With the growing demand for high-performance thermal management devices, achieving efficient and reliable joining between 3D-printed SiC-reinforced Ti6Al4V composite (3DP-SiC/TC4) and SiC ceramic presents a critical challenge. To enhance the interfacial thermal conductivity, femtosecond laser treatment (FLT) was applied to the SiC ceramic, aiming to construct a uniform striated microstructure. AgCuTi braze was employed to join 3DP-SiC/TC4 with femtosecond laser-treated SiC ceramic (FLT-SiC). The interfacial reaction mechanisms, microstructural evolution, and thermomechanical property optimization were systematically investigated. Based on a series-parallel thermal resistance model, it was revealed that the FLT significantly reduce interfacial thermal resistance by increasing the effective contact area and promoting metallurgical joining. The FLT influences the synergistic effect between geometric morphology and chemical joining. At 0.63 W, a positive synergy between geometric (gain factor ξgeo = 1.083) and interfacial chemical (κchem = 1.087) contributions was achieved. The brazing temperature regulated the extent of interfacial reactions, with 850 ℃ yielding a dense microstructure and optimal properties. The optimal parameters were identified as a laser fluence of 0.63 J/cm2 and a brazing condition of 850 ℃ for 10 min. Under these conditions, the joint exhibited a shear strength of 46.5 ± 2.4 MPa and a thermal conductivity of 24.6 W·m-1·K-1 at 600 ℃. This study provides a novel approach for joining dissimilar materials in thermal management applications, leading to a significant enhancement in the thermal and mechanical performance of the joint.

The reliable joining of graphite and Cu holds significant promise for applications in electronic heat dissipation and sliding electrical contacts. However, the substantial differences in their physicochemical properties, poor wettability, and mismatch in coefficients of thermal expansion often result in low joint strength. In this study, a two-step joining strategy combines surface modification with low-temperature sintering, and this is proposed for fabrication of Cu/graphite joints. First, the graphite surface is modified using an AgCuTi active filler alloy under vacuum conditions. Ti preferentially segregates at and reacts with the graphite interface, leading to the formation of an Ag-Cu eutectic modified layer on the graphite surface. Subsequently, low-temperature joining of the modified graphite to a Cu substrate is achieved via a hot-pressing sintering process using a Ag paste. In the sintered joint, the Ag sintered layer forms sound metallurgical bonds with both the Cu substrate and the graphite-modified layer. When the sintering temperature is 250 °C, the joint exhibits a shear strength of 30 MPa, which is significantly higher than that of a directly brazed joint. This strategy effectively reduces thermal residual stress in the joint during cooling and shifts the failure location from the brittle graphite substrate to the ductile Ag sintered layer, thereby substantially enhancing the mechanical performance.

With the decreasing operating temperatures of solid oxide fuel cells (SOFCs), metallic components, such as interconnects and supports, have become critical to their structural integrity. Chromium-containing alloys are particularly promising for these applications due to their low cost, excellent electrical conductivity, and manufacturability. However, Cr evaporation and subsequent deposition onto the cathode—commonly referred to as Cr-poisoning—compromises cathode performance and reduces SOFC lifespan. To mitigate this issue, protective coatings, primarily transition metal oxides with perovskite or spinel structures, are applied to Cr-containing alloys. Among these, Mn-Co and Mn-Cu spinels stand out for their ability to suppress Cr diffusion, maintain low area-specific resistance (ASR), and achieve coefficients of thermal expansion (CTE) compatible with other SOFC components. This review examines the influence of doping elements, specifically transition metals and rare earth elements, on the performance of Mn-Co spinel coatings. Key aspects analyzed include improvements in ASR, CTE, and the coatings’ capacity to inhibit Cr diffusion, which collectively enhance the durability and reliability of SOFCs. Additionally, the mechanisms underlying these improvements are analyzed, alongside discussions on current challenges and future research directions for optimizing SOFC protective coatings.

