Magnesium alloys have gained extensive applications across various industries,including aerospace,transportation,and civil construction,owing to their excellent combinations of high specific strength and stiffness[1]....Magnesium alloys have gained extensive applications across various industries,including aerospace,transportation,and civil construction,owing to their excellent combinations of high specific strength and stiffness[1].However,their lim-ited strength due to the lack of effective strengthening phases has hindered their broader industrial applications[2].Never-theless,it has been challenging to achieve significant strength-ening due to the restricted solubility of alloying elements in magnesium[3].Thus,more and more efforts have been made to explore the concept of secondary phase-reinforced magne-sium alloys[2,4,5],where the secondary phase acts as re-inforcing agents within the magnesium matrix,resembling a composite material.展开更多
In this study,a new linear friction welding(LFW)process,embedded LFW process,was put forward,which was mainly applied to combination manufacturing of long or overlong loadcarrying titanium alloy structural components ...In this study,a new linear friction welding(LFW)process,embedded LFW process,was put forward,which was mainly applied to combination manufacturing of long or overlong loadcarrying titanium alloy structural components in aircraft.The interfacial plastic flow behavior and bonding mechanism of this process were investigated by a developed coupling EulerianLagrangian numerical model using software ABAQUS and a novel thermo-physical simulation method with designed embedded hot compression specimen.In addition,the formation mechanism and control method of welding defects caused by uneven plastic flow were discussed.The results reveal that the plastic flow along oscillating direction of this process is even and sufficient.In the direction perpendicular to oscillation,thermo-plastic metals mainly flow downward along welding interface under coupling of shear stress and interfacial pressure,resulting in the interfacial plastic zone shown as an inverted“V”shape.The upward plastic flow in this direction is relatively weak,and only a small amount of flash is extruded from top of joint.Moreover,the wedge block and welding components at top of joint are always in un-steady friction stage,leading to nonuniform temperature field distribution and un-welded defects.According to the results of numerical simulation,high oscillating frequency combined with low pressure and small amplitude is considered as appropriate parameter selection scheme to improve the upward interfacial plastic flow at top of joint and suppress the un-welded defects.The results of thermo-physical simulation illustrate that continuous dynamic recrystallization(CDRX)induces the bonding of interface,accompanying by intense dislocation movement and creation of many low-angle grain boundaries.In the interfacial bonding area,grain orientation is random with relatively low texture density(5.0 mud)owing to CDRX.展开更多
The growth of intermetallic compounds at the interface between solid Al and Fe and the effects of intermetallic compound layers on the interfacial bonding of clad materials were investigated. The results showed that t...The growth of intermetallic compounds at the interface between solid Al and Fe and the effects of intermetallic compound layers on the interfacial bonding of clad materials were investigated. The results showed that the interface between the solid Fe and Al formed by heat-treatment consisted of Fe2Al5 and FeAl3 intermetallic compound layers, which deteriorated the interfacial bonding strength. Fractures occurred in the intermetallic compound layer during the shear testing. The location of the fracture depended on the defects of microcracks or voids in the intermetallic compound layers. The microcracks in the intermetallic compound layer were caused by the mismatch of thermal expansion coefficients of materials during cooling, and the voids were consistent with the Kirkendall effect. The work will lay an important foundation for welding and joining of aluminum and steel, especially for fabrication of Al-Fe clad materials.展开更多
Interfacial bonding in as deposited and annealed Co/C soft X ray multilayer structures is investigated by X ray photo electron spectroscopy (XPS).It is found that there is interdiffusion between cobalt and carbon ...Interfacial bonding in as deposited and annealed Co/C soft X ray multilayer structures is investigated by X ray photo electron spectroscopy (XPS).It is found that there is interdiffusion between cobalt and carbon in the as deposited Co/C multilayers,and this is confirmed by structure characterization using low angle X ray diffraction (LAXD).The calculation of the chemical shifts in Co C system based on Miedemas macroscopic atom model suggests that it is impossible to detect the chemical shift experimentally in the Co C compound,which is consistent with the XPS results.The presence of metallic carbide bonding is evidenced through the nature of the carbon bonding in survey taken at Co C and C Co interfaces of annealed samples.Our results also indicate that XPS is a direct method to probe the chemical bonding at the interfaces.展开更多
Cu-based and Cu-alloy-based diamond composites were made by high-pressure-high-temperature （HPHT） sintering with the aim of maximizing the thermal conductivity of the composites. Improvements in interfacial bonding ...Cu-based and Cu-alloy-based diamond composites were made by high-pressure-high-temperature （HPHT） sintering with the aim of maximizing the thermal conductivity of the composites. Improvements in interfacial bonding strength and thermo-physical properties of the composites were achieved using an atomized copper alloy with minor additions of Co, Cr, 13, and Ti. The thermal conductivity （TC） oh- mined exhibited as high as 688 W.m-1.K-1, but also as low as 325 W.m-1.K-l. A large variation in TC can be rationalized by the discrepancy of diamond-matrix interfacial bonding. It was found from fractography that preferential bonding between diamond and the Cu-alloy matrix occurred only on the diamond {100} faces. EDS analysis and Raman spectra suggested that selective interfacial bonding may be attributed to amorphous carbon increasing the wettability between diamond and the Cu-alloy matrix. Amorphous carbon was found to significantly affect the TC of the composite by interface modification.展开更多
7075 aluminum billets were fabricated by micro droplet deposition manufacturing technique, and the influence of interracial bonding between metal droplets on the tensile properties was studied. Three sets of samples w...7075 aluminum billets were fabricated by micro droplet deposition manufacturing technique, and the influence of interracial bonding between metal droplets on the tensile properties was studied. Three sets of samples were manufactured under different temperature conditions, and their mechanical properties were compared. The results show that the temperature of the metal droplets and substrate significantly affect the tensile strength of the sample. Moreover, with proper temperature setting, the 7075 aluminum billets manufactured by micro metal droplet deposition could achieve very good mechanical properties with a tensile strength of 373 MPa and an elongation of 9.95%, which are very similar to those of an ex truded sample. Moreover, a metallurgical bonding diagram based on numerical calculations of interfacial temperature was established to predict the interfacial bonding state. In addition, the fracture morphologies of these specimens were observed. It is indicated that there was a significant transformation of failure mechanism with the improvement of metallurgical bonding, which agreed well with the numerical results.展开更多
