High-entropy alloys (HEAs) exhibit unique mechanical properties, including high hardness, exceptional thermal stability, and good corrosion resistance, making them promising candidates for wear-resistant applications. However, systematic investigations of their tribological behavior at the atomic scale remain limited. In particular, the influence of Ti content on the friction and wear mechanisms of FeNiCrCoTi-based HEAs is still not well understood. This study investigates the effects of titanium content (0-20%) and indentation depth (8-14 & Aring;) on the tribological behavior and deformation mechanism of FeNiCrCoTiX high-entropy alloys using Molecular dynamics (MD) simulation. The findings show that the coefficient of friction for T10 (20% Ti) is 0.67 higher than that for T0 (0% Ti), and that both the number of wear atoms and the wear rate increase with Ti content. This is because increasing Ti content intensifies lattice distortion because of atomic size mismatch, which decreases the FCC phase while promoting the formation of BCC and other phases. This microstructural transformation lowers the total plastic deformability of the material. Additionally, the coefficient of friction reaches a maximum of 1.661 at an indentation depth of 14 & Aring;. As the indentation depth increases, the depth of the deformed region increases by 18 & Aring; and its width by 13 & Aring;. This is because deeper indentation depth enlarges the contact area between the abrasive and the alloy, inducing more severe subsurface lattice damage, which considerably increases the lateral friction force. Finally, with increasing sliding distance, the accumulated plastic deformation from sustained shearing and the number of wear atoms both grow substantially. This study aims to elucidate the tribological properties and underlying mechanisms of FeNiCrCoTi alloys, providing insights that support their potential use in wear-resistant applications.

Digital light processing (DLP)-based fabrication offers a promising route to producing high-resolution Ti6Al4V components, but severe and anisotropic shrinkage during sintering remains a major challenge for dimensional accuracy, particularly in complex geometries. Accurate prediction is hindered by the high computational cost and numerical difficulty associated with constitutive parameter calibration in thermomechanically coupled sintering simulations. In this study, a prediction framework based on the Skorohod-Olevsky viscous sintering (SOVS) model is combined with a sampling-driven inverse calibration strategy using Progressive Latin Hypercube Sampling (PLHS) and a kinematic-volumetric constraint for constitutive parameter identification. The calibrated model is validated over a wide sintering temperature range and shows good agreement with experiments, with prediction errors below 3% for relative density and anisotropic shrinkage. For Schwarz P, Gyroid, and gear structures, geometry-dependent deformation is predicted with dimensional deviations below 4% from macro- to micro-scale features, while residual stress analysis reveals topology-dependent stress localisation in complex architectures. These results demonstrate that the proposed framework provides a practical approach for dimensional compensation and near-net-shape manufacturing of DLP-fabricated Ti6Al4V components.

Silicon nitride (Si3N4) ceramics are ideal for thermal management but often suffer from limited thermal conductivity due to oxygen impurities. In vat photopolymerization (VPP), pyrolytic carbon (PyC), a byproduct generated during the debinding process, is traditionally viewed as a harmful impurity. This study presents a pioneering "waste-to-wealth" strategy that repurposes in-situ PyC as an oxygen getter, unlocking its potential to enhance the thermal conductivity of Si3N4 ceramics. By adjusting these parameters, a maximum thermal conductivity of 92.18 W center dot m-1 center dot K-1 was achieved with decarbonization at 450 degrees C and presintering at 1350 degrees C. This represents a 17.29% enhancement compared to the baseline debound in air without presintering. This enhancement is attributed to the synergistic interplay of reduced oxygen content, a strategically isolated intergranular phase, and a carbon-modulated grain orientation that mitigates the detrimental effects of misaligned a/b-axis grain boundaries. Our findings demonstrate a new strategy to enable performance customization in additively manufactured ceramics.

