| 摘要 |
1415269 Electro-depositing niobium by molten electrolysis SIEMENS AG 11 June 1974 [22 June 1973] 25938/74 Addition to 1408727 Heading C7B [Also in Division B3] In a process of making a composite wire (see Division B3), a sheath-like niobium layer is electro-deposited in an argon atmosphere on to a copper rod using a molten electrolyte heated to 740 C and containing K 2 NbF 7 , LiF, NaF and KF. A meshed screen for preventing impurities in the electrolyte affecting the process is positioned between the copper rod and a niobium anode. The external surface of the deposited niobium layer is smoothed by turning and after removing the copper rod, chemically or by machining, to leave a niobium tube, a small amount of material is removed from the internal surface of the niobium tube. The niobium tube is fitted on to an aluminium rod and the assembly is then drawn and suaged. |