Joining aluminum alloy to graphite addresses the urgent need for efficient heat dissipation in electronic devices. This study systematically investigates the process of metallizing graphite surfaces using the AgCuTi filler, and analyzes the influence of temperature on the interface and surface characteristics. The study reveals that needlelike TiC phases are formed on the as-metallized layer surface at 900 degrees C to 950 degrees C. Subsequently, the as-metallized graphite is brazed to 3D printed 6061 aluminum alloy using the Al-Si-Mg filler, and the microstructure and properties of the joint are analyzed. Results indicate that the joint region mainly contains Al(s,s), zeta-Ag2Al, theta-Al2Cu, TiC, Al(s,s) + zeta, and (Al,Si)(3)Ti. The shear strength of the 3D printed 6061 aluminum alloy/graphite joints brazed from 560 degrees C to 590 degrees C remains relatively stable at about 40 MPa. The thermal conductivity of the as-brazed joints is significantly higher than that of the unbrazed joints. The brazing seam establishes efficient heat transfer pathways from the aluminum alloy to the graphite, improving the thermal conductivity of the joint. The joint brazed at 590 degrees C for 10 min achieves the highest thermal conductivity of 151.5 W.m(-1).K-1 at room temperature and 120.4 W.m(-1).K-1 at 500 degrees C. This study provides an important reference for the application of brazing technology for 3D printed alloy and carbon materials in advanced thermal management systems.

Ceramic-reinforced aluminum matrix composites possess exceptional properties, which makes them promising candidates for a wide range of applications. However, the brittle Al4C3 phases, which can severely deteriorate the properties of the joint, are often formed in the joint obtained using conventional fusion welding techniques. In this study, an ultrafast laser welding approach is adopted for the first time to join aluminum matrix composites reinforced with 45 vol.% SiC particles. The achieved joints appear to be sound, free from macroscopic defects, and the four-point bending strength of the joint can reach 321 MPa. The effects of laser power and welding speed on the microstructure and mechanical properties are systematically examined. Comprehensive characterization reveals that, unlike conventional laser welding, no brittle and hydrolyzable Al4C3 phase is detected in the welding seam. Instead, the ultrafast laser irradiation promotes the decomposition of SiC particles, which subsequently react with molten aluminum to form nanoscale Al4SiC4 phases. These precipitates are uniformly dispersed throughout the matrix, thus enhancing the joint performance.

The rising demand for high-end equipment manufacturing across the energy, electronics, and aerospace industries has necessitated the development of effective methods for joining dissimilar materials, particularly metals. Dissimilar metal brazing is a notable joining technique owing to its advantages such as low joining temperatures, efficient sealing capability, and applicability to complex structures; it is therefore a central topic in materials processing research. However, dissimilar metal brazing faces significant technical challenges that impede its broader industrial use. Differences in the physical and chemical properties of the base materials, such as melting points, thermal expansion behaviors, and chemical reactivities, can cause problems such as poor wetting of filler metals, generation of residual stresses (leading to joint cracking), and the formation of brittle intermetallic compounds that degrade mechanical strength. Additionally, base materials with irregular shapes further complicate the brazing process, leading to uneven heat distribution, misalignment, and difficulties in achieving effective filler-metal wetting. In this review, the key challenges and underlying mechanisms in dissimilar metal brazing are examined. Current strategies for improving brazability, including surface modification techniques, innovations in high-performance filler metals, and optimization of process parameters, are also systematically reviewed. This review also addresses issues arising from component shape and size differences and proposes viable solutions. Finally, future directions for dissimilar metal brazing are explored, highlighting the potential of intelligent process control systems and the development of environmentally sustainable brazing materials.

