Crack control remains a major challenge in laser-directed energy deposition (LDED) of oxide eutectic ceramics because of their intrinsic brittleness and thermal-stress accumulation. In this work, emissivity-calibrated in-situ infrared thermometry and thermo-mechanical simulation were used to reveal how circular oscillation scanning (COS) reduces the crack susceptibility of LDED Al2O3/GAP/ZrO2 eutectic ceramics. Compared with linear reciprocating scanning, COS produced a wider high-temperature zone, stronger interlayer reheating, and milder recooling. At the representative mid-height location, the average cooling rate from peak temperature to melting point decreased from 330.91 to 173.82 °C/s, while the reheating-induced temperature rise increased from 167.38 to 1076.03 °C. Stress analysis showed that COS reduced crack susceptibility mainly by weakening the continuous bottom-centered tensile-stress band and localizing higher-stress regions near the side areas, rather than by simply lowering the local stress peak. This stress redistribution was consistent with the observed transition from bottom-initiated vertical cracking to side-localized, laterally limited cracking. The COS parameter study further revealed a trade-off between thermal coverage and tensile-stress concentration. These findings provide guidance for scan-path design and crack control in LDED of oxide eutectic ceramics.

Establishing the correlation between the solidification microstructure and processing conditions has long been a fundamental prerequisite for achieving the desired properties, which requires an in-depth understanding of the specific material. In this work, the rapid solidification microstructure evolution of AlCoCrFeNi2.1 eutectic high-entropy alloy (EHEA) fabricated by laser powder-bed fusion was experimentally studied. Moreover, a single-track temperature field model was developed to capture the temporal and spatial variations in thermal gradient and solidification rate at the liquid-solid interface. The as-built AlCoCrFeNi2.1 EHEA featured several-micrometer eutectic colonies with ultra-fine lamellar structure inside. Through adjusting the scanning speed, the morphology of eutectic colonies transitioned from elongated to equiaxed, while the lamellar eutectic remained largely unchanged. By integrating experimental data with simulation results, a solidification map was established to describe the columnar-to-equiaxed transition (CET) behavior within the melt pool. The results showed that as the scanning speed increased from 550 to 1500 mm/s, a more pronounced CET trend was attributed to a reduced thermal gradient and a decrease in the ratio of thermal gradient to solidification rate. The good match between the experiments and simulations confirms the reliability of the solidification map. The relationship between process parameters, solidification conditions, and solidification structure can be effectively obtained.

Hexagonal boron nitride (h-BN) is an ideal filler for enhancing the thermal conductivity of polymer matrix thermal interface material (TIM) due to its superior thermal conductivity and exceptional electrical insulation properties. The thermal conduction performance of TIM is largely determined by the filler orientation and interface interaction between polymer matrix and fillers. In this work, glycine-modified h-BN (Gly-BN) was synthesized through ball milling-assisted ultrasonic liquid-phase exfoliation to strengthen the interface interaction between the filler and polymer matrix, and then, Gly-BN-filled epoxy resin (EP) composites with directionally arranged fillers were prepared by tape casting for the first time. Under the mechanical force of the casting scraper, Gly-BN was aligned horizontally, thereby establishing highly efficient heat transfer path. Thermal conductivity is enhanced with increasing the filler content, reaching 5.025 W/(m·K) with 40 wt.

Superalloys are extensively utilized in the aerospace and energy industries due to their outstanding high-temperature strength, thermal stability, and corrosion resistance. However, the rapidly growing demands for higher thrust-to-weight ratios and elevated turbine inlet temperatures in advanced engines have posed significant challenges to current hot-section component materials. Ceramics, with their inherent high hardness and melting points, are promising reinforcement candidates. Incorporating ceramics into superalloys enables the design of composites that overcomes the intrinsic limitations of conventional alloys. The newly-developed laser powder bed fusion (LPBF) technique provides great potential for fabricating such composites with tailored structures and properties. However, porosity and cracking frequently arise during LPBF due to complex multi-field interactions, thus degrading their service performance. This review systematically summarized advances in LPBF-fabricated ceramic-reinforced superalloys. The key coupling relationships between ceramic particle characteristics, LPBF process parameters, and high-temperature service performance are systematically clarified. The metallurgical process, microstructure evolution, and precipitation behavior of superalloy composites are comprehensively scrutinized. The initiation and propagation mechanisms of metallurgical defects in these composites are explicitly analyzed and elucidated. Furthermore, the mechanical properties of the composite materials and their underlying strengthening mechanisms are thoroughly addressed. Finally, the bottleneck problems associated with ceramic-reinforced superalloy composites fabricated by LPBF are synthesized, and future perspectives are proposed.

