EN 61788-12-2013 en Superconductivity - Part 12 Matrix to superconductor volume ratio measurement - Copper to non-copper volume ratio of Nb3Sn composite superconducting wires.pdf

1、BSI Standards PublicationSuperconductivityPart 12: Matrix to superconductor volume ratio measurement Copper to non-copper volume ratio of Nb3Sncomposite superconducting wiresBS EN 61788-12:2013National forewordThis British Standard is the UK implementation of EN 61788-12:2013. It isidentical to IEC

2、61788-12:2013. It supersedes BS EN 61788-12:2002 which iswithdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee L/-/90, Super Conductivity.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport

3、 to include all the necessary provisions ofa contract. Users are responsible for its correct application. The British Standards Institution 2013.Published by BSI Standards Limited 2013ISBN 978 0 580 75669 6ICS 29.050 Compliance with a British Standard cannot confer immunity fromlegal obligations.Thi

4、s British Standard was published under the authority of theStandards Policy and Strategy Committee on 31 October 2013.Amendments/corrigenda issued since publicationDate Text affectedBRITISH STANDARDBS EN 61788-12:2013EUROPEAN STANDARD EN 61788-12 NORME EUROPENNE EUROPISCHE NORM October 2013 CENELEC

5、European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung CEN-CENELEC Management Centre: Avenue Marnix 17, B - 1000 Brussels 2013 CENELEC - All rights of exploitation in any form and by any means reserved

6、worldwide for CENELEC members. Ref. No. EN 61788-12:2013 E ICS 29.050 Supersedes EN 61788-12:2002 English version Superconductivity - Part 12: Matrix to superconductor volume ratio measurement - Copper to non-copper volume ratio of Nb3Sn composite superconducting wires (IEC 61788-12:2013) Supracondu

7、ctivit - Partie 12 : Mesure du rapport volumique matrice/supraconducteur - Rapport volumique cuivre/non-cuivre des fils en composite supraconducteur Nb3Sn (CEI 61788-12:2013) Supraleitfhigkeit - Teil 12: Messung des Verhltnisses von Matrixvolumen zu Supraleitervolumen - Verhltnis des Kupfervolumens

8、zum kupferfreien Volumen von Nb3Sn-Verbundsupraleiterdrhten (IEC 61788-12:2013) This European Standard was approved by CENELEC on 2013-07-17. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a

9、 national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CENELEC member. This European Standard exists in three official versions (English, French, Germa

10、n). A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CENELEC members are the national electrotechnical committees of Austria, Belgium,

11、 Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Sw

12、itzerland, Turkey and the United Kingdom. BS EN 61788-12:2013EN 61788-12:2013 - 2 - Foreword The text of document 90/322/FDIS, future edition 2 of IEC 61788-12, prepared by IEC/TC 90 “Superconductivity“ was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as EN 61788-12:2013. The f

13、ollowing dates are fixed: latest date by which the document has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 2014-04-17 latest date by which the national standards conflicting with the document have to be withdrawn (dow) 2016-07-17 This

14、 document supersedes EN 61788-12:2002. EN 61788-12:2013 includes the following significant technical changes with respect to EN 61788-12:2002: The main revision is the addition of two new annexes, “Uncertainty considerations“ (Annex H) and “Uncertainty evaluation in the test method of the copper to

15、non-copper volume ratio of Nb3Sn composite superconducting wires“ (Annex I). Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CENELEC and/or CEN shall not be held responsible for identifying any or all such patent rights. Endorseme

16、nt notice The text of the International Standard IEC 61788-12:2013 was approved by CENELEC as a European Standard without any modification. BS EN 61788-12:2013- 3 - EN 61788-12:2013 Annex ZA (normative) Normative references to international publications with their corresponding European publications

17、 The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. NOTE W

18、hen an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD applies. Publication Year Title EN/HD Year IEC 60050 Series International Electrotechnical Vocabulary (IEV) - - IEC 61788-5 - Superconductivity - Part 5: Matrix to superconductor volume

19、 ratio measurement - Copper to superconductor volume ratio of Cu/Nb-Ti composite superconductors EN 61788-5 - BS EN 61788-12:2013 2 61788-12 IEC:2013 CONTENTS INTRODUCTION . 6 1 Scope . 7 2 Normative references . 7 3 Terms and definitions . 7 4 Principle . 8 5 Apparatus . 8 6 Measurement procedure .

