Optimization of Cross-sectional Shapes of the Bi-2223/Ag Wires before Flat Rolling

来源 :Chinese Journal of Mechanical Engineering | 被引量 : 0次 | 上传用户:oliver777
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
Rolling process plays an important role in the manufacture of Bi-based high temperature superconductor tapes, and the plastic flow regularities of the superconducting wires during deformation will directly affect the ultimate quality of the tapes. In order to investigate the effect of cross-sectional shapes before flat rolling on the performance and homogeneity of the tapes, some numerical models of Bi-2223/Ag wires with different cross-sectional shapes including circular, square, elliptical and racetrack cross-sections are constructed during the rolling process. By comparing the relative density, logarithmic strain ratio and length-width ratio on the filaments, it is revealed that Bi-2223/Ag wire with special-shaped cross-section can achieve better conductivity than the round wire, in particular, the racetrack cross-sectional wire has the second best performance among four wires. Based on material processability and experimental condition, tri-pass racetrack drawing technique is employed to optimize the process and obtain racetrack cross-sectional wire. The rolling process of Bi-2223/Ag wire with racetrack cross-section causes more intensive deformation of filaments in the center of the tape and achieves the filaments with larger length-width ratio. Also, the deformation distribution of filaments verifies the numerical results. Consequently, the racetrack drawing technique can be utilized for a reference during the mechanical processing and to increase the current transmission capacities of Bi-2223/Ag tapes. Rolling process plays an important role in the manufacture of Bi-based high temperature superconductor tapes, and the plastic flow regularities of the superconducting wires during deformation will directly directly affect the ultimate quality of the tapes. In order to investigate the effect of cross-sectional shapes before flat rolling on the performance and homogeneity of the tapes, some numerical models of Bi-2223 / Ag wires with different cross-sectional shapes including circular, square, elliptical and racetrack cross-sections are constructed during the rolling process. By comparing the relative density, logarithmic strain ratio and length-width ratio on the filaments, it is revealed that Bi-2223 / Ag wire with special-shaped cross-section can achieve better conductivity than the round wire, in particular, the racetrack cross-sectional wire has the second best performance among four wires. Based on material processability and experimental condition, tri-pass racetrack drawing technique is emplo yed to optimize the process and obtain racetrack cross-sectional wire. The rolling process of Bi-2223 / Ag wire with racetrack cross-section causes more intensive deformation of filaments in the center of the tape and achieves the filaments with larger length-width ratio Also, the deformation distribution of filaments verifies the numerical results. The racetrack drawing technique can be utilized for a reference during the mechanical processing and to increase the current transmission capacities of Bi-2223 / Ag tapes.
其他文献
在幼儿教育中,情感教育能促进幼儿健康、全面地发展,而幼儿期正是情感教育的关键时期,幼儿教师在情感教育中的积极性评价,会更加尊重幼儿、关爱幼儿、保护幼儿。在幼儿情感教
期刊
结合多年的教学经验,探讨中考政治问答题解题的方法与步骤,总结解题的注意事项,以使考生掌握解题技巧,提高解题能力。 Combined with years of teaching experience, to dis
树立以学生为主的教学观念,改进教学方法和教学手段,组织丰富多彩的教学实践活动,为学生学习营造一个兴趣盎然的良好环境,能够激发学生学习历史的兴趣.这已是教育界同仁的共
鸡西矿业集团公司张辰煤矿西三采区3
期刊
编辑同志: 我以极其兴奋的心情,向您们报告一个好消息,我团已经提前八十六天完成了全年二百场的演出任务,这是英明领袖华主席抓纲治国的结果。在毛主席的“百花齐放,推陈出
大直径低位错密度InSb单晶研制叶真吉,陶世端,李忠良(昆明物理研究所昆明650223)本文介绍了采用国产低熔点化合物单晶炉,首次成功生长大直径低位错密度InSb单晶。单晶参数为:尺寸:35~42mm晶体生长方向:<111>、<211>、
本文研究了硅双极晶体管电流增益和截止频率的低温物理特性,提出了电流增益在低温下将随发射区杂质浓度的下降和基区杂质浓度的上升而上升的新理论,得出了低温下硅中浅能级杂质
随着教育的不断发展,人们把更多的目光投向其中。虽说学习仍是主要任务,而中学生在校情况,如同学间交往也得到社会的普遍关注。通过对相应学术研究资料的翻阅,我们发现对异性
袁纯清书记在全省领导干部大会的讲话吹响了我省在新起点上转型发展、跨越发展的进军号。各级纪检监察干部一定要把思想统一到实现跨越发展的大局上,把智慧凝聚到推动跨越发
三省话剧汇演开幕了。这是对三十多年来,尤其是三中全会以来东北地区话剧运动的总结和检阅。汇演在这一历史时刻举行,有着其特殊的意义。近年来,由于多种因素使然,舞台剧的