Directionally solidified B4C-TiB2 eutectic ceramics are fabricated via optical floating zone (OFZ) method. Their microstructures and mechanical properties were analyzed by means of high-throughput characterization and image recognition analysis technology. The results show five different typical morphologies of eutectics. Quantitatively analysis based on high-throughput characterization results revealed that the width, length, length/width (L/W) ratio, area fraction of the TiB2 second phase were inhomogenously distributed along the specimen. Three-dimensional reconstruction visualized the spatial structure of eutectics, indicating a lamellar-rod transition that many be attributed to the amplified varicose instability of lamellar eutectic; rod-like eutectic is also observed adjacent to the coarse B4C phase within colony structure. Vickers hardness tested by indentation array exhibited a bimodal distribution with an average value of approximately 47.8GPa. Indentation size was comparable to the eutectic phase, with higher hardness observed in B4C lamellae especially near the TiB2 lamellar tip and lower hardness in TiB2 lamellae.

The elevated pouring temperatures characteristic of nickel-based superalloys usually result in a diminished efficacy of intermetallic grain refiners in their refinement capabilities. The Thermally Controlled Solidification (TCS) technique employs an extremely low pouring temperature, thereby enabling the practical utilization of such refiners. This study elucidates the grain refinement mechanism of CrFeNb and Co3FeNb2 intermetallic refiners in the IN939 superalloy under TCS conditions. After the addition of refiners, the average grain size markedly decreased from 6981 μm to 129 μm. The in-situ formation of the C14 Laves phase on refiner particles serves as the primary heterogeneous nucleation site. A specific crystallographic orientation relationship (OR) between the C14 Laves phase and the γ matrix was identified through Kikuchi patterns and electron backscatter diffraction (EBSD) analysis: [101]γ // [101̅0]Laves, (1̅11)γ // (2̅112)Laves. Edge-to-Edge Matching (E2EM) calculations corroborate the superior nucleation capability of the C14 Laves phase. Moreover, the refiners possess high stability and effectively homogenize the microstructure of complex castings. This study introduces a refinement mechanism for intermetallic refiners and offers theoretical insights to inform the development and application of innovative grain refiners for nickel-based superalloys.

Alumina-based eutectic composite ceramics have become important candidate materials for high-temperature structural applications in high-performance aerospace engines due to their outstanding property stability, high-temperature strength, excellent oxidation resistance, and corrosion resistance. In this study, large-sized Al2O3/GAP/ZrO2 eutectic ceramics with high aspect ratio and high width-to-diameter ratio were directly fabricated using laser directed energy deposition (LDED) technology with an optimized double-track overlapping scanning strategy free of sintering. The as-fabricated samples had diameters of 8-9 mm, heights of up to 135 mm, and relative densities higher than 98.5%. Under the double-track overlapping strategy, the crack density decreased progressively as the scanning speed increased from 200 to 360 mm/min, reaching a minimum value of 0.41 mm-1 at 360 mm/min. The eutectic spacing in the colony decreased from 0.47 +/- 0.07 to 0.15 +/- 0.02 mu m, and the irregular Chinese script eutectic structure within the colony gradually transformed into rod-like and lamellar structures. Due to the influence of local laser remelting, the cross-section of the eutectic ceramics exhibited an annular microstructure, while the longitudinal section displayed a periodically convex banded structure. At a laser power of 450 W and a scanning speed of 270 mm/min, the maximum fracture toughness of 6.35 MPa m1/2 was achieved. The optimized scanning strategy provides a new approach for the fabrication of large-sized oxide eutectic ceramics which is expected to overcome the bottleneck in manufacturing high-quality, large-sized, and complex-shaped ultra-high-temperature oxide ceramics. (c) 2026 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

High Jc Nb3Sn superconducting wires is mainly used in the preparation of high field magnets because of its higher critical current density. Further improving the critical current density of Nb3Sn wire, reducing the use amount of wire in magnets is one of important ways to promote the industrialization and mass application of High Jc Nb3Sn wire. It is known that doping Ti in Nb3Sn phase can improve the critical magnetic field effectively, refine the Nb3Sn grains, and improve the critical current density. Too much or too little Ti will greatly reduce the doping effect. The Ti diffusion is later than the Nb3Sn phase reaction under three-zone section heat treatment, so the distribution of Ti in Nb3Sn phase is uneven. This paper introduces a new heat treatment process, which can improve the uniformity of Ti in Nb3Sn phase by adding an insulation platform between the medium temperature and high temperature insulation platform. Eventually, the critical current density of the High Jc Nb3Sn wire was improved, reaching 2938 A/mm2.