In this study,an overcasting process followed by a low-temperature(200°C)annealing schedule has been developed to bond magnesium to aluminum alloys.ProCAST software was used to optimize the process parameters dur...In this study,an overcasting process followed by a low-temperature(200°C)annealing schedule has been developed to bond magnesium to aluminum alloys.ProCAST software was used to optimize the process parameters during the overcasting process which lead to Mg/Al bimetallic structures to be successfully produced without formation of Mg-Al intermetallic phases.Detailed microstructure evolution during annealing,including the formation and growth of Al-Mg interdiffusion layer and intermetallic phases(Al12Mg17 and Al3Mg2),was experimentally observed for the first time with direct evidence,and predicted using Calculation of Phase Diagrams(CALPHAD)modeling.Maximum interfacial strength was achieved when the interdiffusion layer formed at the Mg/Al interface reached a maximum thickness the without formation of brittle intermetallic compounds.The precise diffusion modeling of the Mg/Al interface provides an efficient way to optimize and control the interfacial microstructure of Mg/Al bimetallic structures for improved interfacial bonding.展开更多
A facile and innovative method to improve bonding between the two parts of compound squeeze cast Al/Al-4.5 wt.%Cu macrocomposite bimetals was developed and its effects on microstructure and mechanical properties of th...A facile and innovative method to improve bonding between the two parts of compound squeeze cast Al/Al-4.5 wt.%Cu macrocomposite bimetals was developed and its effects on microstructure and mechanical properties of the bimetal were investigated.A special concentric groove pattern was machined on the top surface of the insert(squeeze cast Al-4.5 wt.%Cu) and its effects on heat transfer,solidification and distribution of generated stresses along the interface region of the bimetal components were simulated using ProCAST and ANSYS softwares and experimentally verified. Simulation results indicated complete melting of the tips of the surface grooves and local generation of large stress gradient fields along the interface. These are believed to result in rupture of the insert interfacial aluminum oxide layer facilitating diffusion bonding of the bimetal components. Microstructural evaluations confirmed formation of an evident transition zone along the interface region of the bimetal. Average thickness of the transition zone and tensile strength of the bimetal were significantly increased to about 375 μm and 54 MPa, respectively, by applying the surface pattern.The proposed method is an affordable and promising approach for compound squeeze casting of Al-Al macrocomposite bimetals without resort to any prior cost and time intensive chemical or coating treatments of the solid insert.展开更多
Tungsten(W)and stainless steel(SS)are well known for the high melting point and good corrosion resistance respectively.Bimetallic W-SS structures would offer potential applications in extreme environments.In this stud...Tungsten(W)and stainless steel(SS)are well known for the high melting point and good corrosion resistance respectively.Bimetallic W-SS structures would offer potential applications in extreme environments.In this study,a SS→W→SS sandwich structure is fabricated via a special laser powder bed fusion(LPBF)method based on an ultrasonic-assisted powder deposition mechanism.Material characterization of the SS→W interface and W→SS interface was conducted,including microstructure,element distribution,phase distribution,and nano-hardness.A coupled modelling method,combining computational fluid dynamics modelling with discrete element method,simulated the melt pool dynamics and solidification at the material interfaces.The study shows that the interface bonding of SS→W(SS printed on W)is the combined effect of solid-state diffusion with different elemental diffusion rates and grain boundary diffusion.The keyhole mode of the melt pool at the W→SS(W printed on SS)interface makes the pre-printed SS layers repeatedly remelted,causing the liquid W to flow into the sub-surface of the pre-printed SS through the keyhole cavities realizing the bonding of the W→SS interface.The above interfacial bonding behaviours are significantly different from the previously reported bonding mechanism based on the melt pool convection during multiple material LPBF.The abnormal material interfacial bonding behaviours are reported for the first time.展开更多
Interfacial bonding,microstructures,and mechanical properties of an explosively-welded H68/AZ31B clad plate were systematically studied.According to the results,the bonding interface demonstrated a“wavy-like”structu...Interfacial bonding,microstructures,and mechanical properties of an explosively-welded H68/AZ31B clad plate were systematically studied.According to the results,the bonding interface demonstrated a“wavy-like”structure containing three typical zones/layers:(1)diffusion layer adjacent to the H68 brass plate;(2)solidification layer of melted metals at the interface;(3)a layer at the side of AZ31B alloy that experienced severe deformation.Mixed copper,CuZn_(2),andα-Mg phases were observed in the melted-solidification layer.Regular polygonal grains with twins were found at the H68 alloy side,while fine equiaxed grains were found at the AZ31B alloy side near the interface due to recrystallization.Nanoindentation results revealed the formation of brittle intermetallic CuZn_(2) phases at the bonding interface.The interface was bonded well through metallurgical reactions due to diffusion of Cu,Zn,and Mg atoms across the interface and metallurgic reaction of partially melted H68 and AZ31B alloys.展开更多
The main Iimitation to the toughening of the α-Al2O3/Ni composite is the poor bonding atthe interface. which causes the nickel particles to be pulled-out during crack propagation with-out obvious plastic deformation....The main Iimitation to the toughening of the α-Al2O3/Ni composite is the poor bonding atthe interface. which causes the nickel particles to be pulled-out during crack propagation with-out obvious plastic deformation. A proper control of oxygen content at the Al2O3-Ni interfacecan promote wetting at the intedece, and produce a mechanically interlocked and chemically strengthened intedece, causing most of the nickel particles to be stretched to failure and to expe-rience severe plastic deformation during crack propagation in the composite. Fracture toughnesstesting using a modified double cantilever beam method with in situ observation of crack prop-agation in a scanning electron microscope shows that the composite with the strengthenedinterface has a more desirable R-curve behaviour and a higher fracture toughness value than thenormal composite.展开更多
