the fracture toughness of the (5RE0.2)TaO4 material fired at 1 750 °C reaches 2.4 MPa ⋅ m12; (4) (5RE0.2)TaO4 reacts with CMAS melt forming a reaction layer, showing excellent corrosion resistance. [ABSTRACT FROM AUTHOR]

There is a developing interest in efficient materials in automobile and aerospace fields that involves the improvement of metal matrix composites (MMCs) with great properties which incorporate higher strength, hardness and stiffness, better wear and destructive resistance along with better thermal properties. This work deals with the evaluation of the mechanical and wear properties of the newly developed hybrid MMC of Al 5059/B4C/Al2O3 produced by stir casting method. The main aim of the work was to evaluate the mechanical properties of various MMCs fabricated with various weight proportions of ceramic particles (B4C and Al2O3). An increase in the tensile strength and the surface hardness was observed with the increase in the ceramic particles but there was a decrease in the percentage of elongation of the specimen. An increase in the ceramic content in the composite samples made the composite sample brittle (composite) from ductile (base metal). [ABSTRACT FROM AUTHOR]

High‐temperature proton conductors based on acceptor‐doped barium zirconate exhibit excellent chemical stability in atmospheres containing CO2 or H2O. However, due to their refractory nature, these conductors have a low grain growth rate, which negatively affects the overall electrical conductivity. A possible strategy for increasing the ionic conductivity of zirconates lies in the partial substitution of Zr‐ions with other isovalent dopants. In this work, we carried out systematic studies of the crystal structure, microstructure, hydration capacity, transport, and thermal properties of BaZr0.8–xSnxSc0.2O3–δ (x = 0, 0.1, and 0.2). According to X‐ray powder diffraction and scanning electron microscopy data, all studied ceramic samples have a cubic perovskite structure, whose average grain size decreases with tin doping. It is found that the composition with x = 0.1 exhibits the highest values in terms of total, ionic, grain, and grain‐boundary conductivities. The complex analysis of the obtained data shows that a low‐level substitution of Zr4+‐ with Sn4+‐ions is a competent approach for designing new proton‐conducting electrolytes attractive for high‐temperature applications. [ABSTRACT FROM AUTHOR]

Microwave foaming was used for the first time to rapidly fabricate the metakaolin-based porous geopolymers. Mechanical, thermal, and microstructural (optical and scanning electron microscope) investigations coupled with X-ray diffraction, Fourier-transform infrared spectroscopy, and nuclear magnetic resonance techniques were conducted to characterize the obtained foams. High porosity metakaolin-based porous geopolymers could be obtained at 4 min of foaming/curing. The effect of the sodium silicate solution content on the total porosity as well as the mechanical and thermal properties was investigated. The total porosity decreased firstly and then increased in the range of ∼74 to ∼84 vol% with the increase of Na 2 SiO 3 content. The foams with 47.7 wt% Na 2 SiO 3 exhibited the lowest thermal conductivity (0.104 W/mK) and the highest total porosity (83.2 vol%). The fabrication time, mechanical, and thermal properties were compared with those of foams obtained by the conventional direct foaming method. With this approach, the preparation time can be greatly reduced, and the compressive strength (1.89–2.04 MPa) and thermal conductivity (0.104–0.155 W/mK) of the materials obtained were not inferior to similar components obtained by other foaming routes. The rapidly obtained porous geopolymers with high porosity and high strength as well as low thermal conductivity can be employed as thermal insulation materials and ceramic precursors. [Display omitted] • An effective strategy for highly porous geopolymers (PGs) is developed. • Metakaolin-based PGs were fabricated within 4 min by microwave foaming. • The properties can be tailored by the sodium silicate solution addition. • The PG can be used as thermal insulation material and ceramics precursor. [ABSTRACT FROM AUTHOR]

