摘要
研究了Bi-2223/Ag高温超导带材的前驱粉与后续热处理工艺之间的匹配问题。实验采用A,B,C3种不同的前驱粉。A粉是成分配比为2223的喷雾热分解单粉,B粉和C粉都是2212加CaCuOy组分的2223双粉。B粉和C粉的区别在于,2212加CaCuOy混合后的除碳处理工艺不同。B粉为800℃,3h,C粉为830℃,10h。利用激光粒度分析仪(RSA)和扫描电镜(SEM)对这3种前驱粉的粒度进行了表征,并用X射线衍射仪(XRD)对用这3种粉分别制成的带材经第1次热处理(HT1)后的2223成相率和相结构进行分析,从而找出它们各自对应的最佳HT1工艺。采用四引线法在77K,0T下测试经中间轧制和第2次热处理(HT2)后的临界电流(Ic),以确定其对应之最佳HT2工艺。RSA和SEM分析表明:A粉颗粒度明显细小,平均中径粒度为1.5μm,且粒径分布区域集中,B粉约3μm,粒径分布较分散,而C粉为4￣5μm。研究结果证明:前驱粉的特性直接影响着超导带材的最终超导性能。一种特定的前驱粉,对应着一种特定的最佳HT1和HT2工艺。只有在二者匹配良好前提下,才能使前驱粉的性能得以发掘。
The matter of match between precursor powder and consequent heat treatment for Bi-2223/Ag superconducting strip was reported. Three kinds of different precursor powder A, B, and C were used for experiment, in which A is pyrolytic spray powder with unique component, B and C are composite powder consisted of 2212 and CaCu Oy treated by 800 ℃, 3 h and 830 ℃, 10 h respectively. The particle size of three kinds of powder was characterized by RSA and SEM. After first heat treatment （HT1）, the strips made from powder A, B, C respectively were analyzed for 2223 phase ratio and phase structure in order to find optimum HT1 process. After intermediate rolling and second heat treatment, the Ic of the strips was measured by four leads method at 77 K, 0 T in order to find corresponding optimum HT2 process. The results of RSA and SEM show that powder A has obviously fine particle size, 2 μm in average, and narrow particle size distribution; powder B 5μm in average and wide particle size distribution; powder C 6-7 μm in average.
出处
《稀有金属快报》
CSCD
2006年第7期27-30,共4页
Rare Metals Letters
