The super-aligned carbon nanotube(SACNT)films reinforced copper(Cu)laminar composites with different orientationsof CNT ply were fabricated by electrodeposition.The results show that the tensile strength and yield str...The super-aligned carbon nanotube(SACNT)films reinforced copper(Cu)laminar composites with different orientationsof CNT ply were fabricated by electrodeposition.The results show that the tensile strength and yield strength of cross-ply compositewith5.0%(volume fraction)of SACNT reach maximum of336.3MPa and246.0MPa respectively,increased by74.0%and124.5%compared with pure Cu prepared with the same method.Moreover,the electrical conductivities of all the prepared composites areover75%IACS.The result of TEM analysis shows that the size of Cu grain and the thickness of twin lamellae can be reduced byadding SACNT,and the refining effect in cross-ply composites is more significant than that in unidirectional ply composites.Theenhanced strength of the Cu/SACNT composites comes from not only the reinforcing effect of SACNT films but also the additionalstrengthening of the Cu grain refinement caused by CNT orientation.展开更多
Cu/Al laminar composite was prepared by dipping Zn layer and then electroplating Cu thick layer on pure Al sheet.During annealing the Cu/Al composites at temperature from 473 to 673 K, the Cu/Al interfacial diffusion ...Cu/Al laminar composite was prepared by dipping Zn layer and then electroplating Cu thick layer on pure Al sheet.During annealing the Cu/Al composites at temperature from 473 to 673 K, the Cu/Al interfacial diffusion and reaction and itskinetics and also the electrical resistivity of the composites were studied. The results show that no Cu?Al IMC layer is observable asthe composites are annealed at 473 K for time till 360 h, indicating that the Zn intermediate layer can effectively suppress the Cu/Alinterfacial diffusion. However, as the composites are annealed at 573 K and above, Zn atoms in the Zn layer dissolve into the Culayer. Tri-layered reaction product of CuAl2/CuAl/Cu9Al4 then forms from the Al side to the Cu side. The IMC layer follows thediffusion-controlled growth kinetics. Electrical resistivity of the Cu/Al composites increases with the increase of the annealingtemperature and time.展开更多
Developing laminar composite solid electrolyte with ultrathin thickness and continuous conduction channels in vertical direction holds great promise for all-solid-state lithium batteries.Herein,a thin,laminar solid el...Developing laminar composite solid electrolyte with ultrathin thickness and continuous conduction channels in vertical direction holds great promise for all-solid-state lithium batteries.Herein,a thin,laminar solid electrolyte is synthesized by filtrating–NH 2 functionalized metal-organic framework nanosheets and then being threaded with poly(ethylene oxide)chains induced by the hydrogen-bonding interaction from–NH_(2) groups.It is demonstrated that the threaded poly(ethylene oxide)chains lock the adjacent metal-organic framework nanosheets,giving highly enhanced structural stability(Young’s modulus,1.3 GPa)to 7.5-μm-thick laminar composite solid electrolyte.Importantly,these poly(ethylene oxide)chains with stretching structure serve as continuous conduction pathways along the chains in pores.It makes the non-conduction laminar metal-organic framework electrolyte highly conductive:3.97×10^(−5) S cm^(−1) at 25℃,which is even over 25 times higher than that of pure poly(ethylene oxide)electrolyte.The assembled lithium cell,thus,acquires superior cycling stability,initial discharge capacity(148 mAh g^(−1) at 0.5 C and 60℃),and retention(94% after 150 cycles).Besides,the pore size of nanosheet is tailored(24.5–40.9˚A)to evaluate the mechanisms of chain conformation and ion transport in confined space.It shows that the confined pore only with proper size could facilitate the stretching of poly(ethylene oxide)chains,and meanwhile inhibit their disorder degree.Specifically,the pore size of 33.8˚A shows optimized confinement effect with trans-poly(ethylene oxide)and cis-poly(ethylene oxide)conformation,which offers great significance in ion conduction.Our design of poly(ethylene oxide)-threaded architecture provides a platform and paves a way to the rational design of next-generation high-performance porous electrolytes.展开更多