In this paper, we investigate a metal composite prepared using a one-step pressing method, where Al–Si alloy acts as the phase change materials (PCMs) and Al 2 O 3 /AlN serve as the structural support materials. The alloy formation and PCM composite preparation are synthesized in a single step. The study aims to characterize the microstructure, thermodynamic, and thermal properties of the composite material. To assess the heat storage properties of the prepared composite PCMs at temperatures higher than 600 °C, a high-temperature test system is established using a high-frequency induction heater. Additionally, we explore how to improve the issue of liquid leakage under high-temperature conditions. The results demonstrate that Al 2 O 3 and AlN (ceramic materials) exhibit excellent chemical compatibility with Al–Si composite PCMs. After sintering, the ceramic materials form a strong bond with Al–Si, effectively retaining the liquid phase of Al–Si alloy within the composite material. Consequently, the Al–Si composite PCMs do not exhibit high-temperature liquid leakage under elevated conditions. Both Al 2 O 3 /Al–Si and AlN/Al–Si composites possess favorable high temperature heat storage properties. The phase change enthalpy of Al 2 O 3 /Al–Si composite reaches 400 kJ/kg, with a thermal conductivity of 36 W/(m·K). Similarly, the AlN/Al–Si composite achieves a phase change enthalpy of 404 kJ/kg and a thermal conductivity of 43 W/(m·K). Both composites fulfill the requirements for high-temperature heat storage applications. • Prepare Al–Si alloy at a low temperature of 750 °C. • Choose AlN as a novel ceramic material to enhance thermal properties for Al–Si alloy. • Employ in situ XRD to monitor crystal changes, unraveling synthesis mechanism. • High-temperature heat storage performance has been evaluated at 1000 °C. [ABSTRACT FROM AUTHOR]

In the present study, Blast Furnace Slag (BFS) waste was evaluated as a sustainable, cost-effective CaO, SiO 2 , Al 2 O 3 and MgO substitute for inorganic oxides for the production of frit, a raw material for glass ceramic production. Two different frits were prepared to compare a commercially available frit (F-STD) with frit produced using BFS waste (F-BFS). The samples were characterized by XRF, XRD, heating microscopy, dilatometry and TG-DTA to determine the chemical composition, phase formation and thermal properties. The frits were applied on steel using the electrostatic spray method and subsequently thermally treated at 830 °C for 4.5 min. The reference (GC-STD) and partially BFS-substituted glass ceramic (GC-BFS) coatings were examined by XRD, SEM-EDS and ICP-MS experiments. The main crystal phase for both samples was Ni-substituted fluorine mica (KLiNi 2 Si 4 O 10 F 2). GC-BFS was slightly more amorphous (70%) than GC-STD (69.1%), which was correlated with the thermal properties of the BFS waste. Likewise, ICP-MS analysis after a boiling citric acid test (ISO 28706-1: 2008) revealed that the GC-BFS had relatively higher chemical resistance. The total release from the reference sample (GC-STD) was 23.556 mg/L, whereas the total release from the sustainably produced sample (GC-BFS) was 21.451 mg/L, which was consistent with the XRD results. [ABSTRACT FROM AUTHOR]

Silicon carbide (SiC) ceramic is one of the most used ceramic materials due to its excellent mechanical and thermal properties but the cost is high in production. Three-dimensional (3D) manufacturing of ceramic materials provides the possibility to fabricate ceramic components with unique geometry structures and can save time and cost in producing form and function parts. In this paper, reaction bonded silicon carbide (RBSC) ceramic was fabricated through direct ink writing (DIW) technology. Reaction bonded silicon carbide (RBSC) means infiltration of carbon containing porous green parts with melting silicon, leading to form β-SiC. Remaining pores are filled by residual free silicon. Silicon carbide (SiC) based inks with different carbon black content at solid content of 36 vol% were prepared. The inks consisted of silicon carbide powder as inner filler, carbon black powder and low content sodium alginate as the binder. The effect of carbon black content on rheological behavior was studied. The results showed that the carbon black content played an important role in adjusting the viscosity, modulus and yield point. With the increasing carbon black content, shrinkage of the printed green parts decreased. When the carbon black content reached 20 wt%, the final DIW RBSC ceramics had low residual Si content. The maximum density, flexural strength and thermal conductivity were 2.91 g/cm3, 229 MPa, and 132 W/(m·K), respectively. This study shows a bright prospect of this innovated 3D printing technology for flexibly producing complex and net-shaped RBSC ceramic parts. [ABSTRACT FROM AUTHOR]