The effects of laser-directed energy deposition (LDED) and casting on the microstructure evolution of an Al-10Ce alloy were studied. The results showed that the high cooling rate and the strong temperature gradient of the LDED inhibited the formation of the primary Al11Ce3 phase and promoted the refinement of the eutectic Al11Ce3 phase. At 300 degrees C, the LDED sample still exhibited excellent mechanical properties with the tensile strength, the yield strength and the elongation of 103 MPa, 79 MPa and 29.1%, which were better than those of the cast sample of 75 MPa, 46 MPa and 24.6%, respectively. Further, the high-temperature strengthening-toughening mechanism of the Al-10Ce alloy produced by LDED were mainly attributed to: (1) The refinement of the Al11Ce3 phase was conducive to the formation of high-density dislocations during deformation; (2) The elimination of the primary phase and the passivation of the phase interface reduced the stress concentration; (3) At high temperature, the dislocation recovery and the decomposition into stacking faults coexisted, which promoted the plasticity improvement and the strength maintenance.

High-temperature resistant ceramic matrix composites (HT-CMCs) have demonstrated immense application potential in aerospace，energy，and other extreme service environments，thanks to their outstanding attributes such as exceptional high-temperature resistance，high strength，low density，and excellent chemical stability. Traditional manufacturing processes are constrained in fabricating HT-CMCs with complex shapes and high performance. In contrast，additive manufacturing (AM) technology has paved a new way for the production of HT-CMCs with intricate structures，leveraging its unique capability of layer-by-layer construction. This technology substantially improves the functional properties and structural efficiency of materials by enabling the direct fabrication of complex internal features，like cooling channels. It also supports performance-oriented precise control and customized production according to specific service requirements，while significantly reducing material waste and effectively cutting down manufacturing costs. This paper focuses on the additive manufacturing technology of HT-CMCs. It introduces the technical principles and current application status of this technology，and places particular emphasis on expounding the latest research advancements both domestically and internationally in material system design，forming technologies，and process optimization for additively manufactured HT-CMCs. Furthermore，this paper sets out the future trends of additive manufacturing for HT-CMCs. In terms of material-process synergy，the focus is on overcoming the bottleneck of interface bonding in multi-material printing and developing composite processes to achieve multi-functional integration and gradient structures. Regarding the construction of intelligent systems，the aim is to establish a “digital control-real-time monitoring-parameter optimization” system and reduce trial-and-error costs through AI-based parameter adjustment. In the realm of modularization and circular manufacturing，the emphasis is on developing interchangeable standardized modules and innovating ceramic waste recycling technologies to enhance material utilization rates. All these endeavors are aimed at promoting its engineering application in cutting-edge fields.

This study resolved the long-standing trade-off between densification and microstructural coarsening in large oxide eutectic ceramics by fabricating bulk Al2 O3 /YAG/ZrO2 ceramics (120 mm x 10 mm) with an ultra-high density (99.83 %) and retained submicron eutectic structure (spacing 0.408 mu m). This achievement was enabled by an integrated innovative approach combining ultrafine micro-nano powders synthesized via laser floating zone melting at 300 mu m/s (spacing 0.141 mu m), ultrasonic wet sieving for interfacial purification, and low-temperature hot-pressing sintering at 1550 degrees C (150 degrees C below conventional temperatures), full densification within 45 min under 60 MPa pressure is enabled through a plasticity-dominated mechanism synergistically assisted by short-range interfacial diffusion. This plasticity-driven process, activated at 1200-1550 degrees C yielded ultrathin reconnected interfaces (0.7 mu m thickness) while avoiding grain coarsening. The sintered ceramics exhibited exceptional properties: Vickers hardness 16.25 f 0.46 GPa, fracture toughness 4.57 f 0.81 MPa m1/2 , and flexural strength 516.3 f 34.6 MPa at room temperature, significantly surpassing conventional sintered eutectic counterparts. High-temperature strength was retained at 290.1 f 33.6 MPa at 1200 degrees C through suppressed lattice expansion and micro-nano plasticity. Remarkably, after 500 h exposure at 1400 degrees C, constrained microstructural coarsening (eutectic spacing evolved from 0.408 to 1.097 mu m; Al2 O3 /ZrO2 /YAG phases limited to 0.651/0.406/0.434 mu m) resulted in enhanced hardness (16.74 f 0.37 GPa) and serviceable fracture toughness (3.09 f 0.17 MPa m1/2 ), demonstrating superior thermal stability via interface pinning effects. This work establishes a scalable plasticityenabled low-temperature sintering strategy for manufacturing large-sized structural components with high performance in extreme environments. (c) 2025 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

