Titanium plates with a Ti−O solid solution surface-hardened layer were cold roll-bonded with 304 stainless steel plates with high work hardening rates.The evolution and mechanisms affecting the interfacial bonding str...Titanium plates with a Ti−O solid solution surface-hardened layer were cold roll-bonded with 304 stainless steel plates with high work hardening rates.The evolution and mechanisms affecting the interfacial bonding strength in titanium/stainless steel laminated composites were investigated.Results indicate that the hardened layer reduces the interfacial bonding strength from over 261 MPa to less than 204 MPa.During the cold roll-bonding process,the hardened layer fractures,leading to the formation of multi-scale cracks that are difficult for the stainless steel to fill.This not only hinders the development of an interlocking interface but also leads to the presence of numerous microcracks and hardened blocks along the nearly straight interface,consequently weakening the interfacial bonding strength.In metals with high work hardening rates,the conventional approach of enhancing interface interlocking and improving interfacial bonding strength by using a surface-hardened layer becomes less effective.展开更多
In situ growth of co-catalysts on BiVO_(4)(BVO)to enhance photoelectrochemical(PEC)water splitting performance has been extensively reported.However,the understanding of the synergistic effects among various elements,...In situ growth of co-catalysts on BiVO_(4)(BVO)to enhance photoelectrochemical(PEC)water splitting performance has been extensively reported.However,the understanding of the synergistic effects among various elements,especially at the interface between the semiconductor and cocatalyst,has received insufficient attention.In this study,we report a Co,Ni and Mn trimetallic fluoride-modified BVO photoanode featuring a unique interfacial chemical bond(V-F).Under AM 1.5 G illumination,an exciting photocurrent density of 6.05 mA cm^(-2)was achieved at 1.23 V vs.RHE by the integrated BVO/CoNi_(0.18)Mn_(0.12)(OH)_(x)F photoanode and over 98%of the initial photocurrent was maintained after 10 h of photoelectrolysis.Control experiments and theoretical calculations demonstrate that the V-F interfacial bond stabilizes the Co^(2+)active sites.It serves as a transmission gear,interlinking the migration of interfacial charge and the regeneration of cocatalyst,endowing the photoanode with significant activity and stability.Furthermore,we have systematically elucidated the role of the individual Co,Ni,and Mn components in the synergistic cocatalyst layer.The interfacial modification provides novel insights into developing advanced photoanodes towards PEC water splitting.展开更多
Multimaterial digital light processing(DLP)three-dimensional(3D)printing technology provides unique advantages in the field of multi material additive manufacturing(MM AM)with its high resolution and rapid shaping cap...Multimaterial digital light processing(DLP)three-dimensional(3D)printing technology provides unique advantages in the field of multi material additive manufacturing(MM AM)with its high resolution and rapid shaping capabilities based on photopolymerization.However,owing to differences in the curing behavior and physical properties of different materials,multimaterial DLP 3D printing faces challenges such as insufficient interfacial bonding strength and unstable mechanical properties.In this study,two resins were integrated by multimaterial DLP 3D printing technology,and the effects of different layer thicknesses and exposure times on the interfacial bonding strength and morphology of the multimaterials were systematically investigated.The interfacial bonding mechanisms of the two resins was analyzed.It was found that increasing the exposure time can improve the interfacial bonding strength between materials,but certain limitations exist.A mathematical model relating the interfacial bonding strength to the exposure time and layer thickness was developed,and optimal process parameters were determined using optimization algorithms.A variable-parameter printing strategy for the interface was proposed to further improve the performance of printed parts.The maximum tensile strength of the multimaterial samples(44.43 MPa)using this strategy reached that of single-material parts(45 MPa),validating the feasibility of this strategy.This provides guidance for multimaterial DLP 3D printing processes and offers valuable insights for the future additive manufacturing of high-performance multimaterial components.展开更多
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
The unclear interfacial characteristics of Ag/Cu interface during diffusion welding limit the improvement of mechanical properties of Ag/Cu bimetallic strips.The growth orientation and evolution of Ag and Cu crystals ...The unclear interfacial characteristics of Ag/Cu interface during diffusion welding limit the improvement of mechanical properties of Ag/Cu bimetallic strips.The growth orientation and evolution of Ag and Cu crystals between Ag and Cu strips were investigated by electron backscatter diffraction(EBSD)analysis,and the interfacial properties of various Ag/Cu interfacial configurations were calculated using first-principles calculations to elucidate the diversified interfacial characteristics.Three interface bonding states,including Ag(100)/Cu(100),Ag(110)/Cu(110)and Ag(111)/Cu(111),were preferentially formed in Ag/Cu bimetallic strips during roll bonding.The intensity of Ag(100)/Cu(100)interface increases with the increasing deformation amounts during cold rolling,accompanied by the decreased intensity of Ag(110)/Cu(110)and Ag(111)/Cu(111)interfaces.The largest adsorption work and lowest interface energy of Ag(100)/Cu(100)interface at the“center”position reveal the transition from Ag(110)/Cu(110)and Ag(111)/Cu(111)interfaces to Ag(100)/Cu(100)interface.展开更多
The bonding interface characteristic and shear strength of diffusion bonded Ti-17 titanium alloy at different bonding time were investigated. The results show that the average size of voids decreases while the amount ...The bonding interface characteristic and shear strength of diffusion bonded Ti-17 titanium alloy at different bonding time were investigated. The results show that the average size of voids decreases while the amount of voids decreases after increasing to the maximum value with the increasing bonding time. The irregular void with a scraggly edge tends to an ellipse void with smooth surface and then changes to a tiny void with round shape. The grains across bonding interface occur at bonding time of 60 min. The shear strength of bond increases with increasing bonding time, and the highest shear strength of bond is 887.4 MPa at 60 min. The contribution of plastic deformation on the void closure and the increase of shear strength is significant even though the action time of plastic deformation is short.展开更多