20、 8 Preparation of specimen 8 6.1General . 8 6.1.1Procedures 8 6.1.2Measurement 9 6.2Photo of cross-section . 9 6.2.1Transfer . 9 6.2.2Cutting. 9 6.2.3Measurement of paper mass 9 6.2.4Test procedure for the second specimen . 9 6.3Paper mass . 9 6.47 Calculation of results 9 8 Uncertainty of the test

21、method 10 9 Test report 10 Copper to non-copper volume ratio 10 9.1Identification of test specimen . 10 9.2Annex A (normative) Measurement Image processing method . 11 Annex B (normative) Measurement Copper mass method 12 Annex C (normative) Measurement method using planimeter 13 Annex D (informativ

22、e) Specimen polishing method . 14 Annex E (informative) Difference of the copper to non-copper volume ratio before and after the Nb3Sn generation heat treatment process 15 Annex F (informative) Paper mass bias at copy 16 Annex G (informative) Cross-sections of Cu/Nb3Sn wires . 17 Annex H (informativ

23、e) Uncertainty considerations . 18 Annex I (informative) Uncertainty evaluation in the test method of the copper to non-copper volume ratio of Nb3Sn composite superconducting wires 23 Figure G.1 Cross-sections of four Cu/Nb3Sn wire types according to the layout of the stabilizer . 17 BS EN 61788-12:

24、201361788-12 IEC:2013 3 Table H.1 Output signals from two nominally identical extensometers 19 Table H.2 Mean values of two output signals . 19 Table H.3 Experimental standard deviations of two output signals . 19 Table H.4 Standard uncertainties of two output signals 20 Table H.5 Coefficient of var

25、iations of two output signals 20 BS EN 61788-12:2013 6 61788-12 IEC:2013 INTRODUCTION The copper to non-copper volume ratio of superconducting wires serves as an important numeric value used when determining the critical current density and its stability, which are two of the important characteristi

26、cs of superconducting wires. This standard is concerned with the standardization of the test method for the copper to non-copper volume ratio of copper stabilized Nb3Sn multi-filamentary composite superconducting wires (hereinafter referred to as Cu/Nb3Sn wires). Cu/Nb3Sn wires can be classified int

27、o four types according to the layout of the stabilizer as shown in Annex G: the external stabilizer type, the internal stabilizer type, the distributed stabilizer type and the contiguous stabilizer with distributed barrier type. The test method specified by this standard may be applicable to a type

28、whose cross-section is of the external stabilizer or the internal stabilizer type regardless of the production process employed. With regard to the internal stabilizer type, the internal structure of some Cu/Nb3Sn wires prevents copper from being dissolved and removed. This precludes the application

29、 of the copper mass method, unlike with copper matrix Nb-Ti superconducting wires. New methods are therefore needed, as detailed in the following: the paper mass method, where a photo of the cross-section of the wire being measured is traced onto tracing paper, or a copy is made of the photo using a

30、 copying machine; the paper is then cut out into different portions to measure the mass of each piece of paper; the image processing method, where the image of the photo of the cross-section is digitized and the areas are analyzed with software; the copper mass method, where the copper of the specim

31、en is dissolved in nitric acid solution to leave only the non-copper portion, and to measure the mass of the specimen and the non-copper portion of specimen. This standard is concerned with the paper mass method which is adopted more generally. As supplementary methods, the image processing method a

32、nd the copper mass method adopted for Cu/Nb3Sn wires are specified in Annex A and Annex B, respectively. The method using a planimeter is specified in Annex C. In Annex D an example of a polishing method is also specified. BS EN 61788-12:201361788-12 IEC:2013 7 SUPERCONDUCTIVITY Part 12: Matrix to s

33、uperconductor volume ratio measurement Copper to non-copper volume ratio of Nb3Sn composite superconducting wires 1 Scope This part of IEC 61788 describes a test method for determining the copper to non-copper volume ratio of Cu/Nb3Sn wires. The test method given hereunder is applicable to Nb3Sn com