High-entropy alloys (HEAs) offer exceptional properties for advanced applications, yet reliable joining techniques remain challenging. This study investigates the microstructure and mechanical properties of Al0.3CoCrFeNi HEA brazed with a TiZrNiCu filler at 960 degrees C for 10 min. The TiZrNiCu filler, characterized by an amorphous structure with a melting point at similar to 835 degrees C, ensures thermal compatibility with the HEA. The optimal joint exhibits a balanced microstructure comprising Ti-2(Ni, Cu) intermetallic compounds (IMCs), C15 Laves phases, Ti (s, s) solid solution, sigma phases, and body-centered cubic (BCC) solid solution phases. Room-temperature shear strength peaks at similar to 153 MPa under these conditions, demonstrating a tradeoff between strength and ductility. Microstructural evolution reveals Ti/Cu diffusion from the filler, elemental redistribution driven by base-metal/IMC interactions, and the formation of solid solution and IMC phases. Fracture analysis indicates that 10-min brazing minimizes brittle phases while maintaining a balanced microstructure. This work establishes TiZrNiCu as a promising medium-entropy brazing filler for HEAs, balancing process efficiency and joint performance.

Niobium alloy and nickel-based superalloy exhibit high strength and remarkable corrosion resistance, joining them to fabricate composite structures could help to realize their potential. Nevertheless, research attention devoted to the joining of niobium alloy with nickel-based superalloy remains scarce. This study investigates direct diffusion bonding of these two materials. The microstructure of the joint is characterized in detail, with the typical joint microstructure being identified as GH4099 / (Ni, Cr)ss + Ni3Nb + Cr2Nb / Ni3Nb / Ni6Nb7 / Nb alloy. With holding time fixed at 60min and diffusion pressure maintained at 15MPa, the effects of diffusion bonding temperature on the microstructure and mechanical properties of joints are examined within the range of 900-1150 ℃. An increase in bonding temperature results in the formation of different intermetallic compounds within the joint. The primary cause of joint fracture is the presence of Cr2Nb and Ni6Nb7. The tensile strength of the joint initially increases and then decreases with increasing temperature, reaching a maximum value of 204MPa. This work expands the range of methods for joining niobium alloys to nickel-based superalloys, enabling bonding without the introduction of additional elements.

The repair of full-thickness skin defects remains a critical biomedical challenge owing to the high risks of infection, persistent inflammation, and irreversible tissue loss, highlighting the urgent need for bioadhesive materials that integrate strong adhesion, biocompatibility, and antibacterial functionality. In this study, a natural bioadhesive termed Eucommia ulmoides gum natural bioadhesive (EUGNBA) was developed through a thermally induced conformational reorganization of Eucommia ulmoides gum, enabling robust wet-tissue adhesion without chemical crosslinkers. EUGNBA demonstrated outstanding mechanical performance, exceeding porcine fibrin adhesives in shear strength, tensile strength, and interfacial toughness by 2.06-, 2.64-, and 3.49-fold, respectively. Raman mapping and spectroscopic characterization confirmed that these superior adhesive properties originated from its conformational adaptability and multiscale interfacial interactions. Beyond mechanical superiority, EUGNBA displayed broad-spectrum antibacterial efficacy exceeding 99.9% against Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa, along with excellent cytocompatibility, negligible hemolysis, and tunable biodegradability in vivo. In rat wound models, EUGNBA markedly enhanced the healing of incisional and full-thickness wounds by promoting re-epithelialization, collagen maturation, and neovascularization, accompanied by activation and coordination of NF-κB-mediated inflammation resolution, Wnt-driven epithelial regeneration, and tight-junction-associated barrier restoration. Compared with commercial adhesives and sutures, EUGNBA achieved superior tissue integration and facilitated the regeneration of dermal appendages. Collectively, this study establishes a scalable approach for engineering conformationally adaptive natural bioadhesives with integrated antibacterial and regenerative functions, offering a robust and scalable platform toward next-generation wound bioadhesives and clinical translation.