Co-Al-W-based alloys have been recognized as promising next-generation structural materials for high-temperature applications due to the formation of the γ′ strengthened phase. However, optimizing these superalloys through experimental studies is a significant challenge because of complex element interactions. This paper investigates the temporal processing and mechanisms of γ′ precipitates in novel Co-based superalloys using the phase-field method. By coupling the calculation of phase diagrams (CALPHAD) approach for the phase free energy and chemical mobility involving element interactions, and by calculating thermophysical parameters of alloys using first-principles, we developed a quantitative phase-field model for multicomponent systems. Using this model, the element diffusion path and γ′ evolution path are simulated in ternary diffusion couples and aging alloys, and the results align well with experimental observations. Furthermore, the effects of W content in Co-Al-W alloys on the coarsening kinetics and mechanisms of γ′ precipitates during long-term aging are systematically studied. It is found that increasing W content results in higher γ′ volume fraction and increased γ′ coarsening rate. The accelerated coarsening is primarily attributed to the shortened inter-particle spacing between γ′ precipitates, which is comprehensively analyzed through element diffusion distance and flux. Additionally, the model is extended to quaternary systems and successfully applied to Co-Ni-Al-W alloy. This study provides a novel method for the quantitative prediction of γ/γ′ microstructures and contributes to the alloy design and processing optimization of novel superalloys.

As perovskite solar cell efficiencies approach theoretical limits, the design focus for next-generation charge transport materials has shifted from single-property optimization to multifunctional integration. This present study aims to synergistically address both non-radiative losses caused by bulk defects and environmental risks stemming from lead ion leakage. A non-toxic xylitol additive is proposed, and the chelating site of five hydroxyl groups endows xylitol with excellent depolymerization function and also inhibits lead leakage in perovskite layers. After xylitol optimization, the champion efficiency of PSCs fabricated on SnO2 electron transport layers reach 21.7%. The PSC devices retain 92% of their initial PCE after 30 days in a nitrogen atmosphere. In contrast, SnO2-based PSCs retain only 72% of their initial PCE. Furthermore, it is found that the lead-suppressed ETL on one side of the perovskite layer has a lead suppression capability of approximately 60%. More importantly, the functional integrity of the perovskite layer remains unaffected by the lead suppression effect of the ETL. Overall, the incorporation of xylitol significantly enhances the overall performance of PSC devices, thereby providing a promising way to address the advancement of high-efficiency, stable, and environmentally benign PSCs.

Different annealing heat treatment processes were performed on Ni-Si hypereutectic composites at the solidification rate of 40 µm/s to eliminate the metastable phase and the best heat treatment process was selected (annealing temperature 1 000 °C, holding time 4 h). The oxidation weight gain and oxide rate, oxide film morphology, and oxidation kinetics of Ni-Si hypereutectic composites were studied. Moreover, the formation mechanism of the oxide film was investigated through a thermodynamic analysis, specifically by calculating the change of Gibbs free energy associated with the oxidation reactions. It is found that the oxide resistance of the Ni-Si hypereutectic composite without metastable phase is better than that of the 67.9

Arc-directed energy deposition (Arc-DED) is a promising additive manufacturing technology for fabricating medium-to-large-scale and lightweight structural components. The development of high-strength aluminum alloys is crucial for optimising the performance of these Arc-DED-manufactured components. However, achieving a high tensile strength remains a major challenge for Arc-DED fabricated aluminum alloys. In this work, high-Zn-content Al-Zn-Mg-Cu alloys were fabricated by Arc-DED, with a small amount of TiC and Al3Ti introduced for grain refinement. In-situ Zn alloying elevates the Zn content to above 9 wt.%, which plays a dominant role in achieving the ultra-high strength. This in-situ alloying is realised by pre-placing Zn foils on the top surface of each deposited layer. The combined interlayer remelting and mechanical hammering process promotes Zn homogenisation and improves the deposition quality. After T6 treatment, the high Zn content promotes the formation of fine, uniform and high-density nanoprecipitates, resulting in an ultra-high strength of 626 MPa.