34、posite superconducting wires with a cross-sectional area of 0,1 mm2 to 3,0 mm2 and a copper to non-copper volume ratio of 0,1 or more. It does not make any reference to the filament diameter; however, it is not applicable to those superconducting wires with their filament, Sn, Cu-Sn alloy, barrier m

35、aterial and other non-copper portions dispersed in the copper matrix or those with the stabilizer dispersed. Furthermore, the copper to non-copper volume ratio can be determined on specimens before or after the Nb3Sn formation heat treatment process. The Cu/Nb3Sn wire has a monolithic structure with

36、 a round or rectangular cross-section. Though uncertainty increases, this method may be applicable to the measurement of the copper to non-copper volume ratio of the Cu/Nb3Sn wires whose cross-section and copper to non-copper volume ratio fall outside the specified ranges. This test method may be ap

37、plied to other composite superconducting wires after some appropriate modifications. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For u

38、ndated references, the latest edition of the referenced document (including any amendments) applies. IEC 60050 (all parts), International Electrotechnical Vocabulary (available at IEC 61788-5, Superconductivity Part 5: Matrix to superconductor volume ratio measurement Copper to superconductor volume

39、 ratio of Cu/Nb-Ti composite superconductors 3 Terms and definitions For the purposes of this document, the terms and definitions given in IEC 60050-815 as well as the following apply. 3.1copper to non-copper volume ratio ratio of the volume of the copper stabilizing material to the volume without c

40、opper consisting of Cu/Nb3Sn wires BS EN 61788-12:2013 8 61788-12 IEC:2013 4 Principle The principle of this method is described in the following. A photo of the polished cross-section of the sample wire shall be taken with a metallograph. This photo is traced onto tracing paper, or a copy is made o

41、f the photo using a copy machine. The tracing paper or copy is then cut out into different portions to measure the mass of each piece of paper. The copper to non-copper volume ratio can be obtained from the ratio of the paper mass of both portions. 5 Apparatus The apparatus required for the test inc

42、ludes the following: metallograph; photomicrographic camera; polishing machine; balance; A balance shall have a manufacturers specified uncertainty of 0,1 mg or better. scissors or cutter. 6 Measurement procedure Preparation of specimen 6.1General 6.1.1The specimen shall be prepared from a Cu/Nb3Sn

43、wire before or after the Nb3Sn generation heat treatment process. Two specimens shall be cut out of a Cu/Nb3Sn wire being measured. NOTE In the case of measuring an internal tin processed wire before the treatment, the stabilizer copper is carefully distinguished from copper in other parts. Procedur

44、es 6.1.26.1.2.1 Mold The two specimens shall be molded at the same time for polishing. As the molding material, an appropriate resin shall be used to embed the specimen for observation through the metallograph. When molding, it shall be carefully checked that the cross-section of the specimen is at

45、right angles to the polishing surface as much as possible. 6.1.2.2 Polishing The specimen shall be polished using emery paper and buffed using an abrasive material. A microscope shall be used to check that the polished surface is smooth enough to ensure good photographing, especially the boundary be

46、tween the copper and non-copper portions and the periphery of the sample. The surface shall be re-polished, if these areas are not clear because of abrasive scratches. An example of the polishing method is specified in Annex D. 6.1.2.3 Cleaning and drying The polished specimen shall be cleaned using

47、 running water, distilled water, acetone or ethyl alcohol. It shall be checked that the cleaning agent does not dissolve the resin in which the specimen is embedded. An ultrasonic cleaning machine may be used if necessary. After cleaning, the specimen shall be dried with chilled or hot air to preven

48、t the polished surface from oxidizing or discoloring. BS EN 61788-12:201361788-12 IEC:2013 9 Measurement 6.2Photo of cross-section 6.2.1A black-and-white or color picture of the cross-section shall be taken using the metallograph. The magnification shall be selected for the entire cross-section of t

49、he specimen to fit within the size of the photo. A photomicrographic camera with as much depth of focus as possible shall be used, so that the boundary between copper and non-copper portions and the periphery of the specimen appear clear and vivid on the photo. Transfer 6.2.2The image of the cross-section shall be traced on tracing paper so that the copper portion and non-copper portion can be separated. As an alternative method, a copy of the photo of the cross-section shall be made usi