In this paper, tin-phosphate amorphous glass and nano-crystallized ceramic materials were synthesized by sol-gel methods and heat treated at 400 °C with the composition of x SnO 2 − (100- x)P 2 O 5 (x SnP: ' x ' from 40 to 90 mol%). The electrical and thermal properties of tin-phosphate materials were investigated by electrical impedance spectroscopy (EIS) and thermogravimetry – differential thermal analysis – mass spectroscopy (TG–DTA–MS). Moreover, the local structure of x SnP was characterized by 119Sn-Mössbauer and magic angle spinning (MAS) 31P NMR spectroscopies. Homogeneous glasses were obtained for x SnP with ' x ' from 50 to 80, while Sn(HPO 4), SnO 2 , and Sn 3 (PO 4) 2 nanoparticles formed in 40SnP and 90SnP compositions, respectively. The nano-crystallized 40SnP and 90SnP samples showed large electrical conductivity (σ) of 2.02×10−5 and 1.04×10−4 S cm−1 due to the conductive crystalline phases of SnP 2 O 7 and defective SnO 2 , respectively. The lower σ of about 10−8 S cm−1 were recorded for x SnP with ' x ' from 50 to 80 owing to the decomposition of the 3D network built by phosphate tetrahedrons. 119Sn-Mössbauer spectra proved the growing number of SnIVO 6 units, which do not contribute to the rise of electrical conductivity. On the other hand, larger σ values of 1.79×10−4 and 6.4×10−3 S cm−1 were confirmed for 40SnP and 90SnP samples after heat treatment, resulting in partial reduction of SnIV to SnII and growing of the 3D network structure by PO 4 3−. It is concluded that highly electrically conductive x SnP samples can be synthesized by the sol-gel method followed by slow heat treatment. In addition, the battery evaluation was performed of x SnP samples as cathode and anode in a sodium-ion battery. The highest initial capacity recorded for 90SnP nano-crystallized ceramic at 37.97 mAh g−1 under a current rate of 20 mA g−1 with capacity retention (%) of 48.15% after 100 cycles as a cathode material. The anode test showed that the 40SnP nano-crystallized ceramic has the largest initial capacity of 375 mAh g−1 and after heat treatment 50SnP glass significantly increased to 425 mAh g−1 compared with 186 mAh g−1 before heat treatment. Also, the heat treatment effect on the initial capacity of 90SnP nano-crystallized ceramic with observation largest value of 470 mAh g−1. These results open the way to maybe applying these glass and nano-crystallized ceramic materials in all-solid-state batteries. • The x SnO 2 −(90− x)P 2 O 5 glass was successfully prepared with a wider chemical composition of SnO 2 concentration from 50 to 80 mol% by the sol-gel method. • The 40SnP and 90SnP samples exhibited notably high σ 's of 1.79×10−4 and 6.40×10−3 Scm−1 attributed to their elevated levels of proton conductivity. • 90SnP as cathode demonstrated the highest initial capacity, achieving 37.97 mAh g−1 and maintaining a capacity retention of 48.15% after 100 cycles. • 40SnP and 90SnP exhibited a large initial capacity of 375 mAh g−1 and 470 mAh g−1, as anode materials in SIBs. [ABSTRACT FROM AUTHOR]

The current study introduces porous ceramic materials fabricated from cenospheres through spark plasma sintering. The investigation delves into the impact of sintering temperature, mould diameter (20 and 30 mm), and cenosphere size on the resulting material properties. Notably, sample shrinkage initiates at 900 °C and demonstrates an upward trend with temperature escalation, while a larger mould diameter contributes to sample shrinkage. Elevated sintering temperature leads to increased apparent density across various sample series, such as CS 63–150 µm in a 20 mm mould (0.97 to 2.3 g/cm³ at 1050–1300 °C), CS 150–250 µm in a 20 mm mould (0.93 to 1.96 g/cm³ at 1050–1200 °C), and others in different mould sizes. Total porosity decreases from 61.5 % to 3.9 % with a rising sintering temperature (1050 to 1250 °C), while open porosity starts decreasing at lower temperatures. Closed porosity peaks in samples sintered at 1150 °C. Furthermore, an increase in sintering temperature from 1050 to 1300 °C boosts the compressive strength of CS 63–150 samples in a 20 mm mould from 11 MPa to 312 MPa. These findings align with the Rice model, illustrating an exponential relationship between compressive strength, material porosity, and fully dense material compressive strength. [ABSTRACT FROM AUTHOR]