Photocatalytic overall pure water splitting is a promising method for generating green hydrogen energy under mild conditions.However,this process is often hindered by sluggish electron-hole separation and transport.To...Photocatalytic overall pure water splitting is a promising method for generating green hydrogen energy under mild conditions.However,this process is often hindered by sluggish electron-hole separation and transport.To address this,a step-scheme(S-scheme)B-doped N-deficient C_(3)N_(4)/O-doped C_(3)N_(5)(BN-C_(3)N_(4)/O-C_(3)N_(5))heterojunction with interfacial B-O bonds has been constructed.Utilizing Pt and Co(OH)_(2) as co-catalysts,BN-C_(3)N_(4)/O-C_(3)N_(5) S-scheme heterojunction demonstrates significantly enhanced photocatalytic activity for overall pure water splitting under visible light,achieving H_(2) and O_(2) evolution rates of 40.12 and 19.62μmol/h,respectively.Systematic characterizations and experiments revealed the performance-enhancing effects of the enhanced built-in electric field and the interfacial B-O bonding.Firstly,the strengthened built-in electric field provides sufficient force for rapid interfacial electron transport.Secondly,by reducing the transport energy barrier and transfer distance,the interfacial B-O bonds facilitate rapid recombination of electrons and holes with relatively low redox potential via the S-scheme charge-transfer route,leaving the high-potential electrons and holes available for H^(+)reduction and OH^(-)oxidation reactions.Overall,the photocatalytic efficiency of BN-C_(3)N_(4)/O-C_(3)N_(5) S-scheme heterojunction was significantly improved,making it a promising approach for green hydrogen production through overall pure water splitting.展开更多
Multi-material additive manufacturing(MMAM)takes full advantage of the ability to arbitrarily place materials of addi-tive manufacturing technology,enabling immense design free-dom and functional print capabilities.Am...Multi-material additive manufacturing(MMAM)takes full advantage of the ability to arbitrarily place materials of addi-tive manufacturing technology,enabling immense design free-dom and functional print capabilities.Among MMAM technologies,projection stereolithography(PSL)exhibits a great balance of high resolution and fast printing speed.However,fabrication accuracy of multi-material PSL is hin-dered by large overcure used to strengthen interfacial bond-ing weakened by chemical affinity and material-exchange process.We present a novel multi-step exposure method for multi-material PSL process to overcome this shortcoming.Firstly,the whole layer is moderately exposed producing over-cure of single-material PSL level to generate geometries.Then weakened interfaces are strengthened individually with addi-tional steps of exposure.The multi-step exposure is integrated into the already efficient materials printing order of multi-material PSL process.Curing depth and overcure of photocur-able resins are modeled and characterized.Exposure required to achieve sufficient interfacial bonding of single-material interfaces built through material-exchange process and multi-material interfaces with altering materials printing order is determined with tensile tests.Microfluidic channels are used to compare fabrication accuracy of traditional single-step exposure and our multi-step exposure method.This method can be widely applied in multi-material PSL to improve fabri-cation accuracy in a variety of applications including micro-fluidic devices.展开更多
Devising robust S-scheme photocatalysts is of central importance for achieving high-efficient micropollu-tant decontamination.However,the conscious optimization of S-scheme system with high performance remains a prime...Devising robust S-scheme photocatalysts is of central importance for achieving high-efficient micropollu-tant decontamination.However,the conscious optimization of S-scheme system with high performance remains a prime challenge.Herein,carbon quantum dots(CDs)and Mn_(0.5)Cd_(0.5)S(MCS)are mounted on BiOBr(BOB)microspheres,establishing an advanced S-scheme heterojunction with interfacial Bi-S bond.The interfacial Bi-S bonds function as superb channels at atomic-scale to abate the energy barrier for S-scheme charge transportation.Meanwhile,CDs serve as electron collectors to preserve highly reductive electrons from MCS,further augmenting the spatial separation of photo-carriers.Therefore,the optimized CDs/MCS/BOB(MBC)heterojunction manifests significantly strengthened tetracycline hydrochloride(TC)destruction activity and its reaction rate constant is approximately 3.1,2.2,2.1,and 1.5 folds that than that of MCS,BOB,BOB/CDs and MCS/BOB.In addition,MBC exhibits high stability and significant resistance to environmental interferences.The toxicology evaluation confirms the effective abatement of toxicity of TC after treatment.This achievement demonstrates the benefits of CDs-optimized S-scheme photosystems with chemical bonds for photocatalytic water decontamination.展开更多
A novel photocatalytic cocatalyst, MoC quantum dots integrated into N-doped carbon microflowers (MoC–NC), was synthesized, establishing a key Mo–N interfacial bond. The Mo–N bond's regulation was achieved by ad...A novel photocatalytic cocatalyst, MoC quantum dots integrated into N-doped carbon microflowers (MoC–NC), was synthesized, establishing a key Mo–N interfacial bond. The Mo–N bond's regulation was achieved by adjusting the pH of Mo-polydopamine precursor solutions. A composite photocatalyst, MoC–NC/CdS (MNS), was formed by in situ growth of nano-CdS on MoC–NC. The pH during synthesis, crucial for Mo–N bond formation, significantly influenced Cr(Ⅵ) reduction and H_(2) evolution performance. The optimal MNS, created at pH 9.0, demonstrated 99.2% reduction efficiency for Cr(Ⅵ) in 20 min and H_(2) evolution rate of 11.4 mmol g^(-1) h^(-1) over 3 h, outperforming Pt/CdS. Mechanistic studies and density functional theory revealed MoC–NC's role in enhancing light absorption, reaction kinetics, and electron transport, attributing to its ultra-small quantum dots and abundant Mo–N bonds.展开更多
The use of lithium-sulfur batteries under high sulfur loading and low electrolyte concentrations is severely restricted by the detrimental shuttling behavior of polysulfides and the sluggish kinetics in redox processe...The use of lithium-sulfur batteries under high sulfur loading and low electrolyte concentrations is severely restricted by the detrimental shuttling behavior of polysulfides and the sluggish kinetics in redox processes.Two-dimensional(2D)few layered black phosphorus with fully exposed atoms and high sulfur affinity can be potential lithium-sulfur battery electrocatalysts,which,however,have limitations of restricted catalytic activity and poor electrochemical/chemical stability.To resolve these issues,we developed a multifunctional metal-free catalyst by covalently bonding few layered black phosphorus nanosheets with nitrogen-doped carbon-coated multiwalled carbon nanotubes(denoted c-FBP-NC).The experimental characterizations and theoretical calculations show that the formed polarized P-N covalent bonds in c-FBP-NC can efficiently regulate electron transfer from NC to FBP and significantly promote the capture and catalysis of lithium polysulfides,thus alleviating the shuttle effect.Meanwhile,the robust 1D-2D interwoven structure with large surface area and high porosity allows strong physical confinement and fast mass transfer.Impressively,with c-FBP-NC as the sulfur host,the battery shows a high areal capacity of 7.69 mAh cm^(−2) under high sulfur loading of 8.74 mg cm^(−2) and a low electrolyte/sulfur ratio of 5.7μL mg^(−1).Moreover,the assembled pouch cell with sulfur loading of 4 mg cm^(−2) and an electrolyte/sulfur ratio of 3.5μL mg^(−1) shows good rate capability and outstanding cyclability.This work proposes an interfacial and electronic structure engineering strategy for fast and durable sulfur electrochemistry,demonstrating great potential in lithium-sulfur batteries.展开更多
