NH3/CH4 co-firing is a promising low-carbon fuel strategy, yet its application in micro gas turbines is hindered by poor flame stability and high NOx emissions, especially in compact combustion chambers. Porous medium combustion (PMC) offers a potential solution, but the micro-scale combustion mechanisms within different ordered cell topologies remain unclear. To overcome this issue, three topological cell structures including tetrakaidecahedron (Ter), regular hexahedron (Cube), and biclinic hexahedron (Bi-Cube) were designed and fabricated with identical porosity (epsilon = 97%). By combining experiments and numerical simulations, a topology-mediated multi-field (flow-thermal-chemistry) analysis was established to reveal how cell geometry governs flow recirculation, heat redistribution, and reaction pathways. The results show that the Bi-Cube structure achieves the widest stable combustion range (4h = 0.6-1.6), a higher and more uniform temperature field (Tmax = 1315 degrees C), and reduces the NO peak by 450 ppm compared to the Ter structure (ENH3 = 50%, 4h = 0.9). This is attributed to the high-shear and high-recirculation flow field enabled by its rotational symmetry design, which allows efficient mixing and heat recirculation at low flow resistance, thereby promoting a uniform temperature distribution that suppresses localized hot spots and shifts the NO formation/reduction balance toward N2. As ENH3 increases, the dominant NO formation pathway shifts from CH3 oxidation/recombination competition to NH oxidation/reduction kinetics competition, with the transition at ENH3 approximate to 50%. The Bi-Cube further favors the NH -> N2 reduction pathway under this regime. This study elucidates topology-mediated fluid-thermal coupling effects on NH3/CH4 combustion, providing a rational design basis for efficient, low-emission co-firing technology in micro gas turbines.

Doping is a key strategy for enhancing the infrared radiative performance of spinel ceramics. However, the conventional selection of dopant species often relies on iterative experimentation. In this work, based on elemental structural characteristics and theoretical calculations, a strategic Cu/Co co-doping approach was adopted. A series of Mg0.8CuxCo0.2-xFe2O4 ceramics (x = 0, 0.05, 0.1, 0.15) were synthesized, which significantly improved the broadband infrared emissivity of MgFe2O4 spinel. The optimum composition (x = 0.1) exhibited outstanding broadband emissivity without noticeable selective absorption, making it a promising candidate for high-temperature energy-saving applications. This study demonstrates a synergistic co-doping strategy using Cu and Co ions to simultaneously engineer the band structure of MgFe2O4, achieving broader and flatter infrared emissivity than conventional single-doping approaches.

Ca2+/Cr3+ co-doped LaAlO3 has been regarded as an infrared radiation (IR) ceramic with great potential to realize energy conservation in high-temperature industry. However, the insufficient development of relevant coatings has hindered its practical implementation. To solve this problem, two La0.9Ca0.1Cr0.4Al0.6O3-delta coatings were respectively designed by using SiO2 sol and Al2O3 sol as binder, which can realize application at moderate temperature (<1200 degrees C) and higher temperature (<1400 degrees C). Both coatings maintained higher emissivity values, above 0.91/0.84 in the near/mid-infrared band (1-14 mu m) at room-temperature and 0.70 in the 1.3-10 mu m band at 1200 degrees C. By covering on Al2O3 & centerdot;SiO2 refractory substrate, these coatings displayed high bonding strength (>3.5 MPa, larger than conventional coating) and excellent thermal shock resistance (>68% residual bonding strength ratio after 20 times thermal shock). Additionally, the IR coating exhibited significant energy-saving effect, improving the surface temperature of heating source and achieving energy-saving ratio of 9.68% during water heating. These IR coatings have significant application potential for energy-saving in high-temperature industry.

In this work, an innovative approach, the incorporation of microporous MgO-MgFe2O4 aggregates, is proposed to enhance thermal insulation and performances of MgO-MgAl2O4 refractories for the cement rotary kilns. The results showed that compared with conventional dense MgO-MgAl2O4 refractories, the lightweight ones obtained a 29.2% lower thermal conductivity, mainly attributing to the presence of pores and low thermal conductivity MgFe2O4 phase in the microporous aggregates. During heating, minor Mg(Fe,Al)2O4 and microcracks formed at aggregates-matrix interface in lightweight refractories. The MgO-MgFe2O4 aggregates and formed microcracks can accommodate thermal expansion and induce crack propagation along interface between the aggregates and matrix, effectively improving the thermal shock resistance. Besides, the microporous MgO-MgFe2O4 aggregates could absorb part of the liquid glass phase in the matrix and improve viscosity of the penetrated liquid glass phase, which thus obviously enhanced both clinker resistance and coating adhesion property of the specimens.