High-density power electronics requires efficient thermal substrates to dissipate heat and extend the lifespan of devices. In this study, a high-thermal-conductivity SiC/graphene heterostructure was successfully fabricated by vacuum brazing using AgCuTi filler. A nanoscale transition layer was formed at the brazed joint, achieving atomic-level bonding with both the substrates. Based on interatomic bonding effects, highly efficient phonon transport channels were formed in the joint region, significantly enhancing the directional heat flow and overall thermal transmission efficiency. The SiC/graphene heterostructure substrate showed high thermal performance with an in-plane thermal conductivity of 201.59 W/(m center dot K), which is 40 % higher than that of unmodified SiC. The peak heating rate of the brazed sample, 1.8 degrees C/s, is nearly 300 % higher than that of unmodified SiC. Thus, surface modification of SiC heat-dissipation substrates with graphene offers a novel approach for developing multifunctional thermal substrates.

The hardness and brittleness of transparent ceramic make it difficult to be prepared in large scale and limit its application. This paper tries to solve this problem from the perspective of realizing its own reliable joining. Without interlayer and preheating, MgAl2O4 transparent ceramics have been directly welding by ultrashort pulse laser for the first time. The typical structure of the joint was systematically characterised, it can be found that at the bonding area, parts of MgAl2O4 crystals were transformed into amorphous. Under the optimal welding parameters (laser power: 550 mW, scanning speed: 0.1 mm/s), the joint achieved a maximum shear strength of approximately 28 MPa. This paper provides a new methodology for MgAl2O4 transparent ceramics joining, owning high efficiency and simplicity, which makes efforts for broadening the application of transparent ceramics.

Polycrystalline cubic boron nitride (PCBN) ceramics have been successfully joined with M42 steel via partial transient liquid phase (PTLP) bonding. To advance joint quality, this study systematically investigates element diffusion behavior and interfacial microstructural evolution of a pre-melted CuNi interlayer during joining. Under optimized parameters (1080 degrees C/30 min/0.1 MPa), a joint with homogeneous microstructure and high shear strength (132 MPa) is achievable. The brazing seam primarily consists of a Cu-based solid solution with minor dispersed CuNi2Ti phases. Analysis of the Cu-Ni-Ti ternary phase diagram reveals that elevating the brazing temperature above 1056 degrees C suppresses brittle Ti-Cu and Ti-Ni intermetallic compound formation. Notably, the relatively low diffusion coefficient (9.2 x 10-14 m2/s) and high activation energy (230 kJ/mol) for Ti diffusion within the CuNi interlayer inhibit excessive Ti penetration into M42 steel and subsequent brittle phase formation, thereby enabling fabrication of high-integrity brazed joints.

Tripterygium glycosides extract (TGE), the primary active component of tripterygium glycosides tablets, is widely used for immune-related disorders but raises significant clinical concerns regarding cholestatic drug-induced liver injury. As conventional models fail to fully recapitulate the complex pathogenesis of traditional Chinese medicine toxicity, this study aimed to elucidate the mechanisms of TGE-induced cholestatic injury using a biomimetic microfluidic liver-on-a-chip platform. The chip integrated rat precision-cut liver slices (PCLSs) and human endothelial cells (EA.hy926) to simulate the hepatic sinusoidal microenvironment. Following TGE exposure (15-135 μg/mL for 12 and 24 h), vascular barrier integrity was maintained, while liver injury markers (ALT, AST, TBA, DBIL) significantly increased in a dose- and time-dependent manner, accompanied by progressive histopathological deterioration in PCLSs. Mechanistically, TGE triggered severe oxidative stress (decreased SOD/GSH/GSH-Px and increased MDA) and upregulated pro-inflammatory cytokines (IL-4 and IL-1β). Consequently, the expression of the bile acid receptor FXR and transporters (BSEP and MRP2) was significantly downregulated. In conclusion, TGE induces cholestatic liver injury via a sequential pathway: oxidative stress initiates an immune-inflammatory response, which subsequently suppresses the FXR/BSEP/MRP2 axis. Future studies should focus on developing fully humanized liver-on-a-chip systems to further validate these mechanisms and improve clinical translational significance.