A Fe/Al clad tube was prepared by explosive welding.Then the bonding characteristic of the interface was investigated by compression,flattening and compression-shear test.The test results exhibit that the clad tubes p...A Fe/Al clad tube was prepared by explosive welding.Then the bonding characteristic of the interface was investigated by compression,flattening and compression-shear test.The test results exhibit that the clad tubes possessing good bonding interface have higher shear strength than that of pure aluminum and can bear both axial and radial deformation.The original interface between aluminum layer and ferrite layer was observed by scanning electron microscopy（SEM）.The results show that the clad tubes with good bonding properties possess the interface in wave and straight shape.The Fe/Al clad tube was used to manufacture the T-shape by hydro-bulging.It is found that the good-bonding interface of the Fe/Al clad tube plays a dominant role in the formation of the T-shape.展开更多
The effect of grain size of primary α phase on the bonding interface characteristic and shear strength of bond was investigated in the press bonding of Ti-6Al-4V alloy. The quantitative results show that the average ...The effect of grain size of primary α phase on the bonding interface characteristic and shear strength of bond was investigated in the press bonding of Ti-6Al-4V alloy. The quantitative results show that the average size of voids increases from 0.8 to 2.6 μm and the bonding ratio decreases from 90.9% to 77.8% with an increase in grain size of primary α phase from 8.2 to 16.4 μm. The shape of voids changes from the tiny round to the irregular strip. The highest shear strength of bond can be obtained in the Ti-6Al-4V alloy with a grain size of 8.2 μm. This is contributed to the higher ability of plastic flow and more short-paths for diffusion in the alloy with smaller grain size of primary α phase, which promote the void closure process and the formation of α/β grains across bonding interface.展开更多
AA4045/AA3003 cladding billet was prepared by direct chill semi-continuous casting process. The macrostructures, microstructures, temperature distribution, compositions distribution and the mechanical properties at th...AA4045/AA3003 cladding billet was prepared by direct chill semi-continuous casting process. The macrostructures, microstructures, temperature distribution, compositions distribution and the mechanical properties at the bonding interface were investigated in detail. The results show that the cladding billet with few defects could be obtained by semi-continuous casting process. At the interface, diffusion layer of about 10μm on average formed between the two alloys due to the diffusion of alloy elements in the temperature range from 596 to 632 °C. From the side of AA4045 to the side of AA3003, the Si content has a trend to decrease, while the Mn content has a trend to increase gradually. Tensile strength of the cladding billet reaches 103.7 MPa, the fractured position is located on the AA3003 side, and the shearing strength is 91.1 MPa, revealing that the two alloys were combined metallurgically by mutual diffusion of alloy elements.展开更多
Due to its superior nanoscale properties,cobalt(Co)is highly desirable for ultrahigh-density 3D integration into materials through metal/dielectric hybrid bonding.However,this process is very challenging through Co/Si...Due to its superior nanoscale properties,cobalt(Co)is highly desirable for ultrahigh-density 3D integration into materials through metal/dielectric hybrid bonding.However,this process is very challenging through Co/SiO_(2)hybrid bonding,as very hydrophilic SiO_(2)surfaces are needed for bonding during dehydration reactions and oxidation of the Co surfaces must be avoided.Additionally,the substantial coefficient of thermal expansion mismatch between the robust capping layers(Co and SiO_(2)layers)necessitates hybrid bonding with minimal thermal input and compression.In this study,we introduce a ternary plasma activation strategy employing an Ar/NH_(3)/H_(2)O gas mixture to facilitate Co/SiO_(2)hybrid bonding at temperatures as low as~200℃,which is markedly lower than the melting point of Co(~1500℃).Intriguingly,non-oxide metallization at the Co-Co interface can be realized without the hindrance of a bonding barrier,thereby reducing the electrical resistance by over 40%and compression force requirements.Moreover,the enhancement in the SiO_(2)surface energy through active group terminations fosters extensive interfacial hydration and strengthens the mechanical properties.This research paves the way for fine-tuning bonding surfaces using a material-selective strategy which should advance metal/dielectric hybrid bonding for future integration applications.展开更多
A hot compression bonding process was developed to prepare a novel laminated composite consisting of high-Cr cast iron （HCCI） as the inner layer and low carbon steel （LCS） as the outer layers on a Gleeble 3500 the...A hot compression bonding process was developed to prepare a novel laminated composite consisting of high-Cr cast iron （HCCI） as the inner layer and low carbon steel （LCS） as the outer layers on a Gleeble 3500 ther- momechanicat simulator at a temperature of 950 ℃ and a strain rate of 0. 001 s 1. Interfacial bond quality and hot deformation behaviour of the laminate were studied by mierostructural characterisation and mechanical tests. Experi- mental results show that the metallurgical bond between the constituent metals was achieved under the proposed bonding conditions without discernible defects and the formation of interlayer or intermetallic layer along the inter- face. The interfacial bond quality is excellent since no deterioration occurred around the interface which was deformed by Vickers indentation and compression test at room temperature with parallel loading to the interface. After well cladding by the LCS, the brittle HCCI can be severely deformed （about 57 % of reduction） at high temperature with crack-free. This significant improvement should be attributed to the decrease of crack sensitivity due to stress relief by soft claddings and enhanced flow property of the HCCI by simultaneous deformation with the LCS.展开更多
The study of the shear behavior of bonded rock-cement interface is important for understanding the strength and stability of grouted rock masses.This research aims to reveal the failure mechanism behind the shear prop...The study of the shear behavior of bonded rock-cement interface is important for understanding the strength and stability of grouted rock masses.This research aims to reveal the failure mechanism behind the shear property of bonded rock-cement interfaces.For the study,sandstone and granite joint blocks with specific morphology were fabricated by using a three-dimensional(3D)engraving technique.Bonded rock-cement joints with asperity inclination angles of 15°,30°,and 45°were prepared.Shear tests were performed on these bonded rock-cement joints to investigate the shear response and failure modes considering the effect of applied normal stress and interface morphology.Meanwhile,the two-dimensional particle flow code(PFC2D)was utilized to model the entire shear process of bonded rock-cement interfaces.The macroscopic shear behavior and mesoscopic failure mechanism were comprehensively investigated by the laboratory test and numerical simulation.The results showed that the shear stress-displacement curves of bonded rock-cement joints exhibit two distinct peaks,and the shear stress evolution can be categorized into four stages including elastic growth,rapid stress drop,secondary stress growth,and progressive softening.Significantly,the number of acoustic emission events also exhibits two distinct peaks related to the double peak of the shear stress curves.The failure of bonded rock-cement interfaces is mainly induced by shear fractures,while the failure of rock and cement blocks is primarily caused by tensile fractures.The number of shear cracks in the bonded rock-cement interfaces reaches the peak when the shear stress reaches the primary peak;whereas as the shear stress continuously approaches the residual stage,the fracture of the bonded rock-cement joints is primarily characterized by tensile cracks in the blocks.展开更多