Powder bed fusion (PBF) has emerged as a highly promising additive manufacturing technology for fabricating high-performance carbon fiber reinforced polyetheretherketone (CF/PEEK) composites. However, the underlying correlation between the inherent manufacturing process, microstructural evolution, and resultant macroscopic properties remains elusive. This study systematically elucidates the anisotropic tribological behavior of PBF-printed CF/PEEK composites driven by process-induced fiber orientation. Microstructural analysis reveals that the shear flow during the powder-spreading phase induces a preferential alignment of carbon fibers. Consequently, the X-Z plane exhibits a higher fiber cross-sectional area fraction (7.88%), where the vertically oriented fibers act as robust "load-bearing micro-pillars". This unique micro-architecture significantly resists plastic deformation and plowing, reducing the specific wear rate to 2.0 × 10⁻⁶ mm³/Nm—an order of magnitude lower than pure PEEK, and 28% lower than the perpendicular X-Y plane. To validate the structural superiority of this composite under extreme engineering conditions, gear meshing tests were conducted, demonstrating a 3.8-fold enhancement in wear resistance based on the mass loss proportion. These findings provide profound insights into tailoring the anisotropic architecture of polymer composites via PBF processing, offering a theoretical paradigm for designing advanced multifunctional components.

Solid oxide fuel cells (SOFCs) are highly efficient energy conversion devices with broad fuel flexibility. Concentration polarization has been identified as the dominant factor causing voltage loss under high-current conditions, and mesoscopic porous electrodes have shown promise in alleviating this issue. However, the techniques available for fabricating customized and intricate mesoscopic porous SOFC electrodes remain limited. Herein, we utilized vat photopolymerization 3D printing to fabricate SOFC anode supports with mesoscopic interconnected array of conical channels (IACC). This IACC structure effectively enhanced gas transport, leading to a significant reduction in concentration overpotential in the SOFC. A peak power density of 745 mW & sdot;cm-2 was achieved at 800 degrees C in an SOFC configured with a (La0.75Sr0.25)0.95MnO3 cathode, outperforming most existing studies. The novel, efficient, and controllable approach for optimizing mass transport within the electrodes, opens new avenues for developing high-performance SOFCs.

This study combines density functional theory (DFT) calculations with experimental analysis. The plane-averaged charge density difference at the interfaces was systematically evaluated, and the structural evolution and electronic property changes during different stages of tensile failure were thoroughly analyzed. The experimental characterization elucidated the strengthening mechanisms of WC particles on the matrix, elemental segregation behavior, and fracture micro-morphology. The calculation results indicate that a strong polar covalent bond exists between Fe and C, and the charge redistribution at the C-terminated interface has a more profound influence. For the three WC/γ-Fe interfaces, the theoretical critical strains are 1%, 13%, and 19%, corresponding to tensile strengths of 11.98 GPa, 34.66 GPa, and 37.53 GPa, respectively. Among these, the WC(0 0 0 1)/γ-Fe(1 1 1) interface with W-HCP configuration is the highest bonding strength. A higher interfacial tensile strength tends to shift the fracture location from the interface to the interior of the matrix. Experimentally, it was found that the introduction of WC provides heterogeneous nucleation sites for the melt pool, refining the matrix microstructure. The formed tungsten-rich carbides preferentially segregate along grain boundaries, effectively impeding dislocation motion, which constitutes the primary strengthening mechanism for the enhanced plasticity of the composite.

Digital light processing (DLP) additive manufacturing is employed in this work to fabricate in situ Ti6Al4V-TiC composites. Attention is given to slurry formulation and exposure optimization to ensure stable curing and reliable interlayer bonding. A Ti6Al4V slurry with optimized particle size and photoinitiator content enables stable curing with sufficient thickness of approximately 49 mu m and reduced light scattering at an exposure energy of 750 mJ/cm2, allowing precise fabrication of self-supporting complex structures. After debinding and sintering, the components exhibit smooth surfaces, low residual porosity, and a predominantly equiaxed alpha-Ti microstructure with in-situ formed TiC particles. The TiC phase originates from the reaction between the Ti matrix and residual carbon generated during resin pyrolysis, resulting in a Ti6Al4V-TiC composite. The fabricated composites demonstrate a high compressive strength of 2321.3 MPa and low residual stress. This research demonstrates the potential of DLP technology in preparing Ti6Al4V-TiC composites with complex structures and provides a new approach for metal composite additive manufacturing.