This study aimed to develop an ultra-performance liquid chromatography(UPLC) method for the quantitative analysis of xanthones and oligosaccharide esters in Polygalae Radix(PR), and to explore a retention-time-ratio-based strategy for inter-column method transfer. Chromatographic separation was performed on a Waters ACQUITY UPLC BEH C_(18) column(2.1 mm×50 mm, 1.7 μm) by gradient elution using 0.1% formic acid in water and acetonitrile with detection at 238 nm. The UPLC fingerprints of 31 batches of PR samples were established, with 21 common peaks marked and identified by UPLC-Q-TOF-MS~E. Through systematic methodological validation, a quantitative method was developed for the simultaneous determination of 7 bioactive components, namely sibiricose A_1, sibiricaxanthone B, polygalaxanthone Ⅷ, polygalaxanthone Ⅺ, polygalaxanthone Ⅲ, 3,6'-disinapoyl sucrose, and tenuifoliside A. A quantitative analysis of multiple components by single marker(QAMS) method was established using polygalaxanthone Ⅲ as the internal reference substance, and its accuracy was compared with that of the external standard method(ESM). The feasibility of method transfer across different columns and instruments was also investigated. All 7 analytes showed good linearity(r>0.999) within their respective concentration ranges with mean recoveries of 94.31%-99.02%(RSD<2.0%, n=6). The relative error(RE) between QAMS and ESM was less than 4.0%, and the paired t-test indicated no significant difference between the two methods. Preliminary studies of method transfer on 9 C_(18) columns from 3 manufacturers on Waters UPLC systems of two models demonstrated that gradient time adjustment based on retention time ratio could maintain the elution behavior and separation characteristics of the target peaks, though the generalizability of this strategy requires further validation. The established UPLC-QAMS method is accurate and reliable for the quality control of PR. The inter-column method transfer strategy provides preliminary reference for the broader application of analytical methods.

Eucommia ulmoides gum (EUG) is a natural trans−1,4-polyisoprene with promising applications in green elastomers and bio-based materials. However, its extraction is limited by strong confinement within a cellulose-hemicellulose-lignin matrix. This study aims to elucidate a hydrogen bond competition mechanism to enable efficient cell wall deconstruction and EUG release. Deep eutectic solvent systems were designed by tuning hydrogen bond donors and acceptors to selectively disrupt polysaccharide hydrogen bonding networks. The results show that hydrogen bond basicity, acidity, and viscosity collectively regulate solvent penetration and competitive interactions, with the choline chloride-lactic acid system providing the optimal balance between deconstruction efficiency and mass transfer. Spectroscopic analyses reveal pronounced weakening and rearrangement of cellulose and hemicellulose hydrogen bonding networks, which correlate with enhanced EUG release, structural loosening, and controlled molecular weight distribution. Coupling this system with petroleum ether extraction and optimizing conditions via response surface methodology achieves an EUG extraction yield of 20.76 ± 0.96%, with an extraction efficiency of 90.10 ± 4.17% and a purity of 98.24 ± 0.93%, while preserving EUG integrity. The extracted EUG retains its characteristic trans-1,4-polyisoprene structure and exhibits favorable thermal and mechanical properties. These findings provide a mechanism-driven basis for scalable and sustainable extraction processes and offer guidance for the rational design of solvent systems in industrial biomass valorization.