The anchoring capacity of the anchor cable is closely related to the bonding length and radial pressure conditions.Through field pull-out tests,theoretical analysis,numerical simulation,and industrial tests,this study...The anchoring capacity of the anchor cable is closely related to the bonding length and radial pressure conditions.Through field pull-out tests,theoretical analysis,numerical simulation,and industrial tests,this study clarifies the relationship between radial pressure and bonding length for the ultimate pullout force and reveals the microscopic failure process of the resin-rock interface in the anchoring system.The results show that the ultimate load increases with the increase of bonding length in three different stages:rapid,slow,and uniform growth.The new mechanical model developed considering radial pressure describes the inverse relationship between radial pressure and the plastic zone on the bonding section,and quantifies the reinforcing effect of confining pressure on the anchoring force.During the pull-out process of the anchor cable,the generation of failure cracks is in the order of orifice,bottom,and middle of the hole.Radial pressure can effectively enhance the ultimate pull-out force,alleviate the oscillation increase of pull-out force,and inhibit resin cracking,but will produce an external crushing zone.It also reveals the synergistic effect between bonding length and radial pressure,and successfully carries out industrial tests of anchor cable support,which ensures the stability of the stope roof and provides an important reference for the design of anchor cable support in deep high-stress mines.展开更多
The effect of temperature on interface microstructure and shear strength of 1420 A1-Li alloy and 7B04 A1 alloy composite plates prepared by diffusion bonding were investigated. The results indicate the optimum tempera...The effect of temperature on interface microstructure and shear strength of 1420 A1-Li alloy and 7B04 A1 alloy composite plates prepared by diffusion bonding were investigated. The results indicate the optimum temperature for bonding the composite plates is 520℃, a sound bonding interface without continuous intermetallic compound layers and interfacial voids is obtained, and the shear strength value of bond joints can be as high as 190 MPa. An interfacial transition zone is formed due to the alloying elements mutual diffusion during the bonding process. Meanwhile, the effect of temperature on diffusion of alloying elements and interface reaction were discussed in detail, the results show that the higher temperature can increase the diffusion of alloying elements fluxes across the bonding interface, which can accelerate the closure of interfacial voids; meanwhile, when Mg atoms diffuse across the bonding interface, it can react with and break up the surface oxide films into discrete particles, and the removal of interface oxides increases the metal to metal bond areas and improves the bond quality.展开更多
This article introduces an element diffusion behavior model for a titanium/steel explosive clad plate characterized by a typical curved interface during the heat-treatment process. A series of heat-treatment experimen...This article introduces an element diffusion behavior model for a titanium/steel explosive clad plate characterized by a typical curved interface during the heat-treatment process. A series of heat-treatment experiments were conducted in the temperature range from 750℃ to 950℃, and the effects of heat-treatment parameters on the microstructural evolution and diffusion behavior were investigated by optical microscopy, scanning electron microscopy, X-ray diffraction analysis, and electron-probe microanalysis. Carbon atoms within the steel matrix were observed to diffuse toward the titanium matrix and to aggregate at the bonding interface at 850℃ or lower; in contrast, when the temperature exceeded 850℃, the mutual diffusion of Ti and Fe occurred, along with the diffusion of C atoms, resulting in the for- marion of Ti-Fe intermetallics （Fe2Ti/FeTi）. The diffusion distances of C, Ti, and Fe atoms increased with increasing heating temperature and/or holding time. On the basis of this diffusion behavior, a novel diffusion model was proposed. This model considers the effects of various factors, including the curvature radius of the curved interface, the diffusion coefficient, the heating temperature, and the holding rime. The experimental results show good agreement with the calculated values. The proposed model could clearly provide a general prediction of the elements＇ diffusion at both straight and curved interfaces.展开更多
Cu/Al bar clad material was fabricated by a drawing process and a subsequent heat treatment.During these processes,intermetallic compounds have been formed at the interface of Cu/Al and have affected its bonding prope...Cu/Al bar clad material was fabricated by a drawing process and a subsequent heat treatment.During these processes,intermetallic compounds have been formed at the interface of Cu/Al and have affected its bonding property.Microstructures of Cu/Al interfaces were observed by OM,SEM and EDX Analyser in order to investigate the bonding properties of the material.According to the microstructure a series of diffusion layers were observed at the interface and the thicknesses of diffusion layers have increased with aging time as a result of the diffusion bonding.The interfaces were composed of 3-ply diffusion layers and their compositions were changed with aging time at 400 °C.These compositional compounds were revealed to be η2,(θ+η2),(α+θ) intermetallic phases.It is evident from V-notch impact tests that the growth of the brittle diffusion layers with the increasing aging time directly influenced delamination distance between the Cu sleeve and the Al core.It is suggested that the proper holding time at 400 °C for aging as post heat treatment of a drawn Cu/Al bar clad material would be within 1 h.展开更多
