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
Preferential oxidation of CO(CO-PROX)in H_(2)-rich streams is highly important for purifying the industrial grade H_(2)used in proton-exchange-membrane fuel cells(PEMFC),but it is still limited to a relatively narrow ...Preferential oxidation of CO(CO-PROX)in H_(2)-rich streams is highly important for purifying the industrial grade H_(2)used in proton-exchange-membrane fuel cells(PEMFC),but it is still limited to a relatively narrow operation temperature window.In this study,the trace amounts of Cu are used to modify a Pt/Al_(2)O_(3)catalyst.The introduced Cu_(2+)species are atomically anchored on Pt nanoparticles through strong electrostatic adsorption.展开更多
Cu2ZnSnS（e）4 （CZTS（e）） solar cells have attracted much attention due to the elemental abundance and the non- toxicity. However, the record efficiency of 12.6% for CuzZnSn（S,Se）4 （CZTSSe） solar cells is much ...Cu2ZnSnS（e）4 （CZTS（e）） solar cells have attracted much attention due to the elemental abundance and the non- toxicity. However, the record efficiency of 12.6% for CuzZnSn（S,Se）4 （CZTSSe） solar cells is much lower than that of Cu（In,Ga）See （CIGS） solar cells. One crucial reason is the recombination at interfaces. In recent years, large amount inves- tigations have been done to analyze the interfacial problems and improve the interfacial properties via a variety of methods. This paper gives a review of progresses on interfaces of CZTS（e） solar cells, including： （i） the band alignment optimization at buffer/CZTS（e） interface, （ii） tailoring the thickness of MoS（e）2 interfacial layers between CZTS（e） absorber and Mo back contact, （iii） the passivation of rear interface, （iv） the passivation of front interface, and （v） the etching of secondary phases.展开更多
The growth of Au-Sn intermetallic compounds(IMCs) is a major concern to the reliability of solder joints in microelectronic,optoelectronic and micro-electronic-mechanical system(MEMS) which has a layer of Au metalliza...The growth of Au-Sn intermetallic compounds(IMCs) is a major concern to the reliability of solder joints in microelectronic,optoelectronic and micro-electronic-mechanical system(MEMS) which has a layer of Au metallization on the surface of components or leads.This paper presented the growth behavior of Au-Sn IMCs at interfaces of Au metallization and Sn-based solder joints with the addition of Cu alloying element during aging process,and growth coefficients of the Au-Sn IMCs were calculated.Results on the interfacial reaction between Sn-xCu solders and Au metallization during aging process show that three layers of Au-Sn IMCs including AuSn,AuSn2 and AuSn4 formed at the interface region.The thickness of each Au-Sn IMC layer vs square root of aging time follows linear relationship.Calculation of the IMC growth coefficients shows that the diffusion coefficients decrease with the addition Cu elements,which indicates that Cu addition suppresses the growth of Au-Sn IMCs layer.展开更多
A nickel-based coating was deposited on the pure Al substrate by immersion plating,and the Al/Cu bimetals were prepared by diffusion bonding in the temperature range of 450-550 ℃.The interce microstructure and fractu...A nickel-based coating was deposited on the pure Al substrate by immersion plating,and the Al/Cu bimetals were prepared by diffusion bonding in the temperature range of 450-550 ℃.The interce microstructure and fracture surface of Al/Cu joints were studied by scanning electron microscopy（SEM） and X-ray diffraction（XRD）.The mechanical properties of the Al/Cu bimetals were measured by tensile shear and microhardness tests.The results show that the Ni interiayer can effectively eliminate the formation of Al-Cu intermetallic compounds.The Al/Ni interface consists of the Al3Ni and Al3Ni2 phases,while it is Ni-Cu solid solution at the Ni/Cu interce.The tensile shear strength of the joints is improved by the addition of Ni interiayer.The joint with Ni interiayer annealed at 500 ℃ exhibits a maximum value of tensile shear strength of 34.7 MPa.展开更多
The matrix accumulative roll bonding technology （MARB） can improve the matrix performance of metal composite and strengthen the bonding quality of the interface./n this research, for the fwst time, the technology of...The matrix accumulative roll bonding technology （MARB） can improve the matrix performance of metal composite and strengthen the bonding quality of the interface./n this research, for the fwst time, the technology of MARB was proposed. A sound Cu/AI bonding composite was obtained using the MARB process and the bonding characteristic of the interface was studied using scanning electricity microscope （SEM） and energy-dispersive spectroscopy （EDS）. The result indicated that accumulation cycles and diffusion annealing temperature were the most important factors for fabricating a Cu/AI composite material. The substrate aluminum was strengthened by MARB, and a high quality Cu/AI composite with sound interface was obtained as well.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
