Copper and niobium connector and connecting method thereof

Abstract

The invention relates to the technical field of copper niobium superconducting cavity making, in particular to a copper and niobium connector and a connecting method thereof. The copper and niobium connector is characterized in that the connector is composed of a copper plate, a silver intermediate layer and a niobium plate, and the upper and lower ends of the silver intermediate layer are connected with the copper plate and the niobium plate correspondingly. The connecting method includes the following steps that firstly, the to-be-connected surfaces of the niobium plate and the copper plateare ground to obtain the fresh metal surfaces, and acetone or ethyl alcohol are used for ultrasonic cleaning; secondly, metallic silver which can react eutectically with copper and form a solid solution with niobium is selected as the intermediate layer; and thirdly, the niobium plate, the silver intermediate layer and the copper plate are assembled together and put into a heating furnace, the mixture is pressurized, vacuumized and then heated for connection, and niobium silver copper connector is obtained after cooling and removing. The copper and niobium connector and the connecting method thereof have the advantages that the method is simple, the silver is used as the intermediate layer to connect the copper and the niobium, connection at the low temperature is realized, and good strength and deformation ability of a joint are ensured.

Description

technical field [0001] The invention relates to the technical field of manufacturing copper-niobium superconducting cavities, in particular to a copper-niobium connection using silver as an intermediate layer to realize connection at a relatively low temperature and ensure that the joint has good strength and deformability. Niobium connectors and connection methods. Background technique [0002] As we all know, metal niobium has excellent low-temperature superconductivity and is the key component material in superconducting acceleration chambers. However, niobium is expensive and has a low thermal conductivity of only 53.7 W / (m·K). The working state of the cavity needs to be combined with copper (386 W / (m K)) with high thermal conductivity, and the copper-niobium cavity has attracted more and more attention. [0003] At present, the existing literature "Development and preliminary experiments of copper-niobium sputtering low-β superconducting cavity, Hao Jiankui, Zhao Kui, ...

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Problems solved by technology

[0003] At present, the existing literature "Development and preliminary experiments of copper-niobium sputtering low-β superconducting cavity, Hao Jiankui, Zhao Kui, Zhang Baocheng, Xie Dalin, Wang Lifang, Quan Shengwen, Shen Zilin, Tang Yuxing, Zhang Yunchi, Yang Xi, Hu Yanle, Zhao Kun. High Energy Physics and Nuclear Physics 2001, 25(6): 582-587” discloses a method of sputtering a layer of niobium film on the surface of a copper cavity. This method is difficult to obtain a dense and uniform niobium film. On the one hand, it is very difficult to ensure good adhesion between the two, because the copper / niobium system has a positive enthalpy of formation, and there are large differences between density, melting point and crystal structure. In the equilibrium phase diagram, whether it is liquid or solid phase, and their mutual solubility is limited. In short, the existing methods are difficult to ensure the connection strength between copper and niobium and the good performance of the copper-niobium cavity.

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