Residual carbon is a major obstacle in DLP processing of Ti6Al4V, but its controlled conversion into a reinforcing phase may provide a route to simultaneously address contamination and poor wear resistance. In this work, DLPfabricated Ti6Al4V alloys were sintered at 1150-1400 degrees C to tailor densification, microstructure evolution, and in situ TiC formation. The sample sintered at 1300 degrees C exhibited near-full densification, a refined grain size of 10-11 mu m, the highest nanohardness of 8.91 GPa, a low friction coefficient of 0.58, and a minimum wear rate of 4.12 & times; 10-5 mm3 center dot N-1 center dot m-1 . The enhanced tribological performance originates from the synergistic combination of strong TiC/Ti matrix interfacial bonding and a stable tribo-oxidative protective layer. By contrast, excessively high sintering temperatures lead to TiC and matrix coarsening, destabilize the tribo-layer, and promote three-body wear. This study demonstrates a practical strategy to convert residual carbon into in situ TiC reinforcement and establishes the processing-microstructure-tribology relationship in DLP-fabricated Ti6Al4V alloys.

Unlike prior studies that have exclusively focused on the best-matched Fe(111) surface, the present work quantitatively compares the bonding performance of three distinct gamma-Fe crystallographic planes with WC so as to minimize and even circumvent defects inherent in additively manufactured metal-matrix composites. By means of first-principles calculations performed with CASTEP, we systematically investigated the structural characteristics and properties of the interfaces formed between LPBF-fabricated 316 L stainless steel (gamma-Fe matrix) and WC reinforcement. Key quantities include the interfacial binding energy, charge density distribution and transfer, and the nature of interfacial bonding for the dominant heterostructures encountered in the composite. The results show that among the Fe(001), Fe(011), and Fe(111) terminations paired with WC(0001), the Fe(111) surface possesses the lowest surface energy and is therefore the most readily exposed and thermodynamically stable facet in the FCC binder phase. For WC acting as a strengthening phase, three stacking sequences and two possible termination planes give rise to six distinct Fe/WC interfaces. Among them, the interface formed between Fe(111) and WC(0001) exhibits the highest stability among all configurations. Specifically, the W-terminated interface in the HCP stacking mode exhibits the largest work of adhesion (Wad=13.42 J/m2), signifying that the reversible work required to separate this interface into two free surfaces is the greatest of all cases examined. Analysis of the electronic structure and density of states (DOS) reveals that interfacial cohesion originates primarily from metallic Fe-Fe bonds and covalent and ionic Fe-W/C interactions. Charge density and charge density difference maps further elucidate the atomic arrangement, electronic structure, stability, and electronic properties of the interface, allowing us to track electron gain and loss across the boundary. These insights enable an assessment of interfacial strength and a determination of whether the interface constitutes a weak link within the gamma-Fe matrix composite. The findings provide essential theoretical guidance for enhancing the interfacial strength and stability of WC-reinforced Fe-based composites produced by additive manufacturing.

Digital Light Processing (DLP) technology is expected to be widely applied in the additive manufacturing of metal materials with complex structural components due to its high resolution and efficiency. However, defects introduced during debinding limit the forming quality of the components. In this research, the non-reactive diluent polypropylene glycol (PPG) is added to Ti6Al4V (Ti64) alloy slurry, and their effects on the thermal decomposition behaviors of green parts are studied based on experimental investigations and numerical simulations. The results indicate that the PPG addition can promote the smooth decomposition of organic matter by constructing gas transmission passages in the early stages of debinding processes, which significantly reduces the temperature difference, residual content of organic matter, pore pressure, and maximum principal stress between the surface and center of the green part, thus reducing the crack defects in the final components. When the addition amount of PPG is 20wt%, the defect-free Ti64 components with complex structures and excellent mechanical properties can be efficiently fabricated. This research can provide references for the design of Ti64 photopolymerization slurry, further expanding the applications of DLP technology in the field of metal additive manufacturing.