Ceramic materials， with their high strength， high hardness， excellent high-temperature resistance， and superior corrosion resistance， have broad application prospects in fields such as machinery， electronics， aerospace， and biomedical engineering. However， traditional ceramic processing techniques are restricted by mold dependency and limited design freedom， making it difficult to meet the demand for efficient and rapid manufacturing of complex components. Laser additive manufacturing （LAM）， including laser powder bed fusion （LPBF） and laser directed energy deposition （LDED）， primarily achieves three-dimensional solid formation through layer-by-layer laser melting and stacking， providing a revolutionary solution for the rapid， customized manufacturing of complex-shaped ceramic components. However， the crack defects generated during the rapid solidification process in LAM severely constrain performance enhancement and engineering applications， becoming an urgent challenge and research hotspot in this field. This paper outlines the forming principles and the latest domestic and international progress of ceramic materials using LPBF and LDED technologies. It focuses on discussing the crack formation mechanisms， microstructural evolution， mechanical properties， and their influencing factors in direct laser additive manufacturing of ceramics. Additionally， it systematically summarizes strategies for suppressing cracks， such as forming preheating， process optimization， ultrasonic assistance， and microstructural control， along with their effects. Finally， it provides an outlook on the future development trends and core challenges of ceramic LAM technology， focusing on directions such as multi-physical field coupling simulations， material composition optimization， and multi-field assisted technologies， offering guidance for promoting the rapid development of ceramic laser additive manufacturing technology.

Since the misoriented grains in directional solidification blades can significantly degrade their mechanical properties, the anisotropy of DZ411 nickel-based superalloy during tensile testing along the solidification direction at 650 degrees C was investigated. The experimental samples were directly extracted from gas turbine blades. In single crystals (SX), as the orientation deviation angle increases from 2 degrees to 14 degrees, the yield strength decreases from 996 to 871 MPa. The yield strength of bi-crystal (BX) exhibits greater sensitivity to the orientation deviation angle. For the BX sample with deviation angles of 5 degrees and 7 degrees (5,7), the yield strength is 987 MPa. However, when the orientation deviation angles increase to (4,16), (24,32), and (20,28), the yield strength declines to 708, 701, and 688 MPa, respectively. Electron backscatter diffraction results reveal that orientation rotation is dominated by the {111} ( 110 ) slip system during tensile deformation, and the rotation direction of the grains can be influenced by adjacent grains. Additionally, grain boundaries (GB) constrain orientation rotation, as the strength at the GB exceeds that within the grain, causing the slip bands to stop moving near the GB. At the same horizontal position, the farther from the GB, the greater the orientation change. The primary reason for the elongation degradation in BX is the difficulty in coordinating the rotation directions during deformation due to the orientation differences between the two crystals. (c) 2026 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

The effect of 3 wt% Ru addition on the recrystallization behavior of a Ni-based single crystal superalloy was systematically investigated. The results revealed that Ru addition significantly promoted the microsegregation of Al and Ta elements into the interdendritic region during solidification, leading to an increased volume fraction of gamma/gamma ' eutectic from 6.67% in the Ru-free alloy to 9.5% in the 3Ru alloy. These enlarged eutectic regions, which exhibited lower deformation resistance than the dendrite cores, acted as preferential sites for strain concentration during indentation deformation, resulting in a larger deformation zone with higher dislocation density beneath the indentation in the 3Ru alloy. Upon subsequent heat treatment at 1315 degrees C, the recrystallization preferentially nucleated within these highly deformed gamma/gamma ' eutectic areas via the particle stimulated nucleation (PSN) mechanism. Consequently, the alloy with 3 wt% Ru additions exhibited a larger recrystallized area and coarser recrystallized grains compared to the Ru-free alloy. This work demonstrated that Ru addition promoted PSNmediated recrystallization nucleation by increasing the gamma/gamma ' eutectic content at as-cast and enhancing deformation localization.