| Autor: |
Ruoxu Wang, Lubei Liu, Zongheng Xue, Teng Tan |
| Jazyk: |
angličtina |
| Rok vydání: |
2023 |
| Předmět: |
|
| Zdroj: |
Archives of Metallurgy and Materials, Vol vol. 68, Iss No 4, Pp 1623-1632 (2023) |
| Druh dokumentu: |
article |
| ISSN: |
2300-1909 |
| DOI: |
10.24425/amm.2023.146232 |
| Popis: |
This paper introduces an approach for vacuum brazing of niobium-316L stainless steel transition joints for application in superconducting radiofrequency cavity helium jackets. The study takes advantage of good wettability of Ag-Cu-Pd brazing alloy to suppress brittle Fe-Nb intermetallic formation, hence improve the joints’ mechanical performance. The wettability of Ag-Cu-Pd filler metal on niobium, the interface microstructure and mechanical properties of the transition joints were investigated. Two kinds of Ag-Cu-Pd filler metals had been studied and wet well on the niobium, and the wettability of Ag-31.5Cu-10Pd filler metal on niobium was better than Ag-28Cu-20Pd filler metal. Microstructure characterization demonstrated the absence of brittle intermetallic layers in all of the joint interfaces. Mechanical properties of samples prepared with Ag-31.5Cu-10Pd filler metal were also better than their peers made with Ag-28Cu-20Pd filler metal both room temperature (300 K) and liquid nitrogen temperature (77 K). The transition joints displayed shear strengths of 356-375 MPa at 300 K and 440-457 MPa at 77 K, respectively. After undergoing ten thermal cycles between the room temperature and the liquid nitrogen temperature, the transition joints’ leak rates were all lower than 1.1×10 –11 mbar·L/s. Therefore, Ag-Cu-Pd filler metal is applicable to high vacuum vessels used at cryogenic temperatures. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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