Digital light processing (DLP) technology has attracted significant attention for its ability to quickly form complex structure porous silicon nitride (Si3N4) ceramics without the need for molds. However, challenges still exist regarding the rheological properties, stability, and curing performance of the Si3N4 ceramic slurry. This paper successfully enhances the rheology and curing performance of Si3N4 slurries by optimizing the multi-component photosensitive resin, dispersant system, and photocuring forming parameters. The results show that the multi-component resin system consisting of HDDA, TMP3EOTA, and ACMO at 3 & ratio;1 & ratio;2 mass ratio achieves optimal performance. Compared to the system containing IBOA, ACMO has no strong conjugated groups, and its morpholine ring can stabilize the free radicals of photoinitiators, achieving 95% increase in curing depth of the Si3N4 slurry. After the introduction of the dispersant Solsperse 41000, the stability and rheological properties of the slurry are further improved. As the content of Solsperse 41000 increases, the viscosity of the Si3N4 slurry first decreases and then increases; when the dispersant content reaches 3% of the powder mass, the slurry viscosity drops to its minimum value (0.16 Pa & centerdot;s). However, the addition of an excessive amount of dispersant will lead to multi-layer adsorption on the powder surface and self-entanglement of the dispersant itself, which impairs the rheological properties of the slurry. Based on the above optimizations, adjusting the laser power and exposure time to 15 mW/cm(2) and 7 s, respectively, can simultaneously meet the requirements for both curing depth and forming precision. Finally, Si3N4 ceramic green bodies with complex structures are successfully printed, and a porous Si3N4 ceramic with porosity of 18.76% and flexural strength of 240.28 MPa is ultimately produced. This study provides an experimental basis for the preparation of highperformance porous Si(3)N(4 )ceramics.

This research presents a new design method for lightweight, energy-absorbing, hybrid lattice structures of triply periodic minimal surfaces. Traditional diamond (D) and gyroid (G) lattices are hybridized with varying weights to create a novel structure that combines their advantages. An Al-Cu-Mg-Y alloy fabricated via laser powder bed fusion with ultrahigh compressive ductility is used to prepare the lattices. Results show that the D6G4 lattice (60 wt.

Additive manufacturing offers a transformative approach to fabricating ceramics for water treatment through precise multi-scale structural control. This paper comprehensively reviews the application advancements of stereolithography and extrusion-based additive manufacturing techniques for fabricating water treatment ceramics in oil-water separation， organic pollutant degradation， and seawater desalination scenarios. However， persistent challenges involve resolution limitations below 100 nm constraining precise separation layers， trade-offs between structural complexity and mechanical integrity causing delamination risks under pressure， and scalability barriers elevating costs. Future advancements will require self-healing smart ceramics enabling autonomous crack repair alongside machine learning-guided co-design strategies to optimize structure-function relationships. This review aims to provide a reference for the research on additive manufacturing of water treatment ceramics， to promote the industrial application of additive manufacturing technology in high-throughput and long-life water treatment ceramics.

Vat photopolymerization (VPP) technology holds significant potential for fabricating high-precision SiC components with complex structures. However, SiC, as a covalently bonded compound, exhibits low sintering activity, which greatly limits the densification process and its mechanical property. In this paper, a new bimodal particle size SiC combined with reactive melt infiltration (RMI) for fabricating high-performance SiC is developed. Compared with uniform particle sizes, a rational graded particle size distribution contributes to altering the single failure mode and enhancing the mechanical properties of SiC. During RMI, the incorporation of appropriate fine particles reduces the aggregation of residual silicon within SiC matrix, which confines the reaction between pyrolytic carbon and molten silicon to localized regions. This facilitates concentrated growth of the reinforcing beta-SiC phase, serving as the key mechanism for performance improvement. The final SiC achieve a bulk density of 2.996 g/cm3 and a maximum flexural strength of 369.67 MPa, which reflecting an approximate 83 % improvement in strength. This method offers an effective solution for fabricating high-strength SiC with complex structures using VPP technology.

