| 摘要 |
PURPOSE: A method for refining niobium alloy having ultra-high purity is provided which is applied to superconductor through getter agent and a new heat treatment in which refining is performed within a short period of time by simple operation. CONSTITUTION: The method comprises a step of covering a niobium alloy(5) to be refined with a foil formed of Ti, covering the Ti foil(3) with a Mo foil again, and charging the niobium alloy covered with the Ti foil and the Mo foil into a quartz tube(1) so that it is vacuum sealed in the quartz tube; a step of forming a getter agent deposition layer(7) by depositing Ti on the surface of the niobium alloy using the Ti foil as a getter agent by heat treating the quartz tube in the temperature range of 1,100 to 1,190 deg.C for 10 to 24 hours; and a step of removing a thin film deposited on the surface of the niobium alloy by rapidly cooling the quartz tube, wherein the quartz tube is vacuumed to 10¬-2 torr or less, wherein the getter agent is deposited to a thickness of 20 μm or more on the surface of the niobium alloy, and wherein the thin film is removed by impregnating the thin film deposited on the surface of the niobium alloy with a mixed solution of NH3 and HF.
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