The increase in operating temperature contributes to improving the performance and fuel utilization efficiency of gas turbines. However, it also places thermal barrier coatings (TBCs) in a more demanding working environment, requiring higher sintering resistance and better mechanical properties. In the present study, HfO2 was introduced into the dual‐phase LaYbZr2O7 system as a doping oxide to form the LaYb(HfxZr1−x)2O7 system. The research concentrated on its phase composition, mechanical properties, and thermophysical properties. The results show that substituting Hf for Zr does not alter the dual‐phase structure of the system. The mutual inhibition between the two phases and the inherent material‐binding capability of Hf further reduce the grain size compared to pure LYZO. Additionally, the presence of Hf reduces the tendency of Frenkel defect formation and cation migration frequency, effectively inhibiting ion diffusion and thereby suppressing the densification and shrinkage trends of the material. The system retains relatively high hardness, fracture toughness, and low elastic modulus of the LYZO matrix, with a decrease in thermal conductivity and an increase in infrared reflectivity. These results suggest that Hf doping enhances the sintering resistance of LYZO material, making them promising for high‐temperature TBCs. Our study presents a viable approach to enhance the sintering resistance of LYZO, and this methodology can be extrapolated to other rare‐earth zirconates. [ABSTRACT FROM AUTHOR]

Ceramic fibers are an important thermal insulation material that are not only widely used in extreme conditions, but also play an important role in energy conservation and energy efficiency for sustainable development. However, the practical application of conventional ceramic fibers has a high thermal conductivity in high-temperature environments, which hinders their widespread application. Here, a novel lamellar structured porous SiTiOC/C composite ceramic materials was designed and prepared with excellent thermal insulating properties. The unique microstructure endowed the porous SiTiOC/C composite ceramic materials with a high IR refractive index (93.81%) and an ultra-low thermal conductivity (0.0562 W·m−1 K−1 at 600 ℃). In addition, the porous SiTiOC/C composite ceramic materials not only exhibited excellent mechanical properties (4.46 MPa at 800 ℃), but also demonstrated impressive oxidation resistance and thermal stability. In summary, the proposed porous SiTiOC/C composite ceramic materials provide a reference for the development of high-temperature insulation with good mechanical properties. [ABSTRACT FROM AUTHOR]

As the international situation continues to change and conflicts in various countries intensify, improving national defense forces is a necessary condition to ensure the stable development of the country, and bulletproof armor is a key part of it. Pressureless sintered silicon carbide ceramics have been widely used in the field of bulletproof armor because of its simple preparation process and excellent mechanical properties of low density, high hardness and high strength. The hardness and fracture toughness of pressureless sintered silicon carbide bulletproof ceramics directly determine the quality of bulletproof performance. Promoting sintering densification and multi-phase composite sintering are the key ways to improve the hardness and fracture toughness of pressureless sintered silicon carbide ceramics. This sturdy summarizes the research progress of pressureless sintered silicon carbide bulletproof ceramic materials in recent years, focusing on the sintering aids, toughening methods, composite form of pressureless sintered silicon carbide bulletproof ceramic materials. [ABSTRACT FROM AUTHOR]

Improving fracture toughness, electrical conductivity, and biocompatibility has consistently presented challenges in the development of artificial bone replacement materials. This paper presents a new strategy for creating high-performance, multifunctional composite ceramic materials by doping graphene oxide (GO), which is known to induce osteoblast differentiation and enhance cell adhesion and proliferation into barium calcium zirconate titanate (BCZT) ceramics that already exhibit good mechanical properties, piezoelectric effects, and low cytotoxicity. Using fast hot-pressed sintering under vacuum conditions, (1 − x)(Ba0.85Ca0.15Zr0.1Ti0.9)O3−xGO (0.2 mol% ≤ x ≤ 0.5 mol%) composite piezoelectric ceramics were successfully synthesized. Experimental results revealed that these composite ceramics exhibited high piezoelectric properties (d33 = 18 pC/N, kp = 62%) and microhardness (173.76 HV0.5), meeting the standards for artificial bone substitutes. Furthermore, the incorporation of graphene oxide significantly reduced the water contact angle and enhanced their wettability. Cell viability tests using Cell Counting Kit-8, alkaline phosphatase staining, and DAPI staining demonstrated that the GO/BCZT composite ceramics were non-cytotoxic and effectively promoted cell proliferation and growth, indicating excellent biocompatibility. Consequently, with their superior mechanical properties, piezoelectric performance, and biocompatibility, GO/BCZT composite ceramics show extensive potential for application in bone defect repair. [ABSTRACT FROM AUTHOR]