The NiTi lattice structure has great application potential in biomedical and aerospace fields, due to the shape memory effect, hyperelasticity and other characteristics. According to the research purpose and material behavior, cyclic compression is divided into hyperelastic cyclic compression and fatigue cyclic compression. Many studies have been conducted, but either to improve the hyperelastic cyclic compression performance or to improve the fatigue cyclic compression performance, no study has yet revealed the connection between the two. Therefore, in this study, hyperelastic cycles (1, 8, 15) were conducted before fatigue cyclic compression, while fatigue cycles (104, 5 & times; 104, 105) were conducted before hyperelastic cyclic compression. The results show that the fatigue cyclic compression pretreatment of 104 and 5 & times; 104 cycles helps to improve the hyperelasticity of the lattice structure, while too many fatigue cycles will reduce the hyperelasticity of the structure. Furthermore, the bearing capacity of the sample is enhanced by 104 cycles of fatigue cyclic compression pretreatment. On the contrary, the fatigue life of the sample can be increased by 2.49 times after 8 cycles of hyperelastic cyclic compression pretreatment, due to reducing the grain size. This study reveals the interaction mechanism between hyperelasticity and fatigue performances of NiTi lattice structures.

Aiming at the problem that the internal short carbon fiber （Csf） of carbon fiber reinforced silicon carbide （Csf/SiC） composites prepared by laser powder bed molten/liquid silicon permeation （LPBF/LSI） is prone to be eroded by molten Si， which limits the strengthening and toughening effect of fibers on the matrix and restricts the performance improvement of Csf/SiC composites formed by LPBF/LSI. This study propose to coat pyrolytic carbon （PyC） and silicon carbide （SiC） coatings respectively on the surface of Csf by hydrothermal carbonization and dip coating-pyrolysis processes， and Csf/SiC composites are prepared through LPBF/LSI. The influence of the fiber surface coating on the microstructure and mechanical properties of Csf/SiC composites is studied. The results show that the SiC coating can prevent the direct contact between Csf and molten Si， avoid the dissolution-precipitation reaction at the interface between the two， and thereby protect Csf. Compared with the Csf/SiC composites with Csf and Csf@PyC， the internal fibers of the Csf/SiC composites with Csf@SiC still retained better original structure， while the Csf inside the former two showed reactive erosion. The fibers retained due to SiC coating protection improved the flexural strength and fracture toughness of Csf/SiC composites to a certain extent through crack deflection， coating de-bonding and fiber pulling mechanisms， which are 7.1% and 8.3% higher than those of Csf/SiC composites with Csf and Csf@PyC， respectively. The maximum reaches 246.09 MPa and 3.28 MPa·m1/2. In this study， the synergistic improvement of the strength and toughness of Csf/SiC composites is achieved through the optimization of fiber surface coatings， providing a certain theoretical basis for the preparation of high-performance Csf/SiC composites by LPBF/LSI.

In additive manufacturing of continuous Cf/SiC composites using resin-based fiber filaments, the resin acts as a binder in preforms and must be removed by debinding. Neglected defects after debinding, such as resin shrinkage and fiber aggregation, directly impact subsequent SiC matrix densification and properties of Cf/SiC composites. This study introduces a high-temperature treatment after debinding to solve the aforementioned problems and investigates the effect of 1200-1600 degrees C treatment on Cf filaments and Cf/SiC composites. For Cf filaments, hightemperature treatment enhances the damage resistance of SiC matrix densification but also weakens the Cf initial strength. Therefore, the Cf filaments after 1400 degrees C treatment exhibit the highest strength retention. For Cf/SiC composites, the Cf dispersion enhanced by high-temperature treatment was evaluated using the nearest-neighbor distance. Finite element analysis reveals that SiC matrix shrinkage generates 7.4 GPa compressive stress on the Cf. Dispersed fiber reduces stress concentration by 41.9 % and increases the composite density by 5.1 %. The flexural strength and fracture toughness of the corresponding composites reached 368.0 MPa and 11.9 MPa & sdot;mm1/2, representing increases of 77.5 % and 63.0 % compared with only debinding samples. Finally, the fabricated Cf/SiC parts demonstrated promising potential for application in large-scale and complex aerospace structures.

Additive manufacturing technologies have provided reliable solutions for the formation of complex silicon carbide (SiC) ceramic components, promoting their applications in cutting-edge technology fields, and therefore have received widespread attention. However, there is still a problem with mechanical properties in the additive manufacturing of SiC ceramics, which greatly limits its application. In this paper, robotic arm-assisted additive manufacturing technology for continuous fiber toughened SiC ceramic matrix composites is first introduced. A two-step infiltration and pyrolysis method is proposed to prepare continuous SiC fiber toughened SiC (SiCf/SiC) ceramic matrix composites with high performance after using thermoplastic resin to form the green body. The first step is to remove the resin from the green body and maintain the shape of the sample. The second step is the cyclic precursor infiltration and pyrolysis (PIP) at different temperatures, which densifies the SiCf/SiC ceramic matrix composites. When the temperature of the PIP process is 1000 degrees C, the SiCf/SiC composites get high performance with flexural strength and fracture toughness reaching 425.03 +/- 10.71 MPa and 20.52 +/- 2.21 MPa center dot m1/ 2 respectively. This study provides a novel additive manufacturing method for continuous fiber toughened ceramic matrix composites.

