【摘要】 本文研究了热处理对实用多芯Nb,Sn超导体的影响.在(650—750℃热处理时,Nb₃Sn层厚度Y与时间t可用Y∞t⁷²关系表示,这里0.130≤n≤0.195.多芯复合材料在热处理过程中,Cu-Sn基体中Sn量消耗显著地影响Nb₃Sn生长速率,考虑了这一因素的Nb₃Sn生长动力学修正公式能对实验结果进行解释.700℃热处理10—100小时,Nb₃Sn品粒尺寸是热处理时间的一个函数。晶粒大小随热处理时间增长而增大,并且∞t^m,m=0.205.对于锡青铜基体与铌比值分别为1.84和3.05的两种导体,在700℃热处理时,其临界电流是热处理时间的一个函数.I_c（t）中最大值取决于Nb₃Sn层增厚和晶粒度长大的综合效果.T_c随热处理时间增长和温度升高而峪有提高.这大概与Nb₃Sn层化学计量比有关.更多还原

【Abstract】 Investigation is made on the effect of heat treatment on practical multifilamentary Nb3Sn superconductors. At 650℃-750℃ during heat treatment, the thickness T of Nb3Sn layer is expressed by the equation T∞tn, where 0.130≤n≤0.195. The depletion of Sn contents in the Cu-Sn matrix of multifilamentary composites during heat treatment produces a great effect on the growth rate. The revised formula of growth kinetics gives a satisfactory explanation on the experimental results. The Nb3Sn grain size, is shown as a function of treatment time when heat-treated at 700℃ for from 10 to 100 hours. That is, the grain size (L) increases with heat-treatment time; and, L∞tm, where m = 0.205. The critical currents for two conductors with different ratios of niobium to Sn-bronze matrix (1:1.84 and 1: 3.05) are shown as a function of heat-treatment time at 700℃ temperature. The maxima which are observed in I, with respect to time are due to the competing processes which determines Ic, i. e. layer thickness and grain growth. The critical temperature Tc increases slightly with heat-treatment time and temperature, this increase being probably associated with stoichiometry of Nb3Sn layer.更多还原