New advances in carbon-based fillers (CBFs) as reinforcing agents have gained worldwide attention due to their novel properties and promising applications to obtain advanced composite materials with superior electrical, mechanical and thermal performance. These CBFs (carbon nanotubes (CNTs), carbon nanofibers (CNFs), graphene, graphene oxide, and graphite) are important for ceramic materials to make them more attractive for modern industry. These materials in the ceramic matrix can enhance various properties, such as mechanical, thermal, and electrical conductivity, as a sensor material for pressure and other environmental changes. This overview introduces the latest developments in the fabrication of Si 3 N 4 ceramics and the effect of CBFs as well SiC and SiC w on structural, mechanical, and thermal properties of Si 3 N 4 ceramics for next-generation electronic power devices. Moreover, we summarized the key aspects such as the fabrication approaches, influence of additive composition and concentration, and sintering parameters on the microstructure and overall performance of Si 3 N 4 ceramics. In particular, design strategies for scientists and engineers concerned about the manufacture of Si 3 N 4 substrate and active regeneration for the first time are proposed and discussed extensively. [ABSTRACT FROM AUTHOR]

Aluminum nitride (AlN) is a ceramic material with excellent dielectric and thermal properties, and it is used in the microelectron and energy fields. Despite polishing, the roughness (rms >10 nm) of AlN wafers fabricated by sintering fails to meet the surface requirements (rms <0.5 nm) for direct wafer bonding. However, rough-surface wafer bonding of paired AlN and AlN can be achieved with the following procedure: (1) rough surfaces are activated by oxygen plasma to introduce strong capillary action, (2) reactions of AlN and bonding species (OH−) are promoted by clamping during storage and annealing and (3) low-temperature annealing (<150 °C) joins the two surfaces of AlN/AlN by synthesizing Al 2 O 3 at the bonding interface. TEM and XPS results show that a transition layer exists between bonding surfaces wherein the concentration of nitrogen decreases while that of oxygen significantly increases. [ABSTRACT FROM AUTHOR]

Feldspars are the most abundant mineral in the earth's crust, however, their interest in ceramic industry goes beyond their abundancy. The unique compositional and structural features as well as the many outstanding properties that feldspars own, make them to be widely used as raw material for the ceramic industry. Moreover, multiple works have demonstrated that engineered feldspar-based ceramics are very promising for their use in applications such as ceramic tiles, dielectrics or phosphors, among others, and therefore, in this article, a comprehensive review on their dielectric, mechanical, optical and thermal properties is presented. This review intends to provide an up-to-date outlook of the possibilities that engineered feldspars offer to their application in ceramic industry, discussing future prospects and challenges that might ease the opening up of new horizons for future applications in ceramic sector. [ABSTRACT FROM AUTHOR]

Ceramic fibers have the advantages of high temperature resistance, light weight, favorable chemical stability and superior mechanical vibration resistance, which make them widely used in aerospace, energy, metallurgy, construction, personal protection and other thermal protection fields. Further refinement of the diameter of conventional ceramic fibers to microns or nanometers could further improve their thermal insulation performance and realize the transition from brittleness to flexibility. Processing traditional two-dimensional (2D) ceramic fiber membranes into three-dimensional (3D) ceramic fiber aerogels could further increase porosity, reduce bulk density, and reduce solid heat conduction, thereby improving thermal insulation performance and expanding application areas. Here, a comprehensive review of the newly emerging 2D ceramic micro-nanofiber membranes and 3D ceramic micro-nanofiber aerogels is demonstrated, starting from the presentation of the thermal insulation mechanism of ceramic fibers, followed by the summary of 2D ceramic micro-nanofiber membranes according to different types, and then the generalization of the construction strategies for 3D ceramic micro-nanofiber aerogels. Finally, the current challenges, possible solutions, and future prospects of ceramic micro-nanofiber materials are comprehensively discussed. We anticipate that this review could provide some valuable insights for the future development of ceramic micro-nanofiber materials for high temperature thermal insulation. [ABSTRACT FROM AUTHOR]