Cu/Al clad strips are prepared using solid?liquid cast-rolling bonding(SLCRB)technique with a d160mm×150mm twin-roll experimental caster.The extent of interfacial reactions,composition of the reaction products,an...Cu/Al clad strips are prepared using solid?liquid cast-rolling bonding(SLCRB)technique with a d160mm×150mm twin-roll experimental caster.The extent of interfacial reactions,composition of the reaction products,and their micro-morphology evolution in the SLCRB process are investigated with scanning electron microscope(SEM),energy dispersive spectrometer(EDS),and X-ray diffraction(XRD).In the casting pool,initial aluminized coating is first generated on the copper strip surface,with the diffusion layer mainly consisting ofα(Al)+CuAl2and growing at high temperatures,with the maximum thickness of10μm.After sequent rolling below the kiss point,the diffusion layer is broken by severe elongation,which leads to an additional crack bond process with a fresh interface of virgin base metal.The average thickness is reduced from10to5μm.The reaction products,CuAl2,CuAl,and Cu9Al4,are dispersed along the rolling direction.Peeling and bending test results indicate that the fracture occurs in the aluminum substrate,and the morphology is a dimple pattern.No crack or separation is found at the bonding interface after90°-180°bending.The presented method provides an economical way to fabricate Cu/Al clad strip directly.展开更多
Isothermal solidification process of a dissimilar transient liquid phase （TLP） bonding of FSX-414/MBF80/IN738 system was simulated by finite difference method. The TLP joint model was divided into two parts and a mo...Isothermal solidification process of a dissimilar transient liquid phase （TLP） bonding of FSX-414/MBF80/IN738 system was simulated by finite difference method. The TLP joint model was divided into two parts and a moving liquid /solid interface model was used for the parts. Diffusion equations were solved for each half of the joints simultaneously up to the end of isothermal solidification. The completion time of isothermal solidification, concentration profiles and position of the solid/liquid interface for each half were calculated. The intersection of the solid/liquid interfaces of two halves was considered the end of isothermal solidification. To obtain some required diffusion data, TLP bonding of FSX-414/MBF80/IN738 was performed at different temperature and time under vacuum atmosphere. The calculated results show good agreement with the experimental results.展开更多
For the immiscible Mo/Cu system with a positive heat of mixing （△Hm 〉 0）, building metallurgical bonding interfaces directly between immiscible Mo and Cu and preparing Mo/Cu laminar metal matrix composites （LMMCs...For the immiscible Mo/Cu system with a positive heat of mixing （△Hm 〉 0）, building metallurgical bonding interfaces directly between immiscible Mo and Cu and preparing Mo/Cu laminar metal matrix composites （LMMCs） are very difficult. To solve the problem, a new alloying method for immiscible systems, which is named as irradiation damage alloying （IDA）, is presented in this paper. The IDA primarily consists of three steps. Firstly, Mo is damaged by irradiation with multi-energy （186, 62 keV） Cu ion beams at a dose of 2× 1017 ions/cm2. Secondly, Cu layers are superimposed on the surfaces of the irradiation-damaged Mo to obtain Mo]Cu laminated specimens. Thirdly, the irradiation damage induces the diffusion alloying between Mo and Cu when the laminated specimens are annealed at 950 ℃ in a protective atmosphere. Through IDA, Mo/Cu LMMCs are prepared in this paper. The tensile tests carried out for the Mo/Cu LMMCs specimens show that the Mo/Cu interfaces constructed via IDA have high normal and shear strengths. Additionally, the microstructure of the Mo/Cu interface is characterized by High Resolution Transmission Electron Microscopy （HRTEM）, X-ray diffraction （XRD） and Energy Dispersive X-ray （EDX） attached in HRTEM. The microscopic characterization results show that the expectant diffusion between Mo and Cu occurs through the irradiation damage during the process of IDA. Thus a Mo/Cu metallurgical bonding interface successfully forms. Moreover, the microscopic test results show that the Mo/Cu metallurgical interface is mainly constituted of crystalline phases with twisted and tangled lattices, and amorphous phase is not observed. Finally, based on the positron annihilation spectroscopy （PAS） and HRTEM results, the diffusion mechanism of IDA is discussed and determined to be vacancy assisted diffusion.展开更多
Solid-state diffusion bonding(DB)of TiAl alloy and Ti2 AlNb alloy was carried out using pure Ti as an interlayer at 1000℃under 20 MPa for 60-120 min.The effects of bonding times on the interfacial microstructure and ...Solid-state diffusion bonding(DB)of TiAl alloy and Ti2 AlNb alloy was carried out using pure Ti as an interlayer at 1000℃under 20 MPa for 60-120 min.The effects of bonding times on the interfacial microstructure and mechanical performance of the TiAl/Ti/Ti_(2)AlNb bonded joints at room temperature(RT)were investigated detailly.The results demonstrated that the diffusion layers(DLs)mainly consisted of four characteristic layers,(Ⅰ)single coarseα_(2)phase adjacent TiAl alloy,(Ⅱ)single refinedα_(2)phase at the bonding interface,(Ⅲ)equiaxed/acicularα_(2)phase embedded inβphase adjacent Ti_(2)AtNb alloy and(IV)both equiaxedα_(2)phase and acicular O phase embedded inβphase adj acent Ti_(2)AlNb alloy,respectively.The thickness of the four layers increased with the increasing of the bonding time.The growth of DLs is controlled by diffusion and the reaction rate constant k for regionⅠ,Ⅱ,ⅢandⅣare 1.22×10^(-6),1.27×10^(-6),2.6×10^(-7)and 7.7×10^(-7)m·s^(-1/2),respectively.Meanwhile,the interfaceα_(2)grain grows up without texture.The maximum tensile strength of 281 MPa was maintained at1000℃for 90 min under the pressure of 20 MPa.Consequently,the phase transformation and dynamic recrystallization behavior of the DLs were discussed.展开更多
基金supported by the National Key R&D Program of China (No. 2018YFA0707300)the National Natural Science Foundation of China (No. 52374376)the Introduction Plan for High end Foreign Experts, China (No. G2023105001L)。
文摘Titanium plates with a Ti−O solid solution surface-hardened layer were cold roll-bonded with 304 stainless steel plates with high work hardening rates.The evolution and mechanisms affecting the interfacial bonding strength in titanium/stainless steel laminated composites were investigated.Results indicate that the hardened layer reduces the interfacial bonding strength from over 261 MPa to less than 204 MPa.During the cold roll-bonding process,the hardened layer fractures,leading to the formation of multi-scale cracks that are difficult for the stainless steel to fill.This not only hinders the development of an interlocking interface but also leads to the presence of numerous microcracks and hardened blocks along the nearly straight interface,consequently weakening the interfacial bonding strength.In metals with high work hardening rates,the conventional approach of enhancing interface interlocking and improving interfacial bonding strength by using a surface-hardened layer becomes less effective.
