【摘要】 以高均匀性Nb47Ti合金棒和高纯无氧铜为原材料,制备了铜比1.3,630芯的NbTi/Cu超导线。提出了一种新型时效热处理工艺"短时预时效热处理+高温长时间时效热处理",即"405℃/3 h+405℃/3 h+420℃/20 h+420℃/40h+420℃/80h"工艺,该工艺可显著提高NbTi超导线材的临界电流密度,较普通热处理线材提高近17.5%,最高可以达到3208A/mm~2。足够的预时效次数(2次)才能使基体中析出足够多的α形核数量,进而才能在较大的最终应变下显著提高临界电流密度。此外,在4.46,5.35,6.25 3种预应变条件之下,临界电流密度达到峰值的最终应变都集中在5.0~5.2之间,即,必须将最终应变控制在5.0~5.2。更多还原

【Abstract】 NbTi/Cu wire with the low copper-to-superconductor ratio of 1.3 and filament number of 630 was prepared using highly homogenous Nb47 Ti alloy bar and oxygen-free copper. A new type of aging heat treatment(405 °C/3 h+405 °C/3 h+420 °C/20 h+420 °C/40 h+420 °C/80 h) was proposed. Compared with the traditional heat treatment, this new type heat treatment can largely improve the critical current density of NbTi superconducting wire to 3208 A/mm2, with an increment of 17.5%. When the pre-heat treatment times are equal to or more than 2 times, enough nucleation can be formed and critical current density can be improved obviously. In addition, critical current densities of wire under three pre-strain conditions(4.46, 5.35 and 6.25) all get the peak value when final strain is between 5.0~5.2. So, the pre-strain should be controlled between 5.0~5.2.更多还原