Magnesium matrix composites are essential lightweight metal matrix composites, following aluminum matrix composites, with outstanding application prospects in automotive, aerospace lightweight and biomedical materials because of their high specific strength, low density and specific stiffness, good casting performance and rich resources. However, the inherent low plasticity and poor fatigue resistance of magnesium hamper its further application to a certain extent. Many researchers have tried many strengthening methods to improve the properties of magnesium alloys, while the relationship between wear resistance and plasticity still needs to be further improved. The nanoparticles added exhibit a good strengthening effect, especially the ceramic nanoparticles. Nanoparticle-reinforced magnesium matrix composites not only exhibit a high impact toughness, but also maintain the high strength and wear resistance of ceramic materials, effectively balancing the restriction between the strength and toughness. Therefore, this work aims to provide a review of the state of the art of research on the matrix, reinforcement, design, properties and potential applications of nano-reinforced phase-reinforced magnesium matrix composites (especially ceramic nanoparticle-reinforced ones). The conventional and potential matrices for the fabrication of magnesium matrix composites are introduced. The classification and influence of ceramic reinforcements are assessed, and the factors influencing interface bonding strength between reinforcements and matrix, regulation and design, performance and application are analyzed. Finally, the scope of future research in this field is discussed. [ABSTRACT FROM AUTHOR]

Materials offering high energy density are currently desired to meet the increasing demand for energy storage applications, such as pulsed power devices, electric vehicles, high-frequency inverters, and so on. Particularly, ceramic-based dielectric materials have received significant attention for energy storage capacitor applications due to their outstanding properties of high power density, fast charge–discharge capabilities, and excellent temperature stability relative to batteries, electrochemical capacitors, and dielectric polymers. In this paper, we present fundamental concepts for energy storage in dielectrics, key parameters, and influence factors to enhance the energy storage performance, and we also summarize the recent progress of dielectrics, such as bulk ceramics (linear dielectrics, ferroelectrics, relaxor ferroelectrics, and anti-ferroelectrics), ceramic films, and multilayer ceramic capacitors. In addition, various strategies, such as chemical modification, grain refinement/microstructure, defect engineering, phase, local structure, domain evolution, layer thickness, stability, and electrical homogeneity, are focused on the structure–property relationship on the multiscale, which has been thoroughly addressed. Moreover, this review addresses the challenges and opportunities for future dielectric materials in energy storage capacitor applications. Overall, this review provides readers with a deeper understanding of the chemical composition, physical properties, and energy storage performance in this field of energy storage ceramic materials. [ABSTRACT FROM AUTHOR]

High-entropy carbide ceramic materials exhibited excellent thermal and mechanical properties, making them highly sought after in high-temperature applications. However, the oxidation resistance of high-entropy carbide ceramic needed to be further improved. This work unraveled the oxidation behavior and mechanism of high-entropy carbide ceramic by introducing the Cr 3 C 2. The results indicated that the oxidation rate of (TiZrTaNbCr)C initially decreased with temperature up to 900 °C, followed by an increased with further temperature rise up to 1100 °C. At 800 and 900 °C, the parabolic oxidation rate constants were 0.70 and 0.17 mg2cm−4min−1, respectively. And the minimum thickness of oxidized layer was 60 µm at 900 °C for 120 min. This unusual phenomenon suggested the formation of different oxidation products. Specifically, the CrNbO 4 and Nb 2 Zr 6 O 17 oxide layer were formed at 900 °C, leading to an increased resistance to oxygen diffusion. Subsequently, loose oxidation products of Nb 2 O 5 were formed after 1000 °C, hindering the oxidation resistance. In the current study on oxidation resistance of high entropy carbides, this work showed a competitive performance. Overall, this study illustrated the oxidation mechanism and behavior of (TiZrTaNbCr)C and proposed a new avenue for the design of high-entropy ceramic components. [ABSTRACT FROM AUTHOR]

Lithium-ion (Li-ion) batteries are widely used in high-performance energy storage applications because of their high energy density. However, safety concerns related to thermal runaway remain a significant challenge for Li-ion batteries. Electrolyte leakage and dendrite formation can trigger thermal runaway, and these factors typically damage traditional polyethylene (PE) separators. Consequently, these separators struggle under extreme conditions and fail to control dendrite growth. In this study, we proposed a solution by coating PE separators with graphene oxide (GO) layers. GO, as a ceramic material, provides superior thermal and mechanical stability compared with polymers. Moreover, GO-coated PE separators (GO-S) do not compromise the advantages of PE separators and effectively manage dendrite growth. In this study, the as-prepared GO-S exhibits excellent electrochemical properties in terms of high ionic conductivity, suppression of Li dendrite growth during charge/discharge process, and long-term cyclability for 7,000 h (3,500 cycles) as well as high thermal stability even after heat treatment of 100°C. Thus, we expect that this research can highlight the potential application of functionalized GO sheets in addressing the thermal and mechanical limitations of polymer-based separators, thereby enhancing the safety and reliability of Li-ion batteries. [ABSTRACT FROM AUTHOR]

