Preparation method of high-performance textured copper-nickel alloy composite base band for coated conductor

Abstract

The invention discloses a preparation method of a high-performance textured copper-nickel alloy composite base band for a coated conductor. The initial material of a surface layer is copper-nickel mixed powder (with code name of A) with the weight percentage content of nickel of 60%, and the initial material of a core layer is nickel-tungsten mixed powder (with code number of B) with the weight percentage content of tungsten of 9-10%. A preparation process comprises the following steps: filling the mixed powder A and B to a die layer by layer according to a sequence of A-B-A, carrying out cold isostatic pressing to prepare a three-layer initial composite blank with an outer layer being A and a core layer being B, firstly carrying out cold isostatic pressing on the initial composite blank, then carrying out compacting sintering by adopting cold isostatic pressing to obtain a layered copper-nickel alloy composite billet, and then carrying out large-deformation cold rolling on the layered copper-nickel alloy composite billet, wherein the pass deformation of the first five passes is 20-25%, the deformation of each subsequence pass is 3-10%, and the total deformation is 90%, and finally carrying out recrystallizing heat treatment with heat preservation of 50-90min at 900 DEG C, so as to obtain the non-magnetic copper-nickel alloy composite base band with high strength and strong cubic structure.

Description

technical field [0001] The invention belongs to the technical field of textured metal substrates for reinforced high-temperature coating superconductors, and in particular relates to a preparation method for high-performance textured copper-nickel alloy composite substrates for coated conductors. Background technique [0002] Since the discovery of the second-generation high-temperature superconducting materials represented by YBCO, it has attracted extensive attention from various research institutions around the world. In 1996, the Oak Ridge National Laboratory of the United States obtained a strong cubic texture after undergoing large-scale cold rolling of pure nickel and proper recrystallization heat treatment, which can be used as a tough metal texture substrate for high-temperature coated superconductor YBCO , this technique is called calender-assisted biaxially textured baseband technique. At present, the preparation process of Ni5W alloy baseband is very mature, but...

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Problems solved by technology

At present, the preparation process of Ni5W alloy baseband is very mature, but because of its ferromagnetism in the liquid nitrogen temperature zone, it will cause hysteresis loss in the application of alternating current. When the atomic percentage of W reaches more than 9%, nickel-tungsten The alloy baseband exhibits no ferromagnetism in the liquid nitrogen temperature zone, but at this time it is difficult to form a strong cubic texture on the surface of the nickel-tungsten alloy baseband through the traditional baseband preparation technology

The study found that when the copper content is above 54at.%, the copper-nickel alloy base strip is non-magnetic in the liquid nitrogen temperature range, but the yield strength of the copper-nickel alloy base strip is low, which is still not an ideal texture for coated conductors Metal baseband, in order to increase the mechanical strength of copper-nickel alloy baseband, the patent with publication number CN101786352A discloses a preparation method of a non-magnetic cubic textured copper-based alloy composite baseband, using cold isostatic pressing and discharge plasma sintering to make billets A non-magnetic composite baseband with non-magnetic copper-nickel alloy as the outer layer and high-strength nickel-tungsten alloy as the core layer was prepared. Compared with the corresponding single-layer copper-nickel alloy baseband, the composite baseband prepared by this method effectively improves the overall mechanical properties of the baseband. strength, but in this patent, high temperature and long time heat treatment are required after cold isostatic pressing, and the crystal grains tend to grow abnormally, resulting in a large amount of subsequent cold rolling deformation, and the composite billet obtained by cold isostatic pressing There are many holes on the surface and poor compactness, which seriously affects the subsequent epitaxial growth transition layer and superconducting layer; the cost of spark plasma sintering is too high, not suitable for industrial production

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