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financially supported by the National Key Research and Development Program of China(No.2022YFB3504200)the National Natural Science Foundation of China(Nos.U21A20326 and 22376063)+4 种基金the fund of the National Engineering Laboratory for Mobile Source Emission Control Technology(No.NELMS2020A05)the Fundamental Research Funds for the Central Universitiesthe funding received from the European Union's Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement No 897197.Y.L.(CSC No.202006740085)is grateful for thegrant from the China Scholarship Councilthe ICREA Academia program and grants MICINN/FEDER PID2021124572OB-C31 and GC 2021 SGR 01061part of Maria de Maeztu Units of Excellence Programme CEX2023-001300-M/funded by MCIN/AEI/https://doi.org/10.13039/501100011033
文摘Preferential oxidation of CO(CO-PROX)in H_(2)-rich streams is highly important for purifying the industrial grade H_(2)used in proton-exchange-membrane fuel cells(PEMFC),but it is still limited to a relatively narrow operation temperature window.In this study,the trace amounts of Cu are used to modify a Pt/Al_(2)O_(3)catalyst.The introduced Cu_(2+)species are atomically anchored on Pt nanoparticles through strong electrostatic adsorption.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51572132,51372121,and 61674082)the Natural Science Foundation of Key Project of Tianjin City,China(Grant No.16JCZDJC30700)+1 种基金the Yang Fan Innovative and Entrepreneurial Research Team Project of China(Grant No.2014YT02N037)111 Project,China(Grant No.B16027)
文摘Cu2ZnSnS（e）4 （CZTS（e）） solar cells have attracted much attention due to the elemental abundance and the non- toxicity. However, the record efficiency of 12.6% for CuzZnSn（S,Se）4 （CZTSSe） solar cells is much lower than that of Cu（In,Ga）See （CIGS） solar cells. One crucial reason is the recombination at interfaces. In recent years, large amount inves- tigations have been done to analyze the interfacial problems and improve the interfacial properties via a variety of methods. This paper gives a review of progresses on interfaces of CZTS（e） solar cells, including： （i） the band alignment optimization at buffer/CZTS（e） interface, （ii） tailoring the thickness of MoS（e）2 interfacial layers between CZTS（e） absorber and Mo back contact, （iii） the passivation of rear interface, （iv） the passivation of front interface, and （v） the etching of secondary phases.
基金This work was financially supported by the National Natural Science Foundation of China ( No 50675047/ E052105)Joint Project between Samsung Electronics Co Ltd( Korea) and Harbin Institute of Technology( HIT)
文摘The growth of Au-Sn intermetallic compounds(IMCs) is a major concern to the reliability of solder joints in microelectronic,optoelectronic and micro-electronic-mechanical system(MEMS) which has a layer of Au metallization on the surface of components or leads.This paper presented the growth behavior of Au-Sn IMCs at interfaces of Au metallization and Sn-based solder joints with the addition of Cu alloying element during aging process,and growth coefficients of the Au-Sn IMCs were calculated.Results on the interfacial reaction between Sn-xCu solders and Au metallization during aging process show that three layers of Au-Sn IMCs including AuSn,AuSn2 and AuSn4 formed at the interface region.The thickness of each Au-Sn IMC layer vs square root of aging time follows linear relationship.Calculation of the IMC growth coefficients shows that the diffusion coefficients decrease with the addition Cu elements,which indicates that Cu addition suppresses the growth of Au-Sn IMCs layer.
基金Projects (51274054,51375070,51271042) supported by the National Natural Science Foundation of ChinaProjects (2013M530913) supported by the China Postdoctoral Science Foundation
文摘A nickel-based coating was deposited on the pure Al substrate by immersion plating,and the Al/Cu bimetals were prepared by diffusion bonding in the temperature range of 450-550 ℃.The interce microstructure and fracture surface of Al/Cu joints were studied by scanning electron microscopy（SEM） and X-ray diffraction（XRD）.The mechanical properties of the Al/Cu bimetals were measured by tensile shear and microhardness tests.The results show that the Ni interiayer can effectively eliminate the formation of Al-Cu intermetallic compounds.The Al/Ni interface consists of the Al3Ni and Al3Ni2 phases,while it is Ni-Cu solid solution at the Ni/Cu interce.The tensile shear strength of the joints is improved by the addition of Ni interiayer.The joint with Ni interiayer annealed at 500 ℃ exhibits a maximum value of tensile shear strength of 34.7 MPa.
基金the National Natural Science Foundation of China (No. 50375019).
文摘The matrix accumulative roll bonding technology （MARB） can improve the matrix performance of metal composite and strengthen the bonding quality of the interface./n this research, for the fwst time, the technology of MARB was proposed. A sound Cu/AI bonding composite was obtained using the MARB process and the bonding characteristic of the interface was studied using scanning electricity microscope （SEM） and energy-dispersive spectroscopy （EDS）. The result indicated that accumulation cycles and diffusion annealing temperature were the most important factors for fabricating a Cu/AI composite material. The substrate aluminum was strengthened by MARB, and a high quality Cu/AI composite with sound interface was obtained as well.
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.