Inspired by natural photosynthesis,fabricating high-performance S-scheme heterojunction is regarded as a successful tactic to address energy and environmental issues.Herein,NH_(2)-MIL-125(Ti)/Zn_(0.5)Cd_(0.5)S/NiS(NMT...Inspired by natural photosynthesis,fabricating high-performance S-scheme heterojunction is regarded as a successful tactic to address energy and environmental issues.Herein,NH_(2)-MIL-125(Ti)/Zn_(0.5)Cd_(0.5)S/NiS(NMT/ZCS/NiS)S-scheme heterojunction with interfacial coordination bonds is successfully synthesized through in-situ solvothermal strategy.Notably,the optimal NMT/ZCS/NiS S-scheme heterojunction exhibits comparable photocatalytic H_(2)evolution(PHE)rate of about 14876.7μmol h^(−1)g^(−1)with apparent quantum yield of 24.2%at 420 nm,which is significantly higher than that of recently reported MOFs-based photocatalysts.The interfacial coordination bonds(Zn–N,Cd–N,and Ni–N bonds)accelerate the separation and transfer of photogenerated charges,and the NiS as cocatalyst can provide more catalytically active sites,which synergistically improve the photocatalytic performance.Moreover,theoretical calculation results display that the construction of NMT/ZCS/NiS S-scheme heterojunction also optimize the binding energy of active site-adsorbed hydrogen atoms to enable fast adsorption and desorption.Photoassisted Kelvin probe force microscopy,in-situ irradiation X-ray photoelectron spectroscopy,femtosecond transient absorption spectroscopy,and theoretical calculations provide sufficient evidence of the S-scheme charge migration mechanism.This work offers unique viewpoints for simultaneously accelerating the charge dynamics and optimizing the binding strength between the active sites and hydrogen adsorbates over S-scheme heterojunction.展开更多
Poly(isoprene-co-glycidyl methacrylate)epoxy macromolecules were synthesized via reversible addition-fragmentation chain transfer(RAFT)polymerization to act as interfacial mediators between talcum powder(Talc)and styr...Poly(isoprene-co-glycidyl methacrylate)epoxy macromolecules were synthesized via reversible addition-fragmentation chain transfer(RAFT)polymerization to act as interfacial mediators between talcum powder(Talc)and styrene-butadiene rubber(SBR)with the aim of improving the properties of SBR/Talc composites.The epoxy macromolecules were uniformly dispersed on the surface of Talc using the spray-drying method.Subse-quently,the modified Talc was utilized in the preparation of SBR composites.During hot vulcanization,isoprene double bonds could directly graft onto the rubber skeleton.Simultaneously,the epoxy groups opened the ring and formed covalent bonds with silanol.The interfacial covalent bonds were found to significantly enhance the dispersion of Talc and the interfacial interactions between SBR and Talc,as evidenced by scanning electron microscopy,cross-linking density measurements,and rubber processing analyzer tests.Differential scanning calorimetry results indicated that the number of interfacial covalent bonds and the content of glassy layers in the composites increased with the rise in GMA content and modified Talc.At equivalent filler loadings,epoxy macromolecules with 20 wt%and 34 wt%GMA increased the tensile strength by 31%and 49%,respectively.Concerning viscoelastic properties,composites containing interfacial covalent bonds exhibited superior stress relaxation and stress softening properties.展开更多
The rapid expansion of marine industries has created an urgent demand for advanced engineering materials with superior multifunctional performance.While Cu-Ni alloys demonstrate favorable stability and tribological ch...The rapid expansion of marine industries has created an urgent demand for advanced engineering materials with superior multifunctional performance.While Cu-Ni alloys demonstrate favorable stability and tribological characteristics,their practical applications are constrained by compromised thermal conductivity and insufficient mechanical strength due to the solid solution of a high amount of Ni in the Cu matrix.Cu-Ni matrix composites reinforced with hexagonal boron nitride(h-BN)have garnered significant attention due to their potential for tailored mechanical and thermal properties.However,challenges such as BN agglomerations in Cu-Ni matrix and poor interfacial bonding hinder their practical applications.To address these limitations,this study proposes an innovative fabrication strategy for boron nitride nanosheets(BNNSs)reinforced Cu-Ni composites by integrating the in situ synthesis of BNNSs on Cu powders via chemical vapor deposition with powder metallurgy.Benefited by the in situ strategy,BNNSs with high crystallinity distribute uniformly within the Cu matrix and have an intimate interfacial bonding without voids or other types of defects.Remarkably,the BNNSs/Cu-30%Ni composite achieves simultaneous enhancement in strength and ductility,exhibiting an ultimate tensile strength of 417 MPa and fracture elongation of 17.5%,representing 30%and 118%improvements over pure Cu-Ni alloys,respectively.This exceptional mechanical synergy originates from threefold strengthening mechanisms:grain refinement,mobile dislocation pinning,and efficient stress transfer via robust interfaces.The microstructural analysis confirms that homogenous distribution of BNNSs optimized stress distribution,mitigating strain localization in the composites.Fractographic examination demonstrates uniformly distributed dimples containing embedded BNNSs,indicative of effective crack bridging and deflection during failure.Furthermore,the composite possesses excellent corrosion resistance comparable to matrix alloys,while achieving 21.23%enhancement in thermal conductivity and 20%reduction in coefficient of friction.The scalable fabrication protocol successfully resolves longstanding challenges in BNNSs dispersion and interfacial bonding,offering a viable pathway for designing high-performance CMCs for marine applications.展开更多
Improving the thermal conductivity(TC)of diamond–metal composites has always been a significant challenge in the field of thermal management.In this paper,diamond/Al composites are systematically studied,and the infl...Improving the thermal conductivity(TC)of diamond–metal composites has always been a significant challenge in the field of thermal management.In this paper,diamond/Al composites are systematically studied,and the influence of the holding time(10–120 min)on interface structure and TC is discussed.The results of this research show that longterm thermal diffusion sintering can achieve dense interfacial bonding in diamond/Al composites,enhancing their TC.Diamond/Al composites with 50 vol%of 900μm diamond attain the highest TC value of 888.73 W·m^(-1)·K^(-1)under sintering conditions of 650?C,50 MPa,and 120 min—nearly 92%of the theoretical value predicted by the Maxwell model.This study establishes that high TC can be achieved through long-term thermal diffusion alone,without the need for complex diamond surface coating or substrate alloying.展开更多
基金supported by the Guangdong Major Project of Basic and Applied Basic Research(No.2020B0301030006)the Guangdong Basic and Applied Basic Research Foundation[Grant No.2021B1515120071]+1 种基金R.Shi would like to thank the financial support from the open research fund of Songshan Lake Materials Laboratory(2021SLABFK06)start-up funding from Harbin Institute of Technology(Shenzhen).
