The interfacial structure and its effect on the resistivity of cross-layered silver-copper composite strip fabricated by hot-roll bonding and diffusion welding processes with the same specification were studied.Throug...The interfacial structure and its effect on the resistivity of cross-layered silver-copper composite strip fabricated by hot-roll bonding and diffusion welding processes with the same specification were studied.Through optical and scanning electron microscope analysis of metallographic structure of the diffusion region of interface,it is found that the thickness of the interfacial diffusion layer is related to the composite conditions.Under the condition of sufficient diffusion,the interface of silver-copper composite strip produced by diffusion welding process has a wider interfacial transition region and fine grain area.Due to the higher diffusion rate of copper atoms than that of silver atoms,copper atoms tend to aggregate at the silver boundaries to form a copper-rich second solid solution,which has a fixing and expanding effect during annealing.The fine grain area at the interface of the composite strip produced by diffusion welding process still exists after annealing treatment and reaches a width of 55-97μm.While the fine grain region at the interface of hot-rolled composite strips is mainly formed by crushing the surface under rolling pressure with less diffusion effect,it almost disappears after annealing.The resistivity of silver-copper composite strip increases with the extension of the interfacial diffusion region.The resistivity of hot-roll bonding composite strip is increased by about 4%higher than that of the theoretical calculation,while the resistivity of diffusion welding composite strip is increased by 6%.展开更多
1 Results The discovery of thefamily of mercury cupratesinthe eighties ,which present the highest Curie Temper-ature (Tc) among all known High Temperature Super-Conductors (HTSC) 。
基金supported by the National Key Research and Development Program of China(Grant No.2017YFB0305701)Henan Provincial Science and Technology Research Project(Grant No.182102210138)Science and Technology Openness and Cooperation Projects of Henan Province(Grant No.162106000002).
文摘The interfacial structure and its effect on the resistivity of cross-layered silver-copper composite strip fabricated by hot-roll bonding and diffusion welding processes with the same specification were studied.Through optical and scanning electron microscope analysis of metallographic structure of the diffusion region of interface,it is found that the thickness of the interfacial diffusion layer is related to the composite conditions.Under the condition of sufficient diffusion,the interface of silver-copper composite strip produced by diffusion welding process has a wider interfacial transition region and fine grain area.Due to the higher diffusion rate of copper atoms than that of silver atoms,copper atoms tend to aggregate at the silver boundaries to form a copper-rich second solid solution,which has a fixing and expanding effect during annealing.The fine grain area at the interface of the composite strip produced by diffusion welding process still exists after annealing treatment and reaches a width of 55-97μm.While the fine grain region at the interface of hot-rolled composite strips is mainly formed by crushing the surface under rolling pressure with less diffusion effect,it almost disappears after annealing.The resistivity of silver-copper composite strip increases with the extension of the interfacial diffusion region.The resistivity of hot-roll bonding composite strip is increased by about 4%higher than that of the theoretical calculation,while the resistivity of diffusion welding composite strip is increased by 6%.
文摘1 Results The discovery of thefamily of mercury cupratesinthe eighties ,which present the highest Curie Temper-ature (Tc) among all known High Temperature Super-Conductors (HTSC) 。
