EN ISO 18608:2022

SLOVENSKI STANDARD
01-junij-2022
Nadomešča:
SIST EN 13234:2007
Fina keramika (sodobna keramika, sodobna tehnična keramika) - Mehanske
lastnosti keramičnih kompozitov pri temperaturi okolice in pri zračnem tlaku -
Ugotavljanje odpornosti proti širjenju razpoke s preskušanjem občutljivosti zareze
(ISO 18608:2017)
Fine ceramics (advanced ceramics, advanced technical ceramics) - Mechanical
properties of ceramic composites at ambient temperature in air atmospheric pressure -
Determination of the resistance to crack propagation by notch sensitivity testing (ISO
18608:2017)
Hochleistungskeramik - Mechanische Eigenschaften von keramischen
Verbundwerkstoffen bei Umgebungstemperatur in Luft unter atmosphärischem Druck -
Bestimmung der Rissausbreitungsbeständigkeit durch die Kerbempfindlichkeitsprüfung
(ISO 18608:2017)
Céramiques techniques - Propriétés mécaniques des céramiques composites à
température ambiante sous pression atmosphérique - Détermination de la résistance à
la propagation de fissure par un essai de sensibilité à l'entaille (ISO 18608:2017)
Ta slovenski standard je istoveten z: EN ISO 18608:2022
ICS:
81.060.30 Sodobna keramika Advanced ceramics
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 18608
EUROPEAN STANDARD
NORME EUROPÉENNE
April 2022
EUROPÄISCHE NORM
ICS 81.060.30 Supersedes EN 13234:2006
English Version
Fine ceramics (advanced ceramics, advanced technical
ceramics) - Mechanical properties of ceramic composites
at ambient temperature in air atmospheric pressure -
Determination of the resistance to crack propagation by
notch sensitivity testing (ISO 18608:2017)
Céramiques techniques - Propriétés mécaniques des Hochleistungskeramik - Mechanische Eigenschaften
céramiques composites à température ambiante sous von keramischen Verbundwerkstoffen bei
pression atmosphérique - Détermination de la Umgebungstemperatur in Luft unter atmosphärischem
résistance à la propagation de fissure par un essai de Druck - Bestimmung der
sensibilité à l'entaille (ISO 18608:2017) Rissausbreitungsbeständigkeit durch die
Kerbempfindlichkeitsprüfung (ISO 18608:2017)
This European Standard was approved by CEN on 27 March 2022.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a 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 CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2022 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 18608:2022 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
The text of ISO 18608:2017 has been prepared by Technical Committee ISO/TC 206 "Fine ceramics” of
the International Organization for Standardization (ISO) and has been taken over as EN ISO 18608:2022
by Technical Committee CEN/TC 184 “Advanced technical ceramics” the secretariat of which is held by
DIN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by October 2022, and conflicting national standards shall
be withdrawn at the latest by October 2022.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 13234:2006.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO 18608:2017 has been approved by CEN as EN ISO 18608:2022 without any modification.

INTERNATIONAL ISO
STANDARD 18608
First edition
2017-03
Fine ceramics (advanced ceramics,
advanced technical ceramics) —
Mechanical properties of ceramic
composites at ambient temperature
in air atmospheric pressure —
Determination of the resistance
to crack propagation by notch
sensitivity testing
Céramiques techniques — Propriétés mécaniques des céramiques
composites à température ambiante sous pression atmosphérique
— Détermination de la résistance à la propagation de fissure par un
essai de sensibilité à l’entaille
Reference number
ISO 18608:2017(E)
©
ISO 2017
ISO 18608:2017(E)
© ISO 2017, Published in Switzerland
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ii © ISO 2017 – All rights reserved

ISO 18608:2017(E)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Significance and use . 2
6 Apparatus . 4
6.1 Test machine . 4
6.2 Load train. 4
6.2.1 General. 4
6.2.2 Grips . . . 4
6.2.3 Load train couplers . 4
6.3 Data recording system . 5
6.4 Micrometers . 5
6.5 Ligament size measuring device . 5
7 Specimens . 5
7.1 Un-notched test specimens . 5
7.2 Notched test specimens . 5
7.3 Notches . 6
8 Test specimen preparation . 7
8.1 Machining and preparation . 7
8.2 Number of test specimens . 7
9 Test procedure . 7
9.1 Test on reference specimen . 7
9.2 Test on notched specimen . 7
9.2.1 Displacement rate . 7
9.2.2 Measurement of test specimen dimensions . 7
9.2.3 Test technique . 7
9.2.4 Test validity . 8
10 Calculation of results . 8
10.1 Test specimen origin . 8
10.2 Tensile strength of un-notched specimen . 8
10.3 Tensile strength of the notched specimen . 8
10.4 Plotting of notch sensitivity diagram . 8
10.5 Calculation of equivalent fracture toughness for the different classes of behaviour . 9
10.5.1 Class A behaviour . 9
10.5.2 Class B behaviour . 9
10.5.3 Class C behaviour .10
11 Test report .10
Bibliography .11
ISO 18608:2017(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO’s adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following
URL: w w w . i s o .org/ iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 206, Fine ceramics.
iv © ISO 2017 – All rights reserved

INTERNATIONAL STANDARD ISO 18608:2017(E)
Fine ceramics (advanced ceramics, advanced technical
ceramics) — Mechanical properties of ceramic composites
at ambient temperature in air atmospheric pressure —
Determination of the resistance to crack propagation by
notch sensitivity testing
1 Scope
This document describes a method for the classification of ceramic matrix composite (CMC) materials
with respect to their sensitivity to crack propagation using tensile tests on notched specimens with
different notch depths. Two classes of ceramic matrix composite materials can be distinguished:
materials whose strength is sensitive to the presence of notches and materials whose strength is not
affected. For sensitive materials, this document defines a method for determining equivalent fracture
toughness.
The parameter, K , is defined as the fracture toughness of a homogeneous material which presents
eq
the same sensitivity to crack propagation as the ceramic matrix composite material which is being
considered. The definition of the K parameter offers the possibility to compare ceramic matrix
eq
composite materials with other materials with respect to sensitivity to crack propagation.
For notch insensitive materials, the concept of K does not apply.
eq
This document applies to all ceramic matrix composites with a continuous fibre reinforcement,
unidirectional (1 D), bidirectional (2 D), and tridirectional (x D, where 2 < x ≤ 3), loaded along one
principal axis of reinforcement.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 3611, Geometrical product specifications (GPS) — Dimensional measuring equipment: Micrometers for
external measurements — Design and metrological characteristics
ISO 7500-1, Metallic materials — Calibration and verification of static uniaxial test
...