文摘Magnesium alloys have gained extensive applications across various industries,including aerospace,transportation,and civil construction,owing to their excellent combinations of high specific strength and stiffness[1].However,their lim-ited strength due to the lack of effective strengthening phases has hindered their broader industrial applications[2].Never-theless,it has been challenging to achieve significant strength-ening due to the restricted solubility of alloying elements in magnesium[3].Thus,more and more efforts have been made to explore the concept of secondary phase-reinforced magne-sium alloys[2,4,5],where the secondary phase acts as re-inforcing agents within the magnesium matrix,resembling a composite material.
基金co-supported by the National Natural Science Foundation of China(Nos.52105411,52105400and 52305420)the China Postdoctoral Science Foundation(No.2023M742830)Innovation Foundation for Doctor Dissertation of Northwestern Polytechnical University(No.CX2023008).
文摘In this study,a new linear friction welding(LFW)process,embedded LFW process,was put forward,which was mainly applied to combination manufacturing of long or overlong loadcarrying titanium alloy structural components in aircraft.The interfacial plastic flow behavior and bonding mechanism of this process were investigated by a developed coupling EulerianLagrangian numerical model using software ABAQUS and a novel thermo-physical simulation method with designed embedded hot compression specimen.In addition,the formation mechanism and control method of welding defects caused by uneven plastic flow were discussed.The results reveal that the plastic flow along oscillating direction of this process is even and sufficient.In the direction perpendicular to oscillation,thermo-plastic metals mainly flow downward along welding interface under coupling of shear stress and interfacial pressure,resulting in the interfacial plastic zone shown as an inverted“V”shape.The upward plastic flow in this direction is relatively weak,and only a small amount of flash is extruded from top of joint.Moreover,the wedge block and welding components at top of joint are always in un-steady friction stage,leading to nonuniform temperature field distribution and un-welded defects.According to the results of numerical simulation,high oscillating frequency combined with low pressure and small amplitude is considered as appropriate parameter selection scheme to improve the upward interfacial plastic flow at top of joint and suppress the un-welded defects.The results of thermo-physical simulation illustrate that continuous dynamic recrystallization(CDRX)induces the bonding of interface,accompanying by intense dislocation movement and creation of many low-angle grain boundaries.In the interfacial bonding area,grain orientation is random with relatively low texture density(5.0 mud)owing to CDRX.
基金Project(2011DFR50630)sponsored by the International S&T Cooperation of China
文摘The growth of intermetallic compounds at the interface between solid Al and Fe and the effects of intermetallic compound layers on the interfacial bonding of clad materials were investigated. The results showed that the interface between the solid Fe and Al formed by heat-treatment consisted of Fe2Al5 and FeAl3 intermetallic compound layers, which deteriorated the interfacial bonding strength. Fractures occurred in the intermetallic compound layer during the shear testing. The location of the fracture depended on the defects of microcracks or voids in the intermetallic compound layers. The microcracks in the intermetallic compound layer were caused by the mismatch of thermal expansion coefficients of materials during cooling, and the voids were consistent with the Kirkendall effect. The work will lay an important foundation for welding and joining of aluminum and steel, especially for fabrication of Al-Fe clad materials.
文摘Interfacial bonding in as deposited and annealed Co/C soft X ray multilayer structures is investigated by X ray photo electron spectroscopy (XPS).It is found that there is interdiffusion between cobalt and carbon in the as deposited Co/C multilayers,and this is confirmed by structure characterization using low angle X ray diffraction (LAXD).The calculation of the chemical shifts in Co C system based on Miedemas macroscopic atom model suggests that it is impossible to detect the chemical shift experimentally in the Co C compound,which is consistent with the XPS results.The presence of metallic carbide bonding is evidenced through the nature of the carbon bonding in survey taken at Co C and C Co interfaces of annealed samples.Our results also indicate that XPS is a direct method to probe the chemical bonding at the interfaces.
基金supported by the National Natural Science Foundation of China (No.50971020) National High-Tech Research and Development Program of China (No.2008AA03Z505)
文摘Cu-based and Cu-alloy-based diamond composites were made by high-pressure-high-temperature （HPHT） sintering with the aim of maximizing the thermal conductivity of the composites. Improvements in interfacial bonding strength and thermo-physical properties of the composites were achieved using an atomized copper alloy with minor additions of Co, Cr, 13, and Ti. The thermal conductivity （TC） oh- mined exhibited as high as 688 W.m-1.K-1, but also as low as 325 W.m-1.K-l. A large variation in TC can be rationalized by the discrepancy of diamond-matrix interfacial bonding. It was found from fractography that preferential bonding between diamond and the Cu-alloy matrix occurred only on the diamond {100} faces. EDS analysis and Raman spectra suggested that selective interfacial bonding may be attributed to amorphous carbon increasing the wettability between diamond and the Cu-alloy matrix. Amorphous carbon was found to significantly affect the TC of the composite by interface modification.
基金the National Natural Science Foundation of China(No.51521061)the Defense Industrial Technology Development Program(No.A1120133026)+2 种基金the Doctoral Fund of Ministry of Education of China(No.20126102110022)the“111”Project of China(No.B08040)the Research Fund of the State Key Laboratory of Solidification Processing(NWPU)(No.85-TZ-2013)
文摘7075 aluminum billets were fabricated by micro droplet deposition manufacturing technique, and the influence of interracial bonding between metal droplets on the tensile properties was studied. Three sets of samples were manufactured under different temperature conditions, and their mechanical properties were compared. The results show that the temperature of the metal droplets and substrate significantly affect the tensile strength of the sample. Moreover, with proper temperature setting, the 7075 aluminum billets manufactured by micro metal droplet deposition could achieve very good mechanical properties with a tensile strength of 373 MPa and an elongation of 9.95%, which are very similar to those of an ex truded sample. Moreover, a metallurgical bonding diagram based on numerical calculations of interfacial temperature was established to predict the interfacial bonding state. In addition, the fracture morphologies of these specimens were observed. It is indicated that there was a significant transformation of failure mechanism with the improvement of metallurgical bonding, which agreed well with the numerical results.
基金the National Natural Science Foundation of China[grant number 51571080].