A new kind of laminar metal matrix nanocomposite（MMC） was fabricated by an electrodeposition process with copper and superaligned carbon nanotubes film（SACNT film）.The SACNT film was put on a titanium plate and th...A new kind of laminar metal matrix nanocomposite（MMC） was fabricated by an electrodeposition process with copper and superaligned carbon nanotubes film（SACNT film）.The SACNT film was put on a titanium plate and then a layer of copper was electrodeposited on it.By repeating the above process,the laminar Cu/SACNT composite which contains dozens or hundreds of layers of copper and SACNT films was obtained.The thickness of a single copper layer was controlled by adjusting the process parameter easily and the thinnest layer is less than 2 μm.The microscopic observation shows that the directional alignment structure of SACNT is retained in the composite perfectly.The mechanical and electrical properties testing results show that the tensile and yield strengths of composites are improved obviously compared with those of pure copper,and the high conductivity is retained.This technology is a potential method to make applicable MMC which characterizes high volume fraction and directional alignment of carbon nanotubes.展开更多
Recently, quasimolecular dynamics has been successfully used to simulate the deformation characteristics of actual size solid materials. In quasimolecular dynamics, which is an attempt to bridge the gap between atomis...Recently, quasimolecular dynamics has been successfully used to simulate the deformation characteristics of actual size solid materials. In quasimolecular dynamics, which is an attempt to bridge the gap between atomistic and continuum simulations, molecules are aggregated into large units, called quasimolecules, to evaluate large scale material behavior. In this paper, a 2-dimensional numerical simulation using quasimolecular dynamics was performed to investigate laminar composite material fractures and crack propagation behavior in the uniform bending of laminar composite materials. It was verified that under bending deformation laminar composite materials deform quite differently from homogeneous materials展开更多
A survey about OJSC "SIC Supermetal'" as a processor of secondary precious metal raw materials and a manufacturer of precious metal products for technical purposes,has been presented.Brief information ha...A survey about OJSC "SIC Supermetal'" as a processor of secondary precious metal raw materials and a manufacturer of precious metal products for technical purposes,has been presented.Brief information has been given about the basic technologies and materials used in production,including dispersion strengthened materials on the basis of platinum alloys and laminar composites.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
基金Project(20111080980) supported by the Initiative Scientific Research Program,Tsinghua University,ChinaProject(2013AA031201) supported by the High Technology Research and Development Program of China
文摘The super-aligned carbon nanotube(SACNT)films reinforced copper(Cu)laminar composites with different orientationsof CNT ply were fabricated by electrodeposition.The results show that the tensile strength and yield strength of cross-ply compositewith5.0%(volume fraction)of SACNT reach maximum of336.3MPa and246.0MPa respectively,increased by74.0%and124.5%compared with pure Cu prepared with the same method.Moreover,the electrical conductivities of all the prepared composites areover75%IACS.The result of TEM analysis shows that the size of Cu grain and the thickness of twin lamellae can be reduced byadding SACNT,and the refining effect in cross-ply composites is more significant than that in unidirectional ply composites.Theenhanced strength of the Cu/SACNT composites comes from not only the reinforcing effect of SACNT films but also the additionalstrengthening of the Cu grain refinement caused by CNT orientation.
基金Project(2012QTXM0751)supported by the Scientific and Technological Research Project,State Grid,China
文摘Cu/Al laminar composite was prepared by dipping Zn layer and then electroplating Cu thick layer on pure Al sheet.During annealing the Cu/Al composites at temperature from 473 to 673 K, the Cu/Al interfacial diffusion and reaction and itskinetics and also the electrical resistivity of the composites were studied. The results show that no Cu?Al IMC layer is observable asthe composites are annealed at 473 K for time till 360 h, indicating that the Zn intermediate layer can effectively suppress the Cu/Alinterfacial diffusion. However, as the composites are annealed at 573 K and above, Zn atoms in the Zn layer dissolve into the Culayer. Tri-layered reaction product of CuAl2/CuAl/Cu9Al4 then forms from the Al side to the Cu side. The IMC layer follows thediffusion-controlled growth kinetics. Electrical resistivity of the Cu/Al composites increases with the increase of the annealingtemperature and time.
