IEC 61788-6:2011

IEC 61788-6 ®
Edition 3.0 2011-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Superconductivity –
Part 6: Mechanical properties measurement – Room temperature tensile test
of Cu/Nb-Ti composite superconductors

Supraconductivité –
Partie 6: Mesure des propriétés mécaniques – Essai de traction à température
ambiante des supraconducteurs composites de Cu/Nb-Ti

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by
any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either IEC or
IEC's member National Committee in the country of the requester.
If you have any questions about IEC copyright or have an enquiry about obtaining additional rights to this publication,
please contact the address below or your local IEC member National Committee for further information.

Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduite
ni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie
et les microfilms, sans l'accord écrit de la CEI ou du Comité national de la CEI du pays du demandeur.
Si vous avez des questions sur le copyright de la CEI ou si vous désirez obtenir des droits supplémentaires sur cette
publication, utilisez les coordonnées ci-après ou contactez le Comité national de la CEI de votre pays de résidence.

IEC Central Office
3, rue de Varembé
CH-1211 Geneva 20
Switzerland
Email: inmail@iec.ch
Web: www.iec.ch
About the IEC
The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes
International Standards for all electrical, electronic and related technologies.

About IEC publications
The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the
latest edition, a corrigenda or an amendment might have been published.
 Catalogue of IEC publications: www.iec.ch/searchpub
The IEC on-line Catalogue enables you to search by a variety of criteria (reference number, text, technical committee,…).
It also gives information on projects, withdrawn and replaced publications.
 IEC Just Published: www.iec.ch/online_news/justpub
Stay up to date on all new IEC publications. Just Published details twice a month all new publications released. Available
on-line and also by email.
 Electropedia: www.electropedia.org
The world's leading online dictionary of electronic and electrical terms containing more than 20 000 terms and definitions
in English and French, with equivalent terms in additional languages. Also known as the International Electrotechnical
Vocabulary online.
 Customer Service Centre: www.iec.ch/webstore/custserv
If you wish to give us your feedback on this publication or need further assistance, please visit the Customer Service
Centre FAQ or contact us:
Email: csc@iec.ch
Tel.: +41 22 919 02 11
Fax: +41 22 919 03 00
A propos de la CEI
La Commission Electrotechnique Internationale (CEI) est la première organisation mondiale qui élabore et publie des
normes internationales pour tout ce qui a trait à l'électricité, à l'électronique et aux technologies apparentées.

A propos des publications CEI
Le contenu technique des publications de la CEI est constamment revu. Veuillez vous assurer que vous possédez
l’édition la plus récente, un corrigendum ou amendement peut avoir été publié.
 Catalogue des publications de la CEI: www.iec.ch/searchpub/cur_fut-f.htm
Le Catalogue en-ligne de la CEI vous permet d’effectuer des recherches en utilisant différents critères (numéro de référence,
texte, comité d’études,…). Il donne aussi des informations sur les projets et les publications retirées ou remplacées.
 Just Published CEI: www.iec.ch/online_news/justpub
Restez informé sur les nouvelles publications de la CEI. Just Published détaille deux fois par mois les nouvelles
publications parues. Disponible en-ligne et aussi par email.
 Electropedia: www.electropedia.org
Le premier dictionnaire en ligne au monde de termes électroniques et électriques. Il contient plus de 20 000 termes et
définitions en anglais et en français, ainsi que les termes équivalents dans les langues additionnelles. Egalement appelé
Vocabulaire Electrotechnique International en ligne.
 Service Clients: www.iec.ch/webstore/custserv/custserv_entry-f.htm
Si vous désirez nous donner des commentaires sur cette publication ou si vous avez des questions, visitez le FAQ du
Service clients ou contactez-nous:
Email: csc@iec.ch
Tél.: +41 22 919 02 11
Fax: +41 22 919 03 00
IEC 61788-6 ®
Edition 3.0 2011-07
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Superconductivity –
Part 6: Mechanical properties measurement – Room temperature tensile test
of Cu/Nb-Ti composite superconductors

Supraconductivité –
Partie 6: Mesure des propriétés mécaniques – Essai de traction à température
ambiante des supraconducteurs composites de Cu/Nb-Ti

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX V
ICS 29.050; 77.040.10 ISBN 978-2-88912-580-7

– 2 – 61788-6  IEC:2011
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 7
4 Principle . 8
5 Apparatus . 8
5.1 Conformity . 8
5.2 Testing machine . 8
5.3 Extensometer . 9
6 Specimen preparation. 9
6.1 Straightening the specimen . 9
6.2 Length of specimen . 9
6.3 Removing insulation . 9
6.4 Determination of cross-sectional area (S ) . 9
o
7 Testing conditions . 9
7.1 Specimen gripping . 9
7.2 Pre-loading and setting of extensometer . 9
7.3 Testing speed. 9
7.4 Test . 10
8 Calculation of results . 12
8.1 Tensile strength (R ) . 12
m
8.2 0,2 % proof strength (R and R ) . 12
p0,2A p0,2B
8.3 Modulus of elasticity (E and E ) . 12
o a
9 Uncertainty . 12
10 Test report. 13
10.1 Specimen . 13
10.2 Results . 13
10.3 Test conditions . 13
Annex A (informative) Additional information relating to Clauses 1 to 10 . 14
Annex B (informative) Uncertainty considerations . 19
Annex C (informative) Specific examples related to mechanical tests . 23
Bibliography . 32

Figure 1 – Stress-strain curve and definition of modulus of elasticity and 0,2 % proof
strengths . 11
Figure A.1 – An example of the light extensometer, where R1 and R3 indicate the
corner radius . 15
Figure A.2 – An example of the extensometer provided with balance weight and
vertical specimen axis . 16
Figure C.1 – Measured stress versus strain curve of the rectangular cross section NbTi
wire and the initial part of the curve . 23
Figure C.2 – 0,2 % offset shifted regression line, the raw stress versus strain curve
and the original raw data of stress versus strain . 29

61788-6  IEC:2011 – 3 –
Table B.1 – Output signals from two nominally identical extensometers . 20
Table B.2 – Mean values of two output signals . 20
Table B.3 – Experimental standard deviations of two output signals. 20
Table B.4 – Standard uncertainties of two output signals . 21
Table B.5 – Coefficient of variations of two output signals. 21
Table C.1 – Load cell specifications according to manufacturer’s data sheet . 26
Table C.2 – Uncertainties of displacement measurement . 26
Table C.3 – Uncertainties of wire width measurement . 27
Table C.4 – Uncertainties of wire thickness measurement . 27
Table C.5 – Uncertainties of gauge length measurement . 27
Table C.6 – Calculation of stress at 0 % and at 0,1 % strain using the zero offset
regression line as determined in Figure C.1b). . 28
Table C.7 – Linear regression equations computed for the three shifted lines and for
the stress versus strain curve in the region where the lines intersect . 29
Table C.8 – Calculation of strain and stress at the intersections of the three shifted
lines with the stress strain curve . 30
Table C.9 – Measured stress versus strain data and the computed stress based on a
linear fit to the data in the region of interest . 31

– 4 – 61788-6  IEC:2011
INTERNATIONAL ELECTROTECHNICAL COMMISSION
_____________
SUPERCONDUCTIVITY –
Part 6: Mechanical properties measurement –
Room temperature tensile test of Cu/Nb-Ti
composite superconductors
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the
...