NiTi shape memory alloys with lattice metamaterials architectures offer a promising route toward lightweight structures capable of reliable and recoverable deformation; however, the functional behavior of such lattice metamaterials in an ultralight regime remains largely unexplored. In this study, ultralight NiTi Gyroid lattice metamaterials with volume fractions ranging from 1% to 4% were designed and fabricated by laser powder bed fusion. By integrating Gyroid-specific design optimization, systematic process window identification, mechanical testing, and finite element analysis, the mechanical behavior, functional response, and deformation modes of these lattices were comprehensively investigated. The results demonstrate that, despite extreme geometric slenderness, ultralight NiTi Gyroid lattices can achieve near- complete functional recoverability, with a superelastic recoverable ratio of up to 93.65% and shape memory recovery exceeding 98.99% at an 8% compressive strain. Moreover, a volume-fraction-governed fracture-mode transition was revealed: ultralight Gyroid lattices exhibit a stable layer-by-layer collapse behavior, whereas denser Gyroid lattices transition to shear-dominated failure above a critical volume fraction of approximately 14%. Importantly, a mechanics-based semi-empirical criterion was established to quantify this critical volume fraction, enabling predictive design of fracture modes in Gyroid lattices. These findings establish a structure-enabled pathway for achieving stable functional performance and predictable deformation behavior in ultralight NiTi Gyroid lattices, providing design guidance for deformation-controlled lattice metamaterials under stringent weight constraints.

Difficult-to-machine metals typically possess unique physical and mechanical properties,such as high-temperature stability,high specific stiffness,and lightweight characteristics.These metals hold strategic significance for high-end equipment sectors such as aerospace,energy and power,and marine engineering.This study systematically reviews the research progress and development trends in the integrated additive manufacturing/hot isostatic pressing(AM/HIP)forming technology for difficult-to-machine metals.The study focuses on the following four typical materials:(i)Be and its alloys,(ii)Ti2AlNb alloys,(iii)nickel-based superalloys with high Ti/Al content,and(iv)metal matrix composites.This study provides an in-depth analysis of the bottlenecks encountered in conventional processing,such as high forming difficulty,low material utilization,and poor microstructural homogeneity.Furthermore,the study highlights key research breakthroughs in the integrated AM/HIP technology,including multiscale HIP sim-ulation,compensation design methods for capsule structures,AM of high-precision and high-density thin-walled capsules,and AM of high-strength soluble ceramic cores.A comparative analysis is performed on the advantages of the technology in the near-net shaping,microstructural homogenization,and perfor-mance optimization of components made from difficult-to-machine materials.Finally,future developments for the technology are outlined,including scientific capsule design,intelligent process control for capsule AM,and synergistic optimization of ceramic core properties.This study provides theoretical support and practical pathways to promote the innovative development of HIP forming technology,expanding its appli-cation in the near-final forming of complex components made from difficult-to-machine metals,and offer-ing technical assistance for the manufacturing of core components in key sectors in China,such as aero-space and defense equipment.

Laser powder bed fusion (LPBF) fabricated silicon carbide (SiC) has great potential for optical mirrors and semiconductor equipment because of its advantages in lightweight design and complex geometry fabrication. However, the resulting substrates still suffer from insufficient densification, limited purity, and poor surface quality. Dense SiC coatings are therefore usually deposited to form a functional surface layer, and the strong interfacial adhesion is essential for reliable service. To address this issue, this study innovatively proposes a surface patterning strategy for additively manufactured SiC substrates. Groove patterns were introduced onto the substrates, and the effects of groove width and spacing on coating adhesion strength, nanomechanical properties, crystallographic orientation, and interfacial fracture behavior were systematically investigated. The results show that decreasing groove width improves both coating adhesion strength and nanomechanical properties, while adhesion strength first increases and then decreases with increasing spacing. The sample with a groove width of 0.4 mm and a spacing of 1.5 mm achieved the highest adhesion strength of 20.7 MPa, which is 4.3 times that of the non-patterned substrate. Its nanomechanical properties were also significantly improved. The groove patterns favored V-shaped coating growth with preferred (111) orientation, whereas the patterned interface induced crack deflection during fracture. These combined effects contributed to the enhanced interfacial adhesion. This study provides a practical and effective strategy for improving coating adhesion in high performance SiC components.