In this study, 3 wt.% Re/Inconel 718 composite was fabricated by laser powder bed fusion (LPBF), and the effects of aging treatments on the microstructure and properties of the Re/Inconel 718 composite were systematically investigated. This study aims to elucidate the synergistic optimization of microstructure and properties in LPBF Inconel 718, achieved through Re alloying and subsequent heat treatment. Results demonstrated that the samples undergo recrystallization and precipitate numerous fine strengthening phases after heat treatment. Concurrently, heat treatment promotes the diffusion of Re within the material, leading to a significant reduction in its concentration in locally enriched regions. The addition of Re improves the mechanical properties and corrosion resistance of the Inconel 718 alloy through synergistic strengthening mechanisms, including dispersion strengthening, solid solution strengthening, and dislocation strengthening. When the two-stage aging is 720 °C × 8 h (FC × 2 h) + 620 °C × 8 h (AC), the optimum mechanical properties are observed. The dissolution of Laves phases, simultaneous precipitation of both γ″ and γ′ phases, and homogenization of microstructure are responsible for the enhancement of the material’s mechanical properties. However, the extensive precipitation of strengthening phases also promotes the formation of numerous microscopic corrosion cells, which accelerates the corrosion rate and leads to a marked reduction in corrosion resistance of the material. This study provides new insights into the laser additive manufacturing of high-performance nickel-based composites.

OBJECTIVES:To evaluate the feasibility of utilizing Digital Light Processing (DLP) 3D-printing technology to fabricate ultra-thin (0.1-0.7 mm) zirconia dental veneers. MATERIALS AND METHODS:A high-load (80 wt%) 3Y-zirconia slurry (5 Pa·s at a shear rate of 30 s-1) was used to print zirconia green bodies with a custom-made DLP 3D-printer (405 nm UV light and X/Y plane resolution of 70 μm). Flexural strengths of green bodies and fully sintered zirconia printed in two orientations (0º and 90º) were evaluated using three-point bending (3PB) and biaxial flexural strength (BFS) tests, respectively. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to examine the microstructure and crystalline phases of the sintered specimens. A commercial 3Y-zirconia (UPCERA MT) was used as a control for comparison with the best-performing DLP-printed specimens. XRD and SEM were used to assess low-temperature degradation (LTD) after artificial aging (autoclave, 5 hr). Transparency of the sintered DLP-printed and conventional zirconia at 0.5 mm and 1.0 mm thicknesses was measured using a desktop spectrophotometer (400-700 nm). Resin-zirconia bonding performance was evaluated via shear bond strength (SBS) testing and failure mode analysis. SBS was measured between a self-adhesive dual-curing resin cement and the surface of sintered zirconia specimens. The coefficient of thermal expansion (CTE) and Schwickerath three-point bending strength (τb) were measured to evaluate porcelain-zirconia compatibility. Ultra-thin (0.1-0.7 mm) dental restorations were fabricated to demonstrate the practical potential application of this novel zirconia printing approach. RESULTS:The 3PB flexural strength of green bodies printed at 0º (21.35 ± 2.19 MPa) was significantly higher (p < 0.05) than at 90º (16.98 ± 1.68 MPa). The BFS of sintered zirconia printed at 0º (1040.33 ± 236.70 MPa) was also significantly higher (p < 0.05) than at 90º (685.91 ± 139.10 MPa). Sintered specimens printed at 0º exhibited an average grain size of 440 nm and a tetragonal phase. After artificial aging, the DLP-printed group exhibited superior resistance to LTD, with a lower monoclinic phase content (40.78 %) compared to the commercial zirconia group (72.51 %). DLP-printed zirconia exhibited lower transparency than commercial zirconia at both 0.5 mm (23.22 ± 1.55 % vs. 35.67 ± 0.14 %) and 1.0 mm (12.04 ± 1.45 % vs. 28.06 ± 0.25 %) thicknesses. Although the commercial zirconia group showed higher average SBS (10.77 ± 5.10 MPa), the difference was not statistically significant compared to the DLP-printed group (10.26 ± 5.91 MPa). Adhesive failure was the predominant failure mode in both groups. CTE of DLP-printed zirconia (10.56 ×10-6/ºC) was comparable to conventional zirconia (10.50 ×10-6/ºC). The τb of DLP-printed zirconia (26.37 ± 2.37 MPa) was significantly lower (p < 0.05) than that of the conventional zirconia (33.47 ± 3.37 MPa), but both exceeded the ISO 9693:2019 minimal requirement of 20 MPa. Ultra-thin (0.1-0.7 mm) dental veneers were successfully fabricated using the DLP technique. CONCLUSIONS:The DLP technique enables successful fabrication of ultra-thin (0.1-0.7 mm) zirconia dental veneers, with printing orientation significantly influencing the strength of both green and sintered specimens.