文摘In this study,an overcasting process followed by a low-temperature(200°C)annealing schedule has been developed to bond magnesium to aluminum alloys.ProCAST software was used to optimize the process parameters during the overcasting process which lead to Mg/Al bimetallic structures to be successfully produced without formation of Mg-Al intermetallic phases.Detailed microstructure evolution during annealing,including the formation and growth of Al-Mg interdiffusion layer and intermetallic phases(Al12Mg17 and Al3Mg2),was experimentally observed for the first time with direct evidence,and predicted using Calculation of Phase Diagrams(CALPHAD)modeling.Maximum interfacial strength was achieved when the interdiffusion layer formed at the Mg/Al interface reached a maximum thickness the without formation of brittle intermetallic compounds.The precise diffusion modeling of the Mg/Al interface provides an efficient way to optimize and control the interfacial microstructure of Mg/Al bimetallic structures for improved interfacial bonding.
基金the financial support from Iran National Science Foundation (INSF) under grant number 95822903
文摘A facile and innovative method to improve bonding between the two parts of compound squeeze cast Al/Al-4.5 wt.%Cu macrocomposite bimetals was developed and its effects on microstructure and mechanical properties of the bimetal were investigated.A special concentric groove pattern was machined on the top surface of the insert(squeeze cast Al-4.5 wt.%Cu) and its effects on heat transfer,solidification and distribution of generated stresses along the interface region of the bimetal components were simulated using ProCAST and ANSYS softwares and experimentally verified. Simulation results indicated complete melting of the tips of the surface grooves and local generation of large stress gradient fields along the interface. These are believed to result in rupture of the insert interfacial aluminum oxide layer facilitating diffusion bonding of the bimetal components. Microstructural evaluations confirmed formation of an evident transition zone along the interface region of the bimetal. Average thickness of the transition zone and tensile strength of the bimetal were significantly increased to about 375 μm and 54 MPa, respectively, by applying the surface pattern.The proposed method is an affordable and promising approach for compound squeeze casting of Al-Al macrocomposite bimetals without resort to any prior cost and time intensive chemical or coating treatments of the solid insert.
基金funded by the Engineering and Physical Science Research Council(EPSRC),UK(Grant Nos.EP/P027563/1 and EP/M028267/1)the Science and Technology Facilities Council(STFC)(Grant No.ST/R006105/1)the Bridging for Innovators Programme of Department for Business,Energy and Industrial Strategy(BEIS),UK.
文摘Tungsten(W)and stainless steel(SS)are well known for the high melting point and good corrosion resistance respectively.Bimetallic W-SS structures would offer potential applications in extreme environments.In this study,a SS→W→SS sandwich structure is fabricated via a special laser powder bed fusion(LPBF)method based on an ultrasonic-assisted powder deposition mechanism.Material characterization of the SS→W interface and W→SS interface was conducted,including microstructure,element distribution,phase distribution,and nano-hardness.A coupled modelling method,combining computational fluid dynamics modelling with discrete element method,simulated the melt pool dynamics and solidification at the material interfaces.The study shows that the interface bonding of SS→W(SS printed on W)is the combined effect of solid-state diffusion with different elemental diffusion rates and grain boundary diffusion.The keyhole mode of the melt pool at the W→SS(W printed on SS)interface makes the pre-printed SS layers repeatedly remelted,causing the liquid W to flow into the sub-surface of the pre-printed SS through the keyhole cavities realizing the bonding of the W→SS interface.The above interfacial bonding behaviours are significantly different from the previously reported bonding mechanism based on the melt pool convection during multiple material LPBF.The abnormal material interfacial bonding behaviours are reported for the first time.
基金supported by the National Natural Science Foundation of China(Nos.51805359 and 51804215)the China Postdoctoral Science Foundation(No.2018M631772)+4 种基金the Natural science foundation of Shanxi Province,China(No.201901D211015)the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi Province,China(STIP)(No.2019L0333)the Major Program of National Natural Science Foundation of China(No.U1710254)the Key Projects of Shanxi province Key Research and Development Plan,China(No.201703D111003)the Scientific and Technological Progress of Shanxi province Colleges and Universities,China(No.2017132)。
文摘Interfacial bonding,microstructures,and mechanical properties of an explosively-welded H68/AZ31B clad plate were systematically studied.According to the results,the bonding interface demonstrated a“wavy-like”structure containing three typical zones/layers:(1)diffusion layer adjacent to the H68 brass plate;(2)solidification layer of melted metals at the interface;(3)a layer at the side of AZ31B alloy that experienced severe deformation.Mixed copper,CuZn_(2),andα-Mg phases were observed in the melted-solidification layer.Regular polygonal grains with twins were found at the H68 alloy side,while fine equiaxed grains were found at the AZ31B alloy side near the interface due to recrystallization.Nanoindentation results revealed the formation of brittle intermetallic CuZn_(2) phases at the bonding interface.The interface was bonded well through metallurgical reactions due to diffusion of Cu,Zn,and Mg atoms across the interface and metallurgic reaction of partially melted H68 and AZ31B alloys.
文摘The main Iimitation to the toughening of the α-Al2O3/Ni composite is the poor bonding atthe interface. which causes the nickel particles to be pulled-out during crack propagation with-out obvious plastic deformation. A proper control of oxygen content at the Al2O3-Ni interfacecan promote wetting at the intedece, and produce a mechanically interlocked and chemically strengthened intedece, causing most of the nickel particles to be stretched to failure and to expe-rience severe plastic deformation during crack propagation in the composite. Fracture toughnesstesting using a modified double cantilever beam method with in situ observation of crack prop-agation in a scanning electron microscope shows that the composite with the strengthenedinterface has a more desirable R-curve behaviour and a higher fracture toughness value than thenormal composite.
基金supported by the National Natural Science Foundation of China(No.62004143)the Key R&D Program of Hubei Province(No.2022BAA084)the Major Project of Natural Science Foundation of Jiangsu Universities,China(No.23KJA150010)。
文摘Photocatalytic overall pure water splitting is a promising method for generating green hydrogen energy under mild conditions.However,this process is often hindered by sluggish electron-hole separation and transport.To address this,a step-scheme(S-scheme)B-doped N-deficient C_(3)N_(4)/O-doped C_(3)N_(5)(BN-C_(3)N_(4)/O-C_(3)N_(5))heterojunction with interfacial B-O bonds has been constructed.Utilizing Pt and Co(OH)_(2) as co-catalysts,BN-C_(3)N_(4)/O-C_(3)N_(5) S-scheme heterojunction demonstrates significantly enhanced photocatalytic activity for overall pure water splitting under visible light,achieving H_(2) and O_(2) evolution rates of 40.12 and 19.62μmol/h,respectively.Systematic characterizations and experiments revealed the performance-enhancing effects of the enhanced built-in electric field and the interfacial B-O bonding.Firstly,the strengthened built-in electric field provides sufficient force for rapid interfacial electron transport.Secondly,by reducing the transport energy barrier and transfer distance,the interfacial B-O bonds facilitate rapid recombination of electrons and holes with relatively low redox potential via the S-scheme charge-transfer route,leaving the high-potential electrons and holes available for H^(+)reduction and OH^(-)oxidation reactions.Overall,the photocatalytic efficiency of BN-C_(3)N_(4)/O-C_(3)N_(5) S-scheme heterojunction was significantly improved,making it a promising approach for green hydrogen production through overall pure water splitting.