文摘In situ growth of co-catalysts on BiVO_(4)(BVO)to enhance photoelectrochemical(PEC)water splitting performance has been extensively reported.However,the understanding of the synergistic effects among various elements,especially at the interface between the semiconductor and cocatalyst,has received insufficient attention.In this study,we report a Co,Ni and Mn trimetallic fluoride-modified BVO photoanode featuring a unique interfacial chemical bond(V-F).Under AM 1.5 G illumination,an exciting photocurrent density of 6.05 mA cm^(-2)was achieved at 1.23 V vs.RHE by the integrated BVO/CoNi_(0.18)Mn_(0.12)(OH)_(x)F photoanode and over 98%of the initial photocurrent was maintained after 10 h of photoelectrolysis.Control experiments and theoretical calculations demonstrate that the V-F interfacial bond stabilizes the Co^(2+)active sites.It serves as a transmission gear,interlinking the migration of interfacial charge and the regeneration of cocatalyst,endowing the photoanode with significant activity and stability.Furthermore,we have systematically elucidated the role of the individual Co,Ni,and Mn components in the synergistic cocatalyst layer.The interfacial modification provides novel insights into developing advanced photoanodes towards PEC water splitting.
基金supported by National Key R&D Program of China(Grant No.2022YFB4600103)National Youth Talent Support Program,China Postdoctoral Science Foundation(Grant No.2021M692555)+1 种基金Shaanxi Province Qinchuangyuan'Scientists+Engineers'Team Building Project(Grant No.2023KXJ-266)Fundamental Research Funds for the Central Universities(Grant No.xzy012023145)。
文摘Multimaterial digital light processing(DLP)three-dimensional(3D)printing technology provides unique advantages in the field of multi material additive manufacturing(MM AM)with its high resolution and rapid shaping capabilities based on photopolymerization.However,owing to differences in the curing behavior and physical properties of different materials,multimaterial DLP 3D printing faces challenges such as insufficient interfacial bonding strength and unstable mechanical properties.In this study,two resins were integrated by multimaterial DLP 3D printing technology,and the effects of different layer thicknesses and exposure times on the interfacial bonding strength and morphology of the multimaterials were systematically investigated.The interfacial bonding mechanisms of the two resins was analyzed.It was found that increasing the exposure time can improve the interfacial bonding strength between materials,but certain limitations exist.A mathematical model relating the interfacial bonding strength to the exposure time and layer thickness was developed,and optimal process parameters were determined using optimization algorithms.A variable-parameter printing strategy for the interface was proposed to further improve the performance of printed parts.The maximum tensile strength of the multimaterial samples(44.43 MPa)using this strategy reached that of single-material parts(45 MPa),validating the feasibility of this strategy.This provides guidance for multimaterial DLP 3D printing processes and offers valuable insights for the future additive manufacturing of high-performance multimaterial components.
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supported by the National Natural Science Foundation of China(No.52474401)the Project funded by the China Postdoctoral Science Foundation(No.2022M712919)+1 种基金Open Project of State Key Laboratory of Advanced Brazing Filler Metals and Technology(SKLABFMT-2021-03)Guangdong Basic and Applied Basic Research Foundation(2023A1515140124).
文摘The unclear interfacial characteristics of Ag/Cu interface during diffusion welding limit the improvement of mechanical properties of Ag/Cu bimetallic strips.The growth orientation and evolution of Ag and Cu crystals between Ag and Cu strips were investigated by electron backscatter diffraction(EBSD)analysis,and the interfacial properties of various Ag/Cu interfacial configurations were calculated using first-principles calculations to elucidate the diversified interfacial characteristics.Three interface bonding states,including Ag(100)/Cu(100),Ag(110)/Cu(110)and Ag(111)/Cu(111),were preferentially formed in Ag/Cu bimetallic strips during roll bonding.The intensity of Ag(100)/Cu(100)interface increases with the increasing deformation amounts during cold rolling,accompanied by the decreased intensity of Ag(110)/Cu(110)and Ag(111)/Cu(111)interfaces.The largest adsorption work and lowest interface energy of Ag(100)/Cu(100)interface at the“center”position reveal the transition from Ag(110)/Cu(110)and Ag(111)/Cu(111)interfaces to Ag(100)/Cu(100)interface.
基金Project(51275416)supported by the National Natural Science Foundation of China
文摘The bonding interface characteristic and shear strength of diffusion bonded Ti-17 titanium alloy at different bonding time were investigated. The results show that the average size of voids decreases while the amount of voids decreases after increasing to the maximum value with the increasing bonding time. The irregular void with a scraggly edge tends to an ellipse void with smooth surface and then changes to a tiny void with round shape. The grains across bonding interface occur at bonding time of 60 min. The shear strength of bond increases with increasing bonding time, and the highest shear strength of bond is 887.4 MPa at 60 min. The contribution of plastic deformation on the void closure and the increase of shear strength is significant even though the action time of plastic deformation is short.
