TU1无氧铜钎料制备铌和316L不锈钢接头的微观组织和力学性能  

Microstructure and Mechanical Properties of Niobium and 316L Stainless Steel Joints by TU1 Oxygen Free Copper Brazing

作　　者：王若旭[1,2,3] 黄玉璐 蒋天才 郭浩[1] 熊平然[1] 谭腾 岳伟明 张周礼[1] 何源[1] 张兴义[2,3] Wang Ruoxu;Huang Yulu;Jiang Tiancai;Guo Hao;Xiong Pingran;Tan Teng;Yue Weiming;Zhang Zhouli;He Yuan;Zhang Xingyi(Institute of Modern Physics,Chinese Academy of Sciences,Lanzhou 730000,China;College of Civil Engineering and Mechanics,Lanzhou University,Lanzhou 730000,China;Key Laboratory of Mechanics on Disaster and Environment in Western China Attached to the Ministry of Education of China,Lanzhou University,Lanzhou 730000,China)

机构地区：[1]中国科学院近代物理研究所,甘肃兰州730000 [2]兰州大学土木工程与力学学院,甘肃兰州730000 [3]兰州大学西部灾害与环境力学教育部重点实验室,甘肃兰州730000

出　　处：《稀有金属材料与工程》2021年第4期1166-1172,共7页Rare Metal Materials and Engineering

基　　金：National Natural Science Foundation of China(11872196);Key Research Project of Frontier Science from Chinese Academy of Sciences(QYZDYSSW-JSC019)。

摘　　要：采用TU1无氧铜作为填充材料进行了反应堆级铌与316L不锈钢连接的真空钎焊,研究了样品和过渡接头在不同温度下的显微组织和力学性能。显微组织表明形成了脆的金属间化合物层并观察到结合面有扩散现象发生。虽然在结合面有脆性金属间化合物形成,但并不影响其在超导射频(SRF)腔中的使用。在室温(300 K)和液氮温度(77 K)下进行了拉伸测试和剪切测试。在液氮温度下,抗张强度高于其在室温下的抗张强度,由于脆性金属间化合物的存在导致其在液氮环境下抗剪切强度低于室温环境。由于我们严格控制焊缝厚度,使过渡接头的抗剪切强度高于样品的强度。最后我们对过渡接头进行真空漏率测试。结果显示,其真空漏率均低于1.1×10^(-9) Pa·L/s,这表明真空钎焊技术适用于低温下使用的高真空容器,例如用于SRF腔的不锈钢氦容器。A vacuum brazing technique was used to braze reactor grade niobium and 316 L stainless steel with oxygen-free copper as filler materials. Microstructure and mechanical properties of both samples and transition joints at different temperatures were investigated. Results demonstrate that brittle intermetallic layer forms and diffusion phenomenon is observed. In spite of the existence of brittle intermetallic, the brazing joints’ application in superconducting radio frequency(SRF) cavities is not affected. Mechanical tests including tensile tests and shear tests were conducted both at room temperature(300 K) and liquid nitrogen temperature(77 K). The tensile strengths at liquid nitrogen temperature are higher than at room temperature, while the shear strengths are reduced due to the formation of brittle intermetallic. The transition joints always have higher mechanical strengths than samples when the thickness of the brazing seam is strictly controlled. Leak tests were also performed on the transition joints. The joints’ leak rates are all lower than1.1×10^(-9) Pa·L/s, indicating that the vacuum brazing technology is applicable to high vacuum vessels used at cryogenic temperatures,such as stainless steel helium vessel for SRF cavities.

关 键 词：钎焊 铌 不锈钢 无氧铜 超导射频腔 

分 类 号：TG454[金属学及工艺—焊接]