基金supported by the National Key Research and Development Program of China [2022YFB4600102]National Natural Science Foundation of China [52125505,U20A20297,52275561,U23A20637].
文摘Multi-material additive manufacturing(MMAM)takes full advantage of the ability to arbitrarily place materials of addi-tive manufacturing technology,enabling immense design free-dom and functional print capabilities.Among MMAM technologies,projection stereolithography(PSL)exhibits a great balance of high resolution and fast printing speed.However,fabrication accuracy of multi-material PSL is hin-dered by large overcure used to strengthen interfacial bond-ing weakened by chemical affinity and material-exchange process.We present a novel multi-step exposure method for multi-material PSL process to overcome this shortcoming.Firstly,the whole layer is moderately exposed producing over-cure of single-material PSL level to generate geometries.Then weakened interfaces are strengthened individually with addi-tional steps of exposure.The multi-step exposure is integrated into the already efficient materials printing order of multi-material PSL process.Curing depth and overcure of photocur-able resins are modeled and characterized.Exposure required to achieve sufficient interfacial bonding of single-material interfaces built through material-exchange process and multi-material interfaces with altering materials printing order is determined with tensile tests.Microfluidic channels are used to compare fabrication accuracy of traditional single-step exposure and our multi-step exposure method.This method can be widely applied in multi-material PSL to improve fabri-cation accuracy in a variety of applications including micro-fluidic devices.
基金supported by the NSFC-Zhejiang Joint Fund for Integration of Industrialization and Diversification(No.U1809214)the Natural Science Foundation of Zhejiang Province(Nos.LTGN23E080001 and LY20E080014)+1 种基金the Science and Technology Project of Zhoushan(No.2022C41011)the National Natural Science Foundation of China(No.22201251).
文摘Devising robust S-scheme photocatalysts is of central importance for achieving high-efficient micropollu-tant decontamination.However,the conscious optimization of S-scheme system with high performance remains a prime challenge.Herein,carbon quantum dots(CDs)and Mn_(0.5)Cd_(0.5)S(MCS)are mounted on BiOBr(BOB)microspheres,establishing an advanced S-scheme heterojunction with interfacial Bi-S bond.The interfacial Bi-S bonds function as superb channels at atomic-scale to abate the energy barrier for S-scheme charge transportation.Meanwhile,CDs serve as electron collectors to preserve highly reductive electrons from MCS,further augmenting the spatial separation of photo-carriers.Therefore,the optimized CDs/MCS/BOB(MBC)heterojunction manifests significantly strengthened tetracycline hydrochloride(TC)destruction activity and its reaction rate constant is approximately 3.1,2.2,2.1,and 1.5 folds that than that of MCS,BOB,BOB/CDs and MCS/BOB.In addition,MBC exhibits high stability and significant resistance to environmental interferences.The toxicology evaluation confirms the effective abatement of toxicity of TC after treatment.This achievement demonstrates the benefits of CDs-optimized S-scheme photosystems with chemical bonds for photocatalytic water decontamination.
基金supported by the National Natural Science Foundation of China(Nos.22078118 and 42277219)the Natural Science Foundation of Guangdong Province,China(No.2023A1515010740).
文摘A novel photocatalytic cocatalyst, MoC quantum dots integrated into N-doped carbon microflowers (MoC–NC), was synthesized, establishing a key Mo–N interfacial bond. The Mo–N bond's regulation was achieved by adjusting the pH of Mo-polydopamine precursor solutions. A composite photocatalyst, MoC–NC/CdS (MNS), was formed by in situ growth of nano-CdS on MoC–NC. The pH during synthesis, crucial for Mo–N bond formation, significantly influenced Cr(Ⅵ) reduction and H_(2) evolution performance. The optimal MNS, created at pH 9.0, demonstrated 99.2% reduction efficiency for Cr(Ⅵ) in 20 min and H_(2) evolution rate of 11.4 mmol g^(-1) h^(-1) over 3 h, outperforming Pt/CdS. Mechanistic studies and density functional theory revealed MoC–NC's role in enhancing light absorption, reaction kinetics, and electron transport, attributing to its ultra-small quantum dots and abundant Mo–N bonds.
基金Jiangsu Provincial Department of Science and Technology,Grant/Award Number:BK20201190Fundamental Research Funds for“Young Talent Support Plan”of Xi'an Jiaotong University,Grant/Award Number:HG6J003+1 种基金“1000-Plan program”of Shaanxi Province and the Velux Foundations through the research center V-Sustain,Grant/Award Number:9455National Key R&D Program of China,。
文摘The use of lithium-sulfur batteries under high sulfur loading and low electrolyte concentrations is severely restricted by the detrimental shuttling behavior of polysulfides and the sluggish kinetics in redox processes.Two-dimensional(2D)few layered black phosphorus with fully exposed atoms and high sulfur affinity can be potential lithium-sulfur battery electrocatalysts,which,however,have limitations of restricted catalytic activity and poor electrochemical/chemical stability.To resolve these issues,we developed a multifunctional metal-free catalyst by covalently bonding few layered black phosphorus nanosheets with nitrogen-doped carbon-coated multiwalled carbon nanotubes(denoted c-FBP-NC).The experimental characterizations and theoretical calculations show that the formed polarized P-N covalent bonds in c-FBP-NC can efficiently regulate electron transfer from NC to FBP and significantly promote the capture and catalysis of lithium polysulfides,thus alleviating the shuttle effect.Meanwhile,the robust 1D-2D interwoven structure with large surface area and high porosity allows strong physical confinement and fast mass transfer.Impressively,with c-FBP-NC as the sulfur host,the battery shows a high areal capacity of 7.69 mAh cm^(−2) under high sulfur loading of 8.74 mg cm^(−2) and a low electrolyte/sulfur ratio of 5.7μL mg^(−1).Moreover,the assembled pouch cell with sulfur loading of 4 mg cm^(−2) and an electrolyte/sulfur ratio of 3.5μL mg^(−1) shows good rate capability and outstanding cyclability.This work proposes an interfacial and electronic structure engineering strategy for fast and durable sulfur electrochemistry,demonstrating great potential in lithium-sulfur batteries.