基金Project(BA2006067)supported by Achievement Transitional Foundation of Jiangsu Province,China
文摘A Fe/Al clad tube was prepared by explosive welding.Then the bonding characteristic of the interface was investigated by compression,flattening and compression-shear test.The test results exhibit that the clad tubes possessing good bonding interface have higher shear strength than that of pure aluminum and can bear both axial and radial deformation.The original interface between aluminum layer and ferrite layer was observed by scanning electron microscopy（SEM）.The results show that the clad tubes with good bonding properties possess the interface in wave and straight shape.The Fe/Al clad tube was used to manufacture the T-shape by hydro-bulging.It is found that the good-bonding interface of the Fe/Al clad tube plays a dominant role in the formation of the T-shape.
基金Project(2014M562447) supported by the China Postdoctoral Science FoundationProject(51275416) supported by the National Natural Science Foundation of China+1 种基金Project(BP201503) supported by the Research Fund of the State Key Laboratory of Solidification Processing(NWPU)China
文摘The effect of grain size of primary α phase on the bonding interface characteristic and shear strength of bond was investigated in the press bonding of Ti-6Al-4V alloy. The quantitative results show that the average size of voids increases from 0.8 to 2.6 μm and the bonding ratio decreases from 90.9% to 77.8% with an increase in grain size of primary α phase from 8.2 to 16.4 μm. The shape of voids changes from the tiny round to the irregular strip. The highest shear strength of bond can be obtained in the Ti-6Al-4V alloy with a grain size of 8.2 μm. This is contributed to the higher ability of plastic flow and more short-paths for diffusion in the alloy with smaller grain size of primary α phase, which promote the void closure process and the formation of α/β grains across bonding interface.
基金Project(2012CB723307)supported by the National Basic Research Program of ChinaProject(51204046)supported by the National Natural Science Foundation of ChinaProject(20130042130001)supported by the Doctoral Fund of Ministry of Education of China
文摘AA4045/AA3003 cladding billet was prepared by direct chill semi-continuous casting process. The macrostructures, microstructures, temperature distribution, compositions distribution and the mechanical properties at the bonding interface were investigated in detail. The results show that the cladding billet with few defects could be obtained by semi-continuous casting process. At the interface, diffusion layer of about 10μm on average formed between the two alloys due to the diffusion of alloy elements in the temperature range from 596 to 632 °C. From the side of AA4045 to the side of AA3003, the Si content has a trend to decrease, while the Mn content has a trend to increase gradually. Tensile strength of the cladding billet reaches 103.7 MPa, the fractured position is located on the AA3003 side, and the shearing strength is 91.1 MPa, revealing that the two alloys were combined metallurgically by mutual diffusion of alloy elements.
基金supported by the National Natural Science Foundation of China(Grant Nos.92164105 and 51975151)the Heilongjiang Provincial Natural Science Foundation of China under grant LH2019E041+1 种基金the Heilongjiang Touyan Innovation Team Program(HITTY-20190013)State Key Laboratory of Precision Welding&Joining of Materials and Structures(No.24-T-04)。
文摘Due to its superior nanoscale properties,cobalt(Co)is highly desirable for ultrahigh-density 3D integration into materials through metal/dielectric hybrid bonding.However,this process is very challenging through Co/SiO_(2)hybrid bonding,as very hydrophilic SiO_(2)surfaces are needed for bonding during dehydration reactions and oxidation of the Co surfaces must be avoided.Additionally,the substantial coefficient of thermal expansion mismatch between the robust capping layers(Co and SiO_(2)layers)necessitates hybrid bonding with minimal thermal input and compression.In this study,we introduce a ternary plasma activation strategy employing an Ar/NH_(3)/H_(2)O gas mixture to facilitate Co/SiO_(2)hybrid bonding at temperatures as low as~200℃,which is markedly lower than the melting point of Co(~1500℃).Intriguingly,non-oxide metallization at the Co-Co interface can be realized without the hindrance of a bonding barrier,thereby reducing the electrical resistance by over 40%and compression force requirements.Moreover,the enhancement in the SiO_(2)surface energy through active group terminations fosters extensive interfacial hydration and strengthens the mechanical properties.This research paves the way for fine-tuning bonding surfaces using a material-selective strategy which should advance metal/dielectric hybrid bonding for future integration applications.
基金Item Sponsored by National Natural Science Foundation of China(51474127)
文摘A hot compression bonding process was developed to prepare a novel laminated composite consisting of high-Cr cast iron （HCCI） as the inner layer and low carbon steel （LCS） as the outer layers on a Gleeble 3500 ther- momechanicat simulator at a temperature of 950 ℃ and a strain rate of 0. 001 s 1. Interfacial bond quality and hot deformation behaviour of the laminate were studied by mierostructural characterisation and mechanical tests. Experi- mental results show that the metallurgical bond between the constituent metals was achieved under the proposed bonding conditions without discernible defects and the formation of interlayer or intermetallic layer along the inter- face. The interfacial bond quality is excellent since no deterioration occurred around the interface which was deformed by Vickers indentation and compression test at room temperature with parallel loading to the interface. After well cladding by the LCS, the brittle HCCI can be severely deformed （about 57 % of reduction） at high temperature with crack-free. This significant improvement should be attributed to the decrease of crack sensitivity due to stress relief by soft claddings and enhanced flow property of the HCCI by simultaneous deformation with the LCS.
基金supported by the National Natural Science Foundation of China(Grant Nos.52369019,52004127)the Young Elite Scientists Sponsorship Program by JXAST(Grant No.2023QT06).