Solid solar absorption/storage material (SSAM) is the crucial component for next generation concentrating solar power (CSP) system, which could promote global carbon neutrality. However, the comprehensive absorption/storage performance of SSAM at low cost has not been realized, thereby hindering its practical application. To address this problem, Fe/Si-rich copper slag, as abundant solid waste, was used as the main raw material to develop novel SSAM by introducing MgO/Al2O3 additives in present work. This kind of SSAM is composed of (Mg,Fe)(Fe,Al)2O4 spinel and (MgxFe2-x)SiO4 forsterite as main crystalline phases with high solar absorptance of 91.93%, due to impurity energy level absorption and lattice vibration absorption. Moreover, the material possesses excellent storage potential, including thermal storage density of 1194.83 J/g, thermal conductivity of 4.69 W/(m·K) and specific heat capacity of 1.37 J/(g·K). Crucially, the SSAM maintains remarkable mechanical integrity at elevated temperatures, exhibiting a bending strength of 77.96 MPa even at 1000 °C (106.23 MPa at room temperature). Furthermore, it demonstrates outstanding thermal shock resistance and superior high-temperature wear resistance, ensuring long-term operational reliability under harsh service conditions. This spinel/forsterite SSAM with high absorption/storage performance and low cost, displays significant potential for next generation CSP system.

MgO–C refractories are extensively employed in critical metallurgical equipment such as converters, electric arc furnaces and ladles, valued for their exceptional thermal shock resistance and slag corrosion resistance. However, the use of high-proportion scrap steel in low-carbon steelmaking processes accelerates the corrosive degradation of MgO–C refractories due to changes in slag basicity and viscosity. Enhancing the slag corrosion resistance of MgO–C refractories has thus become an urgent priority. The methods for evaluating the slag corrosion resistance of MgO–C refractories are systematically reviewed, the slag corrosion mechanisms are elucidated, and various strategies and recent advances for enhancing their slag corrosion resistance are summarized. The aim is to provide valuable insights and references for ongoing research in this field while outlining potential directions for future studies.

Commercial spinel-calcium aluminate (CMA) aggregates are limited in ladle applications by their high apparent porosity (similar to 21.5%), which severely degrades cyclic thermal shock resistance. To address the issues, this study employs high-temperature secondary sintering at 1600 degrees C to fabricate densified CMA (C-CMA) aggregates, and subsequently evaluates their thermal shock resistance under simulated ladle conditions using a supersonic frequency induction heating system. The resulting C-CMA aggregates exhibit a significantly reduced apparent porosity of 4.65% and a distinctive core-shell structure composed of dense CA2 and CA6 phases. Combined with an increased calcium aluminate (CA) phase content, this tailored microstructure markedly promotes solid-liquid phase transition during thermal cycling. Consequently, compared to refractory with conventional CMA aggregates, the enhanced heat storage capacity of refractory with C-CMA aggregates prolongs the cooling time by 81.86 s (+6.3%) and 119.98 s (+11.1%) after 1 and 3 cycles, respectively. Furthermore, the in situ generated liquid phase not only alleviates thermal stress but also continuously infiltrates and heals microcracks through an overflow mechanism. This results in significantly improved compressive strength retention, with increases of 2.63%-5.32% under cold-state conditions and 25.75% at high temperature. These findings demonstrated that microstructural engineering via secondary sintering can effectively transform conventional CMA into a functional and self-healing aggregate, providing a new strategy for the design of high-performance refractory.

Premature cracking during free hot deformation (FHD) of n-type Bi2Te2.7Se0.3 limits the attainable strain, thereby interrupting dynamic recrystallization (DRX) and capping (0001) basal-texture development. Here, we identify this crack-limited DRX bottleneck through thermomechanical compression and interrupted-deformation evidence, and then eliminate it using hot extrusion (HE), where the inherently triaxial compressive stress state suppresses crack initiation and propagation. Crack-free extrusion enables near-complete DRX and a near-ideal (0001) basal texture, while retaining ∼10 nm amorphous nanodomains, which contribute to reducing lattice thermal conductivity without degrading electrical transport. The optimized alloy is tougher-95.8 MPa in bending and 138.4 MPa in compression (+62%/+48% vs FHD)-and reaches zT ≈ 1.20 at 343 K. Importantly, under strictly identical single-stage micro-TEC assembly and test boundaries (identical p-legs; only n-legs varied), the extruded n-legs increase ΔTmax to an outstanding 75.8 K at Th ≈ 300 K, which is among the highest values reported for Bi2Te3-based TECs under comparable testing conditions. These results establish crack-free hot extrusion as a scalable route to remove the fracture-imposed DRX ceiling in layered brittle thermoelectrics and to translate microstructural gains into device-level cooling performance.