Directed energy deposition (DED) is an effective method for lunar highland in-situ construction, while the processing mechanism of gabbroic regolith simulants is not clear, which is the key to improving the mechanical properties. Therefore, this study systematically investigates the microstructural evolution of lunar highland gabbroic regolith simulants after DED processing and analyzes the performance enhancement mechanism. After DED processing, the silicate network structure undergoes a transition from low polymerization to high polymerization, wherein the chain-like structures of augite and amphibole in the raw powder evolve into a more highly polymerized and stable framework silicate structure. During the DED process, the minerals such as amphibole undergo de-hydroxylation reactions, undergoing a 3.43% weight loss and releasing H2O. The DEDprocessed sample exhibits the compressive strength reaching 5.32 MPa. After heat treatment, the amorphous glassy phase in the DED process is transformed into crystalline mineral phases such as enstatite, olivine, and plagioclase with precipitating columnar, acicular, and lamellar crystals. The compressive strength can reach 47.56 MPa, which is nearly 24 times higher than that of the DED-processed samples at the same energy density. This study provides theoretical guidance and technical support for future lunar highland construction.

Titanium alloy has been regarded as one of the most demandable and potential materials in the additive manufacturing (AM) community due to its good printability and extensive applications. While the durability and ductility of the as-built titanium alloy specimens were markedly lower than the forgings due to the rough surfaces, acicular martensite structure and high stress state. Here, heat treatment and surface treatment (i.e., shot blasting and machining) were performed on the laser powder bed fused (LPBF) Ti-6Al-4V specimens and forging counterparts to investigate the effects of surface roughness and microstructure on the tensile and fatigue properties. The results indicated that the tensile and fatigue strength were greatly improved after surface treatment, and fatigue limits was further improved after heat treatment. The optimized combination of heat treatment and surface processing provides reliable strategy guidance for the mechanical property improvement of LPBF-produced Ti-6Al-4V alloy.

Vat photopolymerization (VPP) has recently been applied to fabricate silicon nitride (Si3N4) ceramics. To overcome limitations in Si3N4 slurry curing performance, a multi-functional modification strategy utilizing the metal-organic framework MIL-53(Al) was proposed. The introduction of MIL-53(Al) simultaneously affects slurry photocuring performance and ceramic microstructural regulation. MIL-53(Al) serves as a fluorescent active filler acting as an in situ photon source under ultraviolet irradiation, thereby enhancing the curing depth by an average of 17.5 & micro;m. During the debinding process, the decomposition of MIL-53(Al) leaves a pore structure and aluminum oxide that can assist sintering, facilitating phase transformation and forming a well-interlocked beta-Si3N4 microstructure. The sintered Si3N4 ceramic exhibited a flexural strength of 269.2 +/- 12.6 MPa, and a fracture toughness of 3.54 +/- 0.21 MPa & centerdot;m1/2 at a porosity of 23.9%. This study demonstrates the multi-functional role of MOF-based additives for both enhancing slurry printability and tailoring ceramic microstructure in fabrication of porous Si3N4 ceramics via VPP.

Continuous silicon carbide fiber-reinforced silicon carbide (SiCf/SiC) composites with lightweight, high-strength, excellent high-temperature and oxidation resistance have received increasing attention in aerospace, nuclear energy, and transportation engineering. However, it is difficult for current processing techniques to form SiCf/SiC composites with complex shapes, and their mechanical properties are limited. In this study, we report the fabrication of SiCf/SiC composites via robot-assisted 3D printing technology and the innovative introduction of biomimetic crossed-lamellar structures with varied summit angles to improve their mechanical properties. The effect of the summit angles on the forming quality and mechanical properties of the SiCf/SiC composites was investigated, and the toughening mechanism of the crossed-lamellar structure was analyzed. Results reveal that robot-assisted 3D printing technology can achieve excellent printing quality at different summit angles, and the multi-orientation fiber alignment in crossed-lamellar structure promotes synergistic toughening through intralayer and interlayer crack propagation. When the summit angle is 120 degrees, the SiCf/SiC composite exhibits significant reinforcement, achieving ultra-high flexural strength and fracture toughness of 307.38 +/- 7.9 MPa and 20.74 +/- 1.05 MPa & sdot;m1/2, respectively, especially the fracture toughness is increased by 72 % compared to the unidirectional structure. This work provides a novel approach for the fabrication of high mechanical performance continuous fiber-reinforced ceramic composites.