文摘The study of the shear behavior of bonded rock-cement interface is important for understanding the strength and stability of grouted rock masses.This research aims to reveal the failure mechanism behind the shear property of bonded rock-cement interfaces.For the study,sandstone and granite joint blocks with specific morphology were fabricated by using a three-dimensional(3D)engraving technique.Bonded rock-cement joints with asperity inclination angles of 15°,30°,and 45°were prepared.Shear tests were performed on these bonded rock-cement joints to investigate the shear response and failure modes considering the effect of applied normal stress and interface morphology.Meanwhile,the two-dimensional particle flow code(PFC2D)was utilized to model the entire shear process of bonded rock-cement interfaces.The macroscopic shear behavior and mesoscopic failure mechanism were comprehensively investigated by the laboratory test and numerical simulation.The results showed that the shear stress-displacement curves of bonded rock-cement joints exhibit two distinct peaks,and the shear stress evolution can be categorized into four stages including elastic growth,rapid stress drop,secondary stress growth,and progressive softening.Significantly,the number of acoustic emission events also exhibits two distinct peaks related to the double peak of the shear stress curves.The failure of bonded rock-cement interfaces is mainly induced by shear fractures,while the failure of rock and cement blocks is primarily caused by tensile fractures.The number of shear cracks in the bonded rock-cement interfaces reaches the peak when the shear stress reaches the primary peak;whereas as the shear stress continuously approaches the residual stage,the fracture of the bonded rock-cement joints is primarily characterized by tensile cracks in the blocks.
基金Financial supports for this work,provided by the National Natural Science Foundation Project of China(No.52374152)the Guangxi Science and Technology Plan Project of China(No.2022AB31023)the National Basic Research Development Program of China(No.2022YFC2904602)are gratefully acknowledged。
文摘The anchoring capacity of the anchor cable is closely related to the bonding length and radial pressure conditions.Through field pull-out tests,theoretical analysis,numerical simulation,and industrial tests,this study clarifies the relationship between radial pressure and bonding length for the ultimate pullout force and reveals the microscopic failure process of the resin-rock interface in the anchoring system.The results show that the ultimate load increases with the increase of bonding length in three different stages:rapid,slow,and uniform growth.The new mechanical model developed considering radial pressure describes the inverse relationship between radial pressure and the plastic zone on the bonding section,and quantifies the reinforcing effect of confining pressure on the anchoring force.During the pull-out process of the anchor cable,the generation of failure cracks is in the order of orifice,bottom,and middle of the hole.Radial pressure can effectively enhance the ultimate pull-out force,alleviate the oscillation increase of pull-out force,and inhibit resin cracking,but will produce an external crushing zone.It also reveals the synergistic effect between bonding length and radial pressure,and successfully carries out industrial tests of anchor cable support,which ensures the stability of the stope roof and provides an important reference for the design of anchor cable support in deep high-stress mines.
基金financially supported by the Major State Basic Research Development Program of China(No.2011CB012803)the National Natural Science Foundation of China (No. 51334006)
文摘The effect of temperature on interface microstructure and shear strength of 1420 A1-Li alloy and 7B04 A1 alloy composite plates prepared by diffusion bonding were investigated. The results indicate the optimum temperature for bonding the composite plates is 520℃, a sound bonding interface without continuous intermetallic compound layers and interfacial voids is obtained, and the shear strength value of bond joints can be as high as 190 MPa. An interfacial transition zone is formed due to the alloying elements mutual diffusion during the bonding process. Meanwhile, the effect of temperature on diffusion of alloying elements and interface reaction were discussed in detail, the results show that the higher temperature can increase the diffusion of alloying elements fluxes across the bonding interface, which can accelerate the closure of interfacial voids; meanwhile, when Mg atoms diffuse across the bonding interface, it can react with and break up the surface oxide films into discrete particles, and the removal of interface oxides increases the metal to metal bond areas and improves the bond quality.
文摘This article introduces an element diffusion behavior model for a titanium/steel explosive clad plate characterized by a typical curved interface during the heat-treatment process. A series of heat-treatment experiments were conducted in the temperature range from 750℃ to 950℃, and the effects of heat-treatment parameters on the microstructural evolution and diffusion behavior were investigated by optical microscopy, scanning electron microscopy, X-ray diffraction analysis, and electron-probe microanalysis. Carbon atoms within the steel matrix were observed to diffuse toward the titanium matrix and to aggregate at the bonding interface at 850℃ or lower; in contrast, when the temperature exceeded 850℃, the mutual diffusion of Ti and Fe occurred, along with the diffusion of C atoms, resulting in the for- marion of Ti-Fe intermetallics （Fe2Ti/FeTi）. The diffusion distances of C, Ti, and Fe atoms increased with increasing heating temperature and/or holding time. On the basis of this diffusion behavior, a novel diffusion model was proposed. This model considers the effects of various factors, including the curvature radius of the curved interface, the diffusion coefficient, the heating temperature, and the holding rime. The experimental results show good agreement with the calculated values. The proposed model could clearly provide a general prediction of the elements＇ diffusion at both straight and curved interfaces.
基金Project supported by the Fundamental Materials Development funded by the Korean Ministry of Knowledge Economy
文摘Cu/Al bar clad material was fabricated by a drawing process and a subsequent heat treatment.During these processes,intermetallic compounds have been formed at the interface of Cu/Al and have affected its bonding property.Microstructures of Cu/Al interfaces were observed by OM,SEM and EDX Analyser in order to investigate the bonding properties of the material.According to the microstructure a series of diffusion layers were observed at the interface and the thicknesses of diffusion layers have increased with aging time as a result of the diffusion bonding.The interfaces were composed of 3-ply diffusion layers and their compositions were changed with aging time at 400 °C.These compositional compounds were revealed to be η2,(θ+η2),(α+θ) intermetallic phases.It is evident from V-notch impact tests that the growth of the brittle diffusion layers with the increasing aging time directly influenced delamination distance between the Cu sleeve and the Al core.It is suggested that the proper holding time at 400 °C for aging as post heat treatment of a drawn Cu/Al bar clad material would be within 1 h.