In Chinese tea culture, precise control of tea leaves steeping time is crucial during brewing. The thermodynamic properties of the ceramic Gaiwan directly affect the wall temperature of its handheld area. Based on the Chinese national standard Gaiwan, this study presented a comprehensive framework integrating experimental measurement, numerical simulation, and algorithmic optimization, as well as a coupled model of structural geometry, thermodynamic performance, and thermal comfort. Firstly, the profile contour of the Gaiwan was approximated by cubic uniform B-spline curves to construct a three-dimensional geometric model. Subsequently, the heat dissipation process was simulated with COMSOL Multiphysics to investigate the transient characteristics of the unsteady state temperature field of the ceramic Gaiwan. Simulation accuracy was experimentally validated. Next, a shape optimization method based on the genetic algorithm was introduced to optimize the contour curve of the Gaiwan's axial profile. Numerical calculations showed that the wall temperature in the handheld area of the optimized model was decreased by 12.43%. Finally, physical prototypes of both the benchmark and optimized models were fabricated via 3D printing technology for experimental validation. Comparative results indicated that the wall temperature in the handheld area of the optimized physical model was 28.51% lower than that of the benchmark model. This study significantly reduced the wall temperature in the handheld area of the ceramic Gaiwan, effectively avoiding the risk of burns due to excessive surface temperatures. Thus, it enhances the user experience for tea drinkers and provides scientific guidance for the manufacturing and production of the ceramic Gaiwan.

Zintl-phase Mg3(Sb, Bi)2 alloys have garnered significant attention, due to their abundance of constituent elements, non-toxicity, low cost, and intrinsically low thermal conductivity. However, their large-scale application remains limited by the stringent synthesis requirements. In this study, we report a scalable melting–SPS strategy to synthesize Mg3(Sb, Bi)2 alloys with precisely tuning the Bi content. Partial substitution of Sb by Bi effectively modulates carrier concentration and mobility, while the associated mass and strain field fluctuations, together with the softer Mg–Bi bonds, significantly enhance phonon scattering and reduce lattice thermal conductivity. The optimized composition Mg3.5SbBi0.99Te0.01 achieved a peak power factor of 23.56 μW cm−1 K−2 at 373 K, outperforming most reported Mg3(Sb, Bi)2 materials in the near room temperature range. It also delivers a high average ZT of 0.99, comparable to the commercial Bi2Te3-based alloys. Its room-temperature ZT of 0.83 surpasses most previously reported Mg3(Sb, Bi)2 materials. A peak ZT of 1.13 at 423 K further demonstrates this balanced and high performance across 300–773 K, highlighting the strong potential of the scalable fabrication route for practical thermoelectric applications.

This study explores the thermo-mechanical behavior of reticulated alumina foam ceramics and the influence of structural characteristics. Industrial and laboratory specimens with varied ppi-numbers and strut thickness were used, the latter prepared via two coating processes to introduce inner/outer layer inhomogeneity. Cylindrical splitting tests revealed that increases in foam weight and strut thickness enhance mechanical strength, while inhomogeneity reduces load-bearing capacity due to uneven stress distribution. Heavier foams showed more concentrated cracking and energy release. The inner/outer homogeneity gradient provided structural support, reducing early energy dissipation. High-temperature tests, including creep and refractoriness under load, showed that composition differences affected softening behavior, with high-ppi foams exhibiting better pressure transfer and creep resistance. Inhomogeneity had limited impact on softening resistance. This study can offer theoretical guidance for optimizing structure and fabrication of ceramic foam filters.

Addressing the critical challenge of thermo-mechanical failure in alumina-spinel castables under cyclic thermal shock, this study proposes a design strategy centered on engineered spinel-calcium aluminate aggregates with controlled phase-transition capability. However, the intrinsic relationship between phase-transition content, thermodynamic response, and mechanical behavior remains insufficiently understood. Guided by CALPHAD-based phase diagrams, aggregates with systematically graded liquid-phase content were designed and fabricated. Their thermo-mechanical behavior was simulated using a heterogeneous model implemented in FLAC3D, where the built-in FISH program language was employed to reconstruct a three-dimensional microstructure that accurately captures the random distribution of multiphase components (e.g., CA(2), CA(6), and CA). The model incorporates a strain-softening/hardening Mohr-Coulomb constitutive law to account for the effects of phase transition, including latent heat storage, viscous relaxation, and stress redistribution. Simulation results show good agreement with experimental data (error <5%). The findings reveal a systematic reduction in residual thermal stress after quenching with increasing content of low-melting-point calcium aluminate phases. The sample with the highest liquid-phase content exhibits the optimal resistance to cyclic thermal shock, as the in situ generated liquid simultaneously alleviates thermal stress through latent heat absorption and viscous damping, thereby suppressing crack initiation and promoting homogeneous stress redistribution during thermal cycling. These coupled mechanisms significantly improve both the thermo-mechanical resilience and the energy efficiency of alumina-spinel castables under extreme operating conditions.