The preparation of ceramic materials with complex porous structures through photopolymerization-based 3D printing requires the development of stable and printable slurries. In this study, zirconium acetylacetonate was incorporated into the thiol vinyl organosilicon prepolymer to create a photosensitive Si–Zr–O–C slurry. Regarding the natural bone structures and the Tyson polygon principle, a gradient pore structure was designed and then printed using a digital light processing 3D printer. After printing, the effects of sintering temperatures on the phase composition and structure of Si–Zr–O–C ceramics were systematically investigated. Subsequently, a comparative analysis of structure and properties was performed on sintered samples with different zirconium acetylacetonate contents. The results revealed that the sample containing 30 wt. % zirconium acetylacetonate exhibited a higher compressive strength of 9.70 ± 0.28 MPa and a lower room temperature thermal conductivity of 0.528 W m−1 K−1. This study confirmed the significant potential of using 3D printing technology to prepare Si–Zr–O–C precursor ceramics with a porous structure. [ABSTRACT FROM AUTHOR]

The microstructure is a critical factor governing the functionality of ceramic materials. Meanwhile, microstructural analysis of electron microscopy images of polycrystalline ceramics, which are geometrically complex and composed of countless crystal grains with porosity and secondary phases, has generally been performed manually by human experts. Objective pixel-based analysis (semantic segmentation) with high accuracy is a simple but critical step for quantifying microstructures. In this study, we apply neural network-based semantic segmentation to secondary electron images of polycrystalline ceramics obtained by three-dimensional (3D) imaging. The deep-learning-based models (e.g., fully convolutional network and U-Net) by employing a dataset based on a 3D scanning electron microscopy with a focused ion beam is found to be able to recognize defect structures characteristic of polycrystalline materials in some cases due to artifacts in electron microscopy imaging. Owing to the training images with improved depth accuracy, the accuracy evaluation function, intersection over union (IoU) values, reaches 94.6% for U-Net. These IoU values are among the highest for complex ceramics, where the 3D spatial distribution of phases is difficult to locate from a 2D image. Moreover, we employ the learned model to successfully reconstruct a 3D microstructure consisting of giga-scale voxel data in a few minutes. The resolution of a single voxel is 20 nm, which is higher than that obtained using a typical X-ray computed tomography. These results suggest that deep learning with datasets that learn depth information is essential in 3D microstructural quantifying polycrystalline ceramic materials. Additionally, developing improved segmentation models and datasets will pave the way for data assimilation into operando analysis and numerical simulations of in situ microstructures obtained experimentally and for application to process informatics. [ABSTRACT FROM AUTHOR]

Additive manufacturing technologies collectively refer to a set of layer-wise deposition methods that typically rely on CAD-CAM approaches for obtaining products with a complex shape/geometry and high precision and reliability. If the additive manufacturing of polymers is relatively easy and scalable due to the low temperatures needed to obtain processable inks, using similar technologies to fabricate ceramic products is indeed more challenging and expensive but, on the other hand, allows for obtaining high-quality results that would not be achievable through conventional methods. Furthermore, the implementation of additive manufacturing allows for the addressing of some important concerns related to the environment and sustainability, including the minimization of resource depletion and waste production/disposal. Specifically, additive manufacturing technologies can provide improvements in energy consumption and production costs, besides obtaining less waste material and less CO2 emissions, which are all key points in the context of the circular economy. After providing an overview of the additive manufacturing methods which are specifically applied to ceramics, this review presents the sustainability elements of these processing strategies, with a focus on both current and future benefits. The paucity of specific available studies in the literature—which are included and discussed in this review—suggests that the research on additive manufacturing sustainability in the field of ceramic materials is in the preliminary stage and that more relevant work still deserves to be carried out in the future to explore this fascinating field at the boundary among ceramics science/technology, production engineering and waste management. [ABSTRACT FROM AUTHOR]