Nb_(3)Sn超导线材中Ta层的去除及腐蚀机理  

Removal of Tantalum Layer from Nb_(3)Sn Superconducting Wire and Corrosion Mechanism

作　　者：高瞻 张泽荣[2] 程军胜 王秋良[2,3] GAO Zhan;ZHANG Zerong;CHENG Junsheng;WANG Qiuliang(School of Rare Earths,University of Science and Technology of China,Hefei 230026,China;Ganjiang Innovation Academy,Chinese Academy of Sciences,Ganzhou 341119,China;Institute of Electrical Engineering,Chinese Academy of Sciences,Beijing 100190,China)

机构地区：[1]中国科学技术大学稀土学院,合肥230026 [2]中国科学院赣江创新研究院,赣州341119 [3]中国科学院电工研究所,北京100190

出　　处：《金属学报》2024年第7期968-976,共9页Acta Metallurgica Sinica

基　　金：中国科学院赣江创新研究院自主部署项目No.E055C003。

摘　　要：高质量的超导接头对于超导磁体的建造和后期稳定运行有着关键的作用。然而,针对Nb_(3)Sn线材,常常因为内部Ta阻挡层的存在而影响超导接头的制备。为了探究Nb_(3)Sn超导线材中Ta阻挡层的去除方法,选取内锡法制备的Nb_(3)Sn超导线材为实验对象,研究了线材在HF溶液、HF气氛、HF和H_(2)O_(2)混合溶液以及HF和HNO_(3)混合溶液中的腐蚀行为和特征,利用SEM和OM分析了线材微观结构和腐蚀形貌。结果表明,Ta层在HF和HNO_(3)混合溶液中腐蚀最快,在HF和H_(2)O_(2)混合溶液中次之,在HF气氛中较慢,在HF溶液中最慢。综合腐蚀后效果,采用HF和H_(2)O_(2)混合溶液进行腐蚀是去除Nb_(3)Sn超导线材中Ta阻挡层的最佳方法。同时,选取高纯Ta片为研究对象,分别在上述介质中进行腐蚀实验,并通过OM、XRD和XPS观察和分析试样腐蚀形貌、物相结构变化和腐蚀溶液中的元素价态,揭示了Ta的腐蚀机理,氧化剂的存在可以通过加快Ta表面Ta_(2)O_(5)膜的形成来加快HF对Ta的腐蚀速率。High-quality superconducting joints play a key role in the construction and stable operation of superconducting magnets.The preparation of superconducting joints for Nb_(3)Sn wires is often affected by the presence of an internal tantalum barrier layer.Thus,this study examined the effectiveness of different removal methods of the Ta barrier layer in Nb_(3)Sn superconducting wire.For this,the superconducting wire prepared by an internal tin method was considered as the experimental object,and the corrosion behavior and characteristics of the wire in HF solution,HF atmosphere,mixed solution of HF and H_(2)O_(2),and mixed solution of HF and HNO_(3) were investigated.The microstructure and corrosion morphology of the wire were analyzed using SEM and OM.Furthermore,high-purity Ta sheets were selected as the research object,and corrosion experiments were carried out in the above-mentioned media.The corrosion morphology,phase structure,and valence state of the elements of the specimens were analyzed using OM,XRD,and X-ray photoelectron spectroscopy(XPS)to reveal the corrosion mechanism of Ta.The results showed that the corrosion of the Ta layer was the fastest in the mixed solution of HF and HNO_(3),followed by the mixed solution of HF and H_(2)O_(2),the HF atmosphere,and then the HF solution.Based on the effect after corrosion,the mixed solution of HF and H_(2)O_(2) was found to be the best method to remove the Ta barrier layer in Nb_(3)Sn superconducting wire.Moreover,the presence of an oxidation agent can accelerate the corrosion rate of Ta by HF by accelerating the formation of Ta_(2)O_(5) film on the Ta surface.

关 键 词：Nb_(3)Sn超导线 超导接头 TA HF腐蚀 

分 类 号：TG172.6[金属学及工艺—金属表面处理]