Osteochondral defects involve concurrent damage to cartilage and the subchondral bone. Here, a cell-free scaffold is presented, consisting of a 3D-printed bioceramic base combined with a Gelatin methacryloyl (GelMA)-Kartogenin (KGN) hydrogel. This dual induction scaffold is engineered to promote osteogenesis while simultaneously providing localized chondrogenic stimulation. The rabbit bone marrow-derived mesenchymal stromal cells are added as a positive control, while the blank osteochondral defects without scaffold implantation are set as a negative control. It is hypothesized that effective regeneration of subchondral bone is a prerequisite for functional cartilage repair, with effective recruitment of endogenous skeletal stem cells (SSCs). In rabbit osteochondral defects, chondrogenic scaffolds alone regenerated cartilage but caused severe subchondral bone collapse and joint surface deformation persisting through 24 weeks. In contrast, combining osteogenic scaffolds with chondrogenic constructs preserved joint morphology by promoting Gli-1⁺ and Sca-1⁺ skeletal stem cell recruitment and proliferation. Interestingly, adding exogenous mesenchymal stromal cells offered no further benefit. Together, a scaffold capable of recruiting endogenous skeletal stem cells to regenerate subchondral bone is essential for effective osteochondral repair and demonstrates comparable efficacy to stem cell transplantation, demonstrating the viability of a scaffold-only strategy for articular cartilage and subchondral bone tissue regeneration.

Achieving the synergy of low viscosity, high printing precision and enhanced curing ability for lead zirconate titanate (PZT) components is a critical issue in the field of digital light processing (DLP). Herein, the effect of calcination temperature on the morphology and grain size of PSNZT[(Pb0.92Sr0.08)(Zr0.533Ti0.443Nb0.024)O3] ceramic powder has been investigated, and a lowest viscosity, higher printing precision and enhanced curing ability of PSNZT ceramic slurry has been achieved, resulting in a high piezoelectric constant (d33 = 379pC/N) and a high dielectric constant (epsilon r = 1308@100 KHz) via DLP process combined with following sintering densification (1220 degrees C/3 h).

Silicon carbide ceramics, featuring high-temperature resistance, are important in aerospace and renewable energy fields. With the increasing demand for complex ceramic structures, traditional manufacturing methods are becoming inadequate. Additive manufacturing technology based on vat photopolymerization holds great promise. However, during the additive manufacturing process of silicon carbide ceramics, issues such as light absorption and limited curing depth are faced. These problems impede the effective development of high solid loading silicon carbide ceramic slurries. This study systematically probes into the impacts of powder modification, dispersant concentration, and solid loading on the properties of silicon carbide ceramic slurries. Additionally, the oxidation degree of the powder was regulated. A slurry with a 50 vol.% solid loading suitable for vat photopolymerization has been developed, and complex silicon carbide structures have been fabricated. After sintering, the samples exhibit a flexural strength of 235.62 MPa and a density of 2.79 g/cm3, thus enhancing the potential for manufacturing complex ceramic components.