SiC ceramic matrix composites (SiC CMCs), with their low density, high specific strength, high wear resistance, and high thermal stability, have demonstrated significant application potential and importance in critical fields such as aerospace, nuclear technology, and the automotive industry. However, traditional forming processes often rely on molds and face challenges such as lengthy production cycles, high manufacturing costs, and difficulties in producing complex components. In this context, additive manufacturing (AM), a cutting-edge digital manufacturing technology that integrates the core principles of mechanical engineering, computer science, CNC technology, and materials science, has brought revolutionary changes to the production of SiC CMC components. This technology eliminates the constraints of traditional molds by employing an advanced principle of layer-by-layer construction and stacking, enabling a direct transition from design to finished product. Theoretically, it can precisely form any complex geometric shape, significantly expanding the design freedom and structural complexity of SiC ceramic components. This paper provides an overview of the latest developments in AM research on Cf/SiC CMCs, SiCf/SiC CMCs, SiC/metal CMCs, and other types of SiC CMCs, and offers insights into the future direction of the field. It is hoped that this review will provide new perspectives and inspiration for relevant researchers, thereby promoting the progress and development of the field.

Over the past few decades, considerable research attentions have been dedicated to fabricating defect-free and complex-shaped composite ceramic parts via vat photopolymerization (VPP) technology through the introduction of plasticizers into photocurable ceramic suspensions. Despite these efforts, the fabrication of highperformance composite ceramics remains unsatisfactory, primarily due to low defect restraining efficiency and severe serious negative effects on other critical properties, such as increased suspension viscosity, poor printing accuracy, and heterogeneous and coarsened grain, after the addition of plasticizers. Herein, we present a novel multifunctional plasticizer dimethyl adipate (DMA), to fabricate high-performance zirconia-toughened alumina (ZTA) ceramics via VPP additive manufacturing (AM). Through the incorporation of DMA, the resulting 55 vol% photocurable Al2O3/ZrO2 suspension demonstrated outstanding rheological, spreading, and photocuring behavior, resulting in a low viscosity, excellent spreading behavior, and the lowest excessive curing width. The obtained Al2O3/ZrO2 green-body exhibited excellent mechanical and thermomechanical properties, along with a mild binder removal process. Finally, the resultant 3D-printed ZTA ceramics simultaneously exhibited near-full densification (99.5 %), superior surface quality, homogenous and fine grain distribution, the lowest degree of defect generation (0.01 %), and better mechanical properties (663.3 MPa, 7.4 MPa center dot m1/2). The significant improvement in material properties can be attributed to the carefully engineered inorganic/organic colloidal suspension network and semi-interpenetrating (s-IPN) network microstructure. These structures facilitate effective adsorption of DMA molecules onto ceramic particle surfaces, impart a moderate plasticizing effect, and establish a plasticizer/acrylic resin interface characterized by optimal compatibility and bonding. The present study proposes universal strategies for achieving comprehensive performance enhancement in VPP-fabricated composite ceramics.

Laser powder bed fusion (LPBF) enables the fabrication of metallic components with complex geometries directly from raw powders. The process typically employs continuous-or pulsed-wave lasers, which significantly impact the thermal-fluid dynamics and subsequently affect the microstructure. However, the behaviour during pulsed-wave LPBF remains inadequately understood. This study developed a highfidelity multi-physics modelling framework to simulate the evolution of point-by-point laser exposure during pulsed-wave LPBF. The effects of laser power and exposure time on thermal-fluid behaviour in single-/multi-track and multi-layer pulsed-wave LPBF were investigated and validated against experiments. The results reveal that variations in either laser power or exposure time can result in similar molten pool morphology during a single exposure, though their dynamic behaviours exhibited marked differences. Increased laser power augmented the drilling rate of the molten pool, while exposure time exhibited a minimal effect on the depth growth rate, thereby enhancing the predictability of its behaviour. Additionally, the critical molten pool depth at which the drilling rate changes remained nearly constant, irrespective of laser power or exposure time. During point-by-point scanning of a single melt track, gaps formed between exposures due to mismatches in laser power, exposure time and point distance, resulting in track discontinuities. In subsequent scanning, deep gaps arose from poor bonding within intra-tracks and insufficient melting between inter-tracks and inter-layers. Keyhole pores primarily formed during the laser-off period of the pulse cycle at high laser powers or exposure times, as surface tension and gravity drove molten material forward, but solidification pinned the keyhole tip, leading to defects. These findings significantly advance the understanding of melt pool dynamics and defect formation in pulsed-wave LPBF. (c) 2025 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.