Seven undescribed steroidal glycosides (compounds 1-7) and nine known glycosides (compounds 8-16) were isolated from the ethyl acetate fraction of Marsdenia tenacissima, which is frequently utilized as an adjunctive treatment alongside conventional chemotherapy for various solid tumors in clinical practice in China. All of these compounds are naturally occurring polyoxypregnane glycosides, except for compound 5, which possesses a unique aglycone skeleton with a conjugated moiety. The structural elucidation of these compounds was achieved through comprehensive spectroscopic analysis and electronic circular dichroism (ECD) calculations. An integrated strategy combining network pharmacology and molecular docking revealed that cytochrome P450 3A4 (CYP3A4) is closely associated with multidrug resistance. The inhibition activities of cytochrome P450 enzymes were assessed using a cocktail-probe assay, and the inhibition of CYP3A4 was further validated using a single-substrate assay in pooled human liver microsomes. All isolated compounds exhibited statistically significant inhibitory effects on CYP3A4 enzymatic activity. The steroidal glycosides derived from M. tenacissima are expected to serve as novel inhibitors of CYP3A4, thereby enhancing the therapeutic efficacy of chemotherapeutic agents that are substrates of this enzyme.

Reliable Cu–Cu bonding at low temperatures is widely regarded as a promising approach for electronic packaging. This study proposes the in-situ growth of Cu nanoparticles (NPs) for direct low-temperature Cu–Cu bonding via oxidizing the Cu surface and then reducing, without introducing additional Cu NPs or Cu-containing reagent. A high shear strength of 67.2 MPa is obtained at 150 °C/5 min/20 MPa in air, and the strength further increases to 98.4 MPa when the bonding temperature is raised to 225 °C. In addition, after aging in air at 250 °C for 500 h, the joint prepared at 150 °C/5 min/20 MPa retains a shear strength of 51.8 MPa, indicating excellent high-temperature reliability. The in-situ synthesized Cu NPs by oxidation and reduction show a well-bonded interface with the substrate, improving the driving force for the subsequent sintering. The grain orientation, dislocations and stacking faults within the synthesized Cu NPs are also beneficial to the sintering, thereby promoting rapid densification and enabling high-strength Cu–Cu bonding under low-temperature conditions.

Low-temperature Cu sintering is used as a die-bonding strategy for the third-generation power device, and the Cu-sintered joints require long-term stability at elevated temperature. In this work, we investigate the thermal stability and microstructural evolution of the Cu interconnect joints with an ultra-thin sintered layer at the temperature of 250 °C in air. The as-prepared joint shows a dense well-bonded interface with low porosity before the thermal aging test. The average shear strength of the joints increases from 85.5 MPa to 91.3 MPa after aging up to 300 h. With further increase in aging time, the shear strength begins to decrease. However, the strength remains at a high level of 69.8 MPa even after 500 h of aging, satisfying the requirements for high-temperature stability. At short aging times, the porosity within the interface reduces slightly, and the fracture exhibits distinct ductile characteristics. When the aging time exceeds 300 h, the oxide content at the interface increases from the outer region toward the inner part, and aging cracks eventually appear at the edge of the sintered layer. Therefore, it is demonstrated that the dense and thin sintered layer limits oxygen diffusion, guaranteeing the high-temperature stability of the sintered joint.

The reaction between SiC and Ni-based filler metals produces brittle Ni-Si compounds, severely degrading joint mechanical performance. This study proposes an ultra-fast Joule heating strategy for joining SiCf/SiC composites using TiNiNb filler metals, where a 3D carbon fiber network serves as both an integrated heating source and reinforcing phase, completing the entire process within 50 s with a heating rate of 700 degrees C/s. DFT calculations and experimental analyses reveal that electron transfer from Ti atoms to carbon enables rapid TiC nucleation at the interface, kinetically suppressing Ni diffusion and subsequent brittle Ni-Si formation. Molecular dynamics (MD) simulations further reveal that the Ti-C-mediated interface significantly augments the intrinsic bonding energy and promotes a more uniform dislocation distribution. The 3D carbon fiber network serves as a stress-buffering layer, redistributing interfacial stress to alleviate thermal expansion mismatch between SiCf/SiC and the filler metal. This approach yields joints with a shear strength of 39.05 MPa, representing a 121.7% enhancement compared to conventional furnace brazing, offering a promising pathway for the reliable joining of aerospace hot-end components under extreme conditions.