基金The authors would like to acknowledge the financial support from National Nat-ural Science Foundation of China (U2004199)Excellent Youth Foundation of Henan Province (202300410373)+2 种基金China Postdoctoral Science Foundation (2021T140615 and 2020M672281)Natural Science Foundation of Henan Province (212300410285)Young Talent Support Project of Henan Province(2021HYTP028).
文摘Developing laminar composite solid electrolyte with ultrathin thickness and continuous conduction channels in vertical direction holds great promise for all-solid-state lithium batteries.Herein,a thin,laminar solid electrolyte is synthesized by filtrating–NH 2 functionalized metal-organic framework nanosheets and then being threaded with poly(ethylene oxide)chains induced by the hydrogen-bonding interaction from–NH_(2) groups.It is demonstrated that the threaded poly(ethylene oxide)chains lock the adjacent metal-organic framework nanosheets,giving highly enhanced structural stability(Young’s modulus,1.3 GPa)to 7.5-μm-thick laminar composite solid electrolyte.Importantly,these poly(ethylene oxide)chains with stretching structure serve as continuous conduction pathways along the chains in pores.It makes the non-conduction laminar metal-organic framework electrolyte highly conductive:3.97×10^(−5) S cm^(−1) at 25℃,which is even over 25 times higher than that of pure poly(ethylene oxide)electrolyte.The assembled lithium cell,thus,acquires superior cycling stability,initial discharge capacity(148 mAh g^(−1) at 0.5 C and 60℃),and retention(94% after 150 cycles).Besides,the pore size of nanosheet is tailored(24.5–40.9˚A)to evaluate the mechanisms of chain conformation and ion transport in confined space.It shows that the confined pore only with proper size could facilitate the stretching of poly(ethylene oxide)chains,and meanwhile inhibit their disorder degree.Specifically,the pore size of 33.8˚A shows optimized confinement effect with trans-poly(ethylene oxide)and cis-poly(ethylene oxide)conformation,which offers great significance in ion conduction.Our design of poly(ethylene oxide)-threaded architecture provides a platform and paves a way to the rational design of next-generation high-performance porous electrolytes.
基金Project(20111080980)supported by the Initiative Scientific Research Program,Tsinghua University,China
文摘A new kind of laminar metal matrix nanocomposite（MMC） was fabricated by an electrodeposition process with copper and superaligned carbon nanotubes film（SACNT film）.The SACNT film was put on a titanium plate and then a layer of copper was electrodeposited on it.By repeating the above process,the laminar Cu/SACNT composite which contains dozens or hundreds of layers of copper and SACNT films was obtained.The thickness of a single copper layer was controlled by adjusting the process parameter easily and the thinnest layer is less than 2 μm.The microscopic observation shows that the directional alignment structure of SACNT is retained in the composite perfectly.The mechanical and electrical properties testing results show that the tensile and yield strengths of composites are improved obviously compared with those of pure copper,and the high conductivity is retained.This technology is a potential method to make applicable MMC which characterizes high volume fraction and directional alignment of carbon nanotubes.
文摘Recently, quasimolecular dynamics has been successfully used to simulate the deformation characteristics of actual size solid materials. In quasimolecular dynamics, which is an attempt to bridge the gap between atomistic and continuum simulations, molecules are aggregated into large units, called quasimolecules, to evaluate large scale material behavior. In this paper, a 2-dimensional numerical simulation using quasimolecular dynamics was performed to investigate laminar composite material fractures and crack propagation behavior in the uniform bending of laminar composite materials. It was verified that under bending deformation laminar composite materials deform quite differently from homogeneous materials
文摘A survey about OJSC "SIC Supermetal'" as a processor of secondary precious metal raw materials and a manufacturer of precious metal products for technical purposes,has been presented.Brief information has been given about the basic technologies and materials used in production,including dispersion strengthened materials on the basis of platinum alloys and laminar composites.
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.