文摘Inspired by natural photosynthesis,fabricating high-performance S-scheme heterojunction is regarded as a successful tactic to address energy and environmental issues.Herein,NH_(2)-MIL-125(Ti)/Zn_(0.5)Cd_(0.5)S/NiS(NMT/ZCS/NiS)S-scheme heterojunction with interfacial coordination bonds is successfully synthesized through in-situ solvothermal strategy.Notably,the optimal NMT/ZCS/NiS S-scheme heterojunction exhibits comparable photocatalytic H_(2)evolution(PHE)rate of about 14876.7μmol h^(−1)g^(−1)with apparent quantum yield of 24.2%at 420 nm,which is significantly higher than that of recently reported MOFs-based photocatalysts.The interfacial coordination bonds(Zn–N,Cd–N,and Ni–N bonds)accelerate the separation and transfer of photogenerated charges,and the NiS as cocatalyst can provide more catalytically active sites,which synergistically improve the photocatalytic performance.Moreover,theoretical calculation results display that the construction of NMT/ZCS/NiS S-scheme heterojunction also optimize the binding energy of active site-adsorbed hydrogen atoms to enable fast adsorption and desorption.Photoassisted Kelvin probe force microscopy,in-situ irradiation X-ray photoelectron spectroscopy,femtosecond transient absorption spectroscopy,and theoretical calculations provide sufficient evidence of the S-scheme charge migration mechanism.This work offers unique viewpoints for simultaneously accelerating the charge dynamics and optimizing the binding strength between the active sites and hydrogen adsorbates over S-scheme heterojunction.
基金financially supported the Key Research and Development Project of Anhui Province(2022a05020009)the Science and Technology Plan Project of Huangshan City(2021KC-05)the Engineering Research Project of Anhui Polytechnic University(HX-2021-09-007).
文摘Poly(isoprene-co-glycidyl methacrylate)epoxy macromolecules were synthesized via reversible addition-fragmentation chain transfer(RAFT)polymerization to act as interfacial mediators between talcum powder(Talc)and styrene-butadiene rubber(SBR)with the aim of improving the properties of SBR/Talc composites.The epoxy macromolecules were uniformly dispersed on the surface of Talc using the spray-drying method.Subse-quently,the modified Talc was utilized in the preparation of SBR composites.During hot vulcanization,isoprene double bonds could directly graft onto the rubber skeleton.Simultaneously,the epoxy groups opened the ring and formed covalent bonds with silanol.The interfacial covalent bonds were found to significantly enhance the dispersion of Talc and the interfacial interactions between SBR and Talc,as evidenced by scanning electron microscopy,cross-linking density measurements,and rubber processing analyzer tests.Differential scanning calorimetry results indicated that the number of interfacial covalent bonds and the content of glassy layers in the composites increased with the rise in GMA content and modified Talc.At equivalent filler loadings,epoxy macromolecules with 20 wt%and 34 wt%GMA increased the tensile strength by 31%and 49%,respectively.Concerning viscoelastic properties,composites containing interfacial covalent bonds exhibited superior stress relaxation and stress softening properties.
基金financial support of the National Key R&D Program of China(No.SQ2024YFA1200082)the National Natural Science Foundation of China(No.52371013)the Natural Science Foundation of Tianjin City(No.22JCZDJC00020).
文摘The rapid expansion of marine industries has created an urgent demand for advanced engineering materials with superior multifunctional performance.While Cu-Ni alloys demonstrate favorable stability and tribological characteristics,their practical applications are constrained by compromised thermal conductivity and insufficient mechanical strength due to the solid solution of a high amount of Ni in the Cu matrix.Cu-Ni matrix composites reinforced with hexagonal boron nitride(h-BN)have garnered significant attention due to their potential for tailored mechanical and thermal properties.However,challenges such as BN agglomerations in Cu-Ni matrix and poor interfacial bonding hinder their practical applications.To address these limitations,this study proposes an innovative fabrication strategy for boron nitride nanosheets(BNNSs)reinforced Cu-Ni composites by integrating the in situ synthesis of BNNSs on Cu powders via chemical vapor deposition with powder metallurgy.Benefited by the in situ strategy,BNNSs with high crystallinity distribute uniformly within the Cu matrix and have an intimate interfacial bonding without voids or other types of defects.Remarkably,the BNNSs/Cu-30%Ni composite achieves simultaneous enhancement in strength and ductility,exhibiting an ultimate tensile strength of 417 MPa and fracture elongation of 17.5%,representing 30%and 118%improvements over pure Cu-Ni alloys,respectively.This exceptional mechanical synergy originates from threefold strengthening mechanisms:grain refinement,mobile dislocation pinning,and efficient stress transfer via robust interfaces.The microstructural analysis confirms that homogenous distribution of BNNSs optimized stress distribution,mitigating strain localization in the composites.Fractographic examination demonstrates uniformly distributed dimples containing embedded BNNSs,indicative of effective crack bridging and deflection during failure.Furthermore,the composite possesses excellent corrosion resistance comparable to matrix alloys,while achieving 21.23%enhancement in thermal conductivity and 20%reduction in coefficient of friction.The scalable fabrication protocol successfully resolves longstanding challenges in BNNSs dispersion and interfacial bonding,offering a viable pathway for designing high-performance CMCs for marine applications.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12274372 and 12274373)the Major Science and Technology Projects of Henan Province(Grant No.231100230300)。
文摘Improving the thermal conductivity(TC)of diamond–metal composites has always been a significant challenge in the field of thermal management.In this paper,diamond/Al composites are systematically studied,and the influence of the holding time(10–120 min)on interface structure and TC is discussed.The results of this research show that longterm thermal diffusion sintering can achieve dense interfacial bonding in diamond/Al composites,enhancing their TC.Diamond/Al composites with 50 vol%of 900μm diamond attain the highest TC value of 888.73 W·m^(-1)·K^(-1)under sintering conditions of 650?C,50 MPa,and 120 min—nearly 92%of the theoretical value predicted by the Maxwell model.This study establishes that high TC can be achieved through long-term thermal diffusion alone,without the need for complex diamond surface coating or substrate alloying.