基金Project(51474189)supported by the National Natural Science Foundation of ChinaProject(QN2015214)supported by the Educational Commission of Hebei Province,China
文摘Cu/Al clad strips are prepared using solid?liquid cast-rolling bonding(SLCRB)technique with a d160mm×150mm twin-roll experimental caster.The extent of interfacial reactions,composition of the reaction products,and their micro-morphology evolution in the SLCRB process are investigated with scanning electron microscope(SEM),energy dispersive spectrometer(EDS),and X-ray diffraction(XRD).In the casting pool,initial aluminized coating is first generated on the copper strip surface,with the diffusion layer mainly consisting ofα(Al)+CuAl2and growing at high temperatures,with the maximum thickness of10μm.After sequent rolling below the kiss point,the diffusion layer is broken by severe elongation,which leads to an additional crack bond process with a fresh interface of virgin base metal.The average thickness is reduced from10to5μm.The reaction products,CuAl2,CuAl,and Cu9Al4,are dispersed along the rolling direction.Peeling and bending test results indicate that the fracture occurs in the aluminum substrate,and the morphology is a dimple pattern.No crack or separation is found at the bonding interface after90°-180°bending.The presented method provides an economical way to fabricate Cu/Al clad strip directly.
文摘Isothermal solidification process of a dissimilar transient liquid phase （TLP） bonding of FSX-414/MBF80/IN738 system was simulated by finite difference method. The TLP joint model was divided into two parts and a moving liquid /solid interface model was used for the parts. Diffusion equations were solved for each half of the joints simultaneously up to the end of isothermal solidification. The completion time of isothermal solidification, concentration profiles and position of the solid/liquid interface for each half were calculated. The intersection of the solid/liquid interfaces of two halves was considered the end of isothermal solidification. To obtain some required diffusion data, TLP bonding of FSX-414/MBF80/IN738 was performed at different temperature and time under vacuum atmosphere. The calculated results show good agreement with the experimental results.
基金financially supported by the National Natural Science Foundation of China (Grant Nos. 51171128 and 51471114)the Key Technologies R & D Program of Tianjin (Grant No. 11ZCKFGX03800)
文摘For the immiscible Mo/Cu system with a positive heat of mixing （△Hm 〉 0）, building metallurgical bonding interfaces directly between immiscible Mo and Cu and preparing Mo/Cu laminar metal matrix composites （LMMCs） are very difficult. To solve the problem, a new alloying method for immiscible systems, which is named as irradiation damage alloying （IDA）, is presented in this paper. The IDA primarily consists of three steps. Firstly, Mo is damaged by irradiation with multi-energy （186, 62 keV） Cu ion beams at a dose of 2× 1017 ions/cm2. Secondly, Cu layers are superimposed on the surfaces of the irradiation-damaged Mo to obtain Mo]Cu laminated specimens. Thirdly, the irradiation damage induces the diffusion alloying between Mo and Cu when the laminated specimens are annealed at 950 ℃ in a protective atmosphere. Through IDA, Mo/Cu LMMCs are prepared in this paper. The tensile tests carried out for the Mo/Cu LMMCs specimens show that the Mo/Cu interfaces constructed via IDA have high normal and shear strengths. Additionally, the microstructure of the Mo/Cu interface is characterized by High Resolution Transmission Electron Microscopy （HRTEM）, X-ray diffraction （XRD） and Energy Dispersive X-ray （EDX） attached in HRTEM. The microscopic characterization results show that the expectant diffusion between Mo and Cu occurs through the irradiation damage during the process of IDA. Thus a Mo/Cu metallurgical bonding interface successfully forms. Moreover, the microscopic test results show that the Mo/Cu metallurgical interface is mainly constituted of crystalline phases with twisted and tangled lattices, and amorphous phase is not observed. Finally, based on the positron annihilation spectroscopy （PAS） and HRTEM results, the diffusion mechanism of IDA is discussed and determined to be vacancy assisted diffusion.
基金the National Natural Science Foundation of China(No.51771150)the National Key Research and Development Program of China(No.2016YFB0701303)+1 种基金the Aeronautical Science Foundation of China(No.201936053001)the Research Fund of the State Key Laboratory of Solidification(NWPU),China(No.2019-TS-07)。
文摘Solid-state diffusion bonding(DB)of TiAl alloy and Ti2 AlNb alloy was carried out using pure Ti as an interlayer at 1000℃under 20 MPa for 60-120 min.The effects of bonding times on the interfacial microstructure and mechanical performance of the TiAl/Ti/Ti_(2)AlNb bonded joints at room temperature(RT)were investigated detailly.The results demonstrated that the diffusion layers(DLs)mainly consisted of four characteristic layers,(Ⅰ)single coarseα_(2)phase adjacent TiAl alloy,(Ⅱ)single refinedα_(2)phase at the bonding interface,(Ⅲ)equiaxed/acicularα_(2)phase embedded inβphase adjacent Ti_(2)AtNb alloy and(IV)both equiaxedα_(2)phase and acicular O phase embedded inβphase adj acent Ti_(2)AlNb alloy,respectively.The thickness of the four layers increased with the increasing of the bonding time.The growth of DLs is controlled by diffusion and the reaction rate constant k for regionⅠ,Ⅱ,ⅢandⅣare 1.22×10^(-6),1.27×10^(-6),2.6×10^(-7)and 7.7×10^(-7)m·s^(-1/2),respectively.Meanwhile,the interfaceα_(2)grain grows up without texture.The maximum tensile strength of 281 MPa was maintained at1000℃for 90 min under the pressure of 20 MPa.Consequently,the phase transformation and dynamic recrystallization behavior of the DLs were discussed.
