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时间:2020-05-01
《MRI用低铜比NbTi超导线材组织和性能.pdf》由会员上传分享,免费在线阅读,更多相关内容在行业资料-天天文库。
1、第36卷第5期低温物理学报V0l_36。No.52014年lO月CHINESEJOURNALOFLOWTEMPERATUREPHYSICSOctorber2014MRI用低铜比NbTi超导线材组织和性能*郭强李建峰王庆相。闫凯娟朱燕敏刘建伟L刘向宏。冯勇L张平祥。西部超导材料科技股份有限公司,西安710018;超导材料制备国家工程实验室,西安710018;。西北有色金属研究院,西安710016收稿日期:2014—04—11;修回日期:2014—05—17【摘要】本文以高均匀性Nb47Ti合金锭和高纯无氧铜为原材料,制备了
2、铜比为1.0,~p0.846mm的MRI(MagneticResonanceImaging)用低铜比NbTi/Cu超导线.研究了最终应变和间隔应变对MRI用NbTi/Cu超导线微观组织和临界电流密度的影响.测试结果表明:时效3次时,最终应变在3.O~4.4之间,随最终应变增大,临界电流密度呈先增大而后降低,最终趋于稳定的变化规律;最终应变相同的条件下,增大间隔应变会导致临界电流密度的降低.经过工艺优化后,临界电流密度最高为3208A/m1n2(4.2K,5T,判据0.1t~V/cm).微观组织观察表明:临界电流密度最高时
3、,—Ti沉淀相呈褶皱弯曲状,并弥散的分布在p-NbTi基体之上.关键词:NbTi/Cu超导线,临界电流密度,—Ti沉淀相,最终应变,间隔应变PACC:7400,7430F,7460M,7470MICRoSTRUCTUREANDPRoPERTYoFMRINbTiSUPERCoNDUCTINGWIREQiangGUO'JianfengLI’QingxiangWANG’。KaijuanYAN,YanminZHU’JianweLIUi'XianghongLIU'YongFENG,WesternSuperconductingTec
4、hnologiesCo.,LTD,Xi’an710018;NationalEngineeringLaboratoryforSuperconductingMaterials,Xi’an710018;。NorthwestInstituteforNon—ferrousMetalResearch。Xi’an710016Receiveddate:2014—04—11;revisedmanuscriptreceiveddate:2014—05—17[Abstract]Inpresentpaper,NbTi/Cuwirewiththe
5、copper-to-superconductorratioof1.0waspreparedusinghighhomogenousNb47Tialloybarandoxygen-freecopperfirstly.TheeffectoffinalstrainandintervalstrainonthemicrostructureandcriticalcurrentdensityofNbTisuperconductingwirewasinvestigated.Itcanbedrawnfromalotofexperiments
6、thatfor3timesheattreatments,criticalcurrentdensityraisedfirstly,andthendescendedtOastablevalueasthefinaldrawingstrainvariesfrom3.0to4.4.Inaddition,improvingtheintervalstrainbetweenheattreatmentsresultedinthedeclineofcriticalcurrentdensitywhilethefinalstrainiSfixe
7、d.Measurementresultsshowthattheacquiredmaximumcriticalcurrentdensitycanreach3208A/mm2at4.2Kand5T(criterion:0.1vV/cm).TEMobservationsshowedthata-TiprecipitatesdispersedwithinthesuperconductingNbTimatrixwith国家863专项(批准号:2Ol4AAO327O1)资助课题.Projectsupportedbythenationa
8、l863project(grantNo.2014AAo327O1).325guoqiang@163.corn第5期郭强,等:MRI用低铜比NbTi超导线材组织和性能347strongfoldandcurlfortheNbTiwirewithhighestcriticalcurrentdensityat4.2K.Key
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