The development of cost-effective and high-performance heat-absorption and thermal-storage media from industrial solid waste represents a crucial pathway for the large-scale utilization of renewable energy. However, conventional iron-rich metallurgical slags often suffer from poor phase and structural stability at elevated temperatures. In this study, an efficient phase reconstruction strategy is proposed to fabricate magnesium-ferrite/forsterite multiphase ceramics with both broad-band photon-trapping capabilities and superior thermo-mechanical reliability through the introduction of an optimal amount of magnesium oxide (MgO). Microstructural evolution analysis reveals that the addition of appropriate MgO converts the low-melting-point silicate glass phase into a dense dual-crystalline framework, which simultaneously locks high concentrations of low-valence iron (Fe²⁺) and oxygen vacancies (Ov) within the spinel lattice. The enrichment of these micro-active defects significantly enhances intervalence charge transfer (IVCT) between Fe²⁺ and Fe3+ ions, leading to a substantial contraction of the optical bandgap to 1.77 eV. Consequently, the SM-30 ceramic, prepared at a baseline sintering temperature of 1250 °C, achieves a solar spectrum-weighted absorptivity of 92.71%, a specific heat capacity of 0.90 J/(g·K), and a high thermal conductivity of approximately 5 W/(m·K). Furthermore, this multiphase ceramic demonstrates exceptional anti-wear performance under high-temperature dry sliding friction conditions, which is primarily attributed to the subtle viscous flow of the residual glass phase at grain boundaries under service temperatures. This behavior not only effectively dissipates local thermal expansion mismatch stress at the interface but also facilitates the in-situ formation of a dense, continuous liquid-phase lubrication film on the friction surface. Ultimately, this work provides a promising, environmentally friendly approach and a robust theoretical foundation for the design of low-cost, integrated heat-absorption and thermal-storage materials for next-generation Concentrating Solar Power (CSP) systems.

To overcome the limitations of disordered porous ceramics in micro gas turbines (MGTs) combustors, this study systematically evaluates the mechanical and thermal performance of disordered foams against three ordered SiC topologies (regular hexahedral RH, regular octahedral RO, and regular Kelvin RK). Coupled convection-radiation analysis demonstrates that structural periodicity significantly enhances multi-functional properties. Specifically, the RK topology exhibits superior heat transfer and temperature uniformity, while the RH and RO excel in mechanical strength and flow resistance, respectively. Mathematical models were established to quantify correlations between porosity, mechanical properties and heat transfer efficiency. Results indicate that while porosity dictates mechanical strength, heat transfer is synergistically controlled by both porosity and characteristic size. Notably, the RK achieves optimal comprehensive efficiency at 75.0% porosity and 6.0 mm edge length, providing a quantitative framework for the performance-driven design of SiC ceramic components in MGTs combustors.

The preparation of high-performance SiC reticulated porous ceramics (SRPC) is critical to ensuring the long-term service of SiC porous media burners. Aiming to synergistically improve the strength and oxidation resistance of the SRPC with multi-layered struts, residual stress was intentionally induced within the anti-oxidation layer by adjusting the coefficient of thermal expansion (CTE). The SRPC was prepared via SiC slurry coating and vacuum infiltration of alumina composite slurry, followed by spraying of LaAlO3 slurry, whose struts included SiC skeleton, transition layers and infrared radiation coating. Results showed that the residual compressive stress generated within anti-oxidation layer when the andalusite was introduced, resulting in an enhanced strength and water-oxygen corrosion resistance. The anti-oxidation layer with ZrO2 addition was peeling off due to the formed residual tensile stress. After 10 h of water-oxygen corrosion, the compression strength of the SRPC coated with LaAlO3 coating did not decrease, which was related to the formation of rod-like whiskers in the coating. This study provides valuable guidance for the preparation of medium materials utilized in high-temperature porous medium combustion.

The development of novel solid solar energy capture and storage materials (SSECSM) is essential for next-generation concentrated solar power (CSP) technology. In this study, novel MgO-Fe2O3 composites were synthesized for solar energy capture and storage through solid-phase sintering at varying sintering temperatures. The solar absorptivity, specific heat capacity (Cp), and abrasion resistance of the composites were investigated, and the mechanism of solar absorption enhancement was also analyzed. The solar absorptivity increased with sintering temperature due to the increase of Fe2+ content and oxygen vacancies; the Cp of composites increased with the MgO content. The overall performance of the samples was optimized when the MgO/Fe2O3 molar ratio was 3:1 and the samples were sintered at 1600 degrees C. The highest solar absorptivity of 82.5 % and Cp of 0.90 J/(gK), and low abrasion rate of 8.99 x 10(-6) mm(3)N-1 m(-1) were gained, which will provide a promising material for next-generation CSP technology.