Powder bed fusion (PBF) technology has gained widespread attention for its high fabrication freedom and diverse material options. Among these, multi jet fusion (MJF) has emerged as a high-value polymer-based additive manufacturing method due to its high production efficiency and excellent mechanical properties. However, the understanding of polypropylene (PP) printed using MJF technology remains limited. This study provides a comprehensive evaluation of the properties of MJF-printed PP, focusing on powder morphology, thermal characteristics, crystal phase structure, porosity, mechanical properties, and thermo-mechanical properties, and compares them with those of injection molding (IM) samples. The results indicate that the PP powder, a copolymer with an optimal particle size distribution and broad sintering window, exhibits excellent processability in MJF. The MJF process, characterized by elevated powder bed temperatures and slow cooling rates, promotes higher crystallinity and the formation of the gamma-phase, leading to enhanced tensile and storage modulus compared to IM samples. However, porosity in MJF samples compromises their tensile and impact strength, resulting in lower values than IM counterparts. Innovatively, this study demonstrates that the fusing agent in MJF significantly promotes crystal nucleation and accelerates crystallization during slow cooling, as revealed by isothermal crystallization kinetics analysis.

Multi-material 3D printing holds transformative potential for fabricating complex functional components, yet current vat photopolymerization (VPP) techniques remain limited in material compatibility. Resin tank switching-based VPP methods are restricted to low-viscosity resins, while hybrid strategies integrating Direct Ink Writing with VPP enable the printing of high-viscosity pastes. Nevertheless, these strategies remain insufficient to accommodate the broad spectrum of material viscosities required for diverse multi-material printing applications. Here, we introduce a novel top-down multi-material VPP technique based on the liquid surface supported printing (LSSP) method, which exhibits broad slurry compatibility. The LSSP system accommodates a wide range of materials, including low-viscosity hydrogels, high-viscosity resins, and ceramic slurries. Moreover, it enables continuous gradient material printing—a capability unattainable with conventional VPP. By overcoming limitations in material adaptability and gradient structure fabrication, the LSSP system opens new avenues for manufacturing high-performance, multi-material, and functionally gradient structures.

The ongoing advancement of high-capacity zinc-ion batteries (ZIBs) has intensified the demand for high-massloading electrode materials and innovative electrode architectures. However, challenges such as insufficient infiltration of active materials, sluggish ion transport, and rapid capacity degradation in conventional thick cathodes continue to impede their practical application. In this study, we propose a strategy for fabricating threedimensional (3D) porous cathodes with high mass loading via a multi-step coating process on pre-fabricated conductive frameworks. The multi-channel graphene-based frameworks are initially fabricated through highprecision digital light processing (DLP) of photosensitive graphene oxide (GO) slurry, followed by hightemperature treatment to form reduced graphene oxide (rGO) structures. Utilizing the resulting 3D-printed reduced graphene oxide gyroid (3DP-rGOG) framework, polyaniline-intercalated vanadium oxide (PVO) is uniformly coated onto the expanded surface area via a facile multiple dip-coating method. The hierarchical electrode achieves an ultrahigh mass loading of 20.31 mg cm- 2 and delivers a remarkable discharge capacity of 348 mAh g- 1, benefiting from the enhanced ion transport pathways provided by the 3D architecture. Moreover, aqueous ZIBs assembled with the 3DP-rGOG@PVO electrode exhibit an impressive discharge capacity of 224.9 mAh g-1 at a current density of 2 A g- 1 with a high mass loading of 10.73 mg cm- 2, outperforming most previously reported ZIB cathodes. Collectively, this work presents a straightforward yet effective approach for the construction of high-mass-loading electrodes, enabling efficient ion transport and significantly enhancing the performance of ZIBs.

The stability of particle assemblies is strongly affected by particle shape, yet definitive laws describing key properties, such as the mean contact number and apparent friction coefficient, remain elusive. Using X-ray computed tomography and discrete element simulations, we study 70 assemblies of 3D frictional particles. Once properly rescaled, our data collapse onto master curves, revealing linear relationships linking particle shape to these properties for short-axis particles below certain crossover points. These data suggest that the scaling behavior for the mean contact number can be maintained at lower sphericity than the apparent friction coefficient, indicating different sensitivity of the system's structural versus mechanical properties to particle shape. Through analyzing elongated particles beyond the crossover points, we find that while particle elongation increases the contact number, it has limited effects on improving mechanical stability. This insight, along with the law, paves the route towards optimizing granular packing via manipulating particle shape.