SIST EN ISO 20504:2023

Fine ceramics (advanced ceramics, advanced technical ceramics) - Mechanical properties of ceramic composites at room temperature - Determination of compressive properties (ISO 20504:2022)

This document describes procedures for determination of the compressive behaviour of ceramic matrix composite materials with continuous fibre reinforcement at room temperature. This method applies to all ceramic matrix composites with a continuous fibre reinforcement, uni-directional (1D), bi-directional (2D) and tri-directional (xD, with 2 < x < 3), tested along one principal axis of reinforcement or off axis conditions. This method also applies to carbon-fibre-reinforced carbon matrix composites (also known as carbon/carbon or C/C). Two cases of testing are distinguished: compression between platens and compression using grips.

Hochleistungskeramik - Mechanische Eigenschaften von keramischen Verbundwerkstoffen bei Raumtemperatur - Bestimmung des Druckverhaltens (ISO 20504:2022)

Dieses Dokument beschreibt Verfahren zur Bestimmung des Druckverhaltens von endlosfaserverstärkten Verbundwerkstoffen mit keramischer Matrix bei Raumtemperatur. Diese Verfahren sind anwendbar für alle keramischen Verbundwerkstoffe mit keramischer Matrix, die endlosfaserverstärkt sind, mit unidirektionaler (1D), bidirektionaler (2D) und mehrdirektionaler (xD, mit 2 < x < 3) Endlosfaserverstärkung, die parallel zu einer der Hauptverstärkungsachsen oder außeraxial beansprucht werden. Diese Verfahren sind außerdem anwendbar für kohlenstofffaserverstärkte Verbundwerkstoffe mit Kohlenstoffmatrix (auch als Kohlenstoff/Kohlenstoff oder C/C bezeichnet). Es werden zwei Fälle von Prüfungen unterschieden: Druckbeanspruchung zwischen Platten und Druckbeanspruchung unter Verwendung von Einspanneinrichtungen.

Céramiques techniques - Propriétés mécaniques des composites à matrice céramiques à température ambiante - Méthode de détermination des propriétés en compression (ISO 20504:2022)

Le présent document décrit des procédures permettant de déterminer les caractéristiques en compression des matériaux composites à matrice céramique avec renfort de fibres continues à température ambiante. Il s’applique à tous les composites à matrice céramique avec renfort de fibres continues, unidirectionnel (1D), bidirectionnel (2D) et tridirectionnel (xD, avec 2 < x < 3), sollicités suivant un axe principal de renfort ou dans des conditions hors axe. Il peut également s’appliquer aux composites à matrice de carbone avec renfort de fibres de carbone (également connus en tant que carbone/carbone ou C/C). Deux cas de compression sont distingués: la compression entre plateaux et la compression entre mors.

Fina keramika (sodobna keramika, sodobna tehnična keramika) - Mehanske lastnosti keramičnih kompozitov pri sobni temperaturi - Določanje tlačnih lastnosti (ISO 20504:2022)

Ta dokument opisuje postopke za določanje vedenja keramičnih matričnih kompozitnih materialov z neprekinjeno ojačitvijo vlaken pri stiskanju pri sobni temperaturi. Ta metoda se uporablja za vse keramične matrične kompozite z neprekinjeno ojačitvijo vlaken, enosmerno (1D), dvosmerno (2D) in trismerno (xD, pri čemer je 2 < x ≤ 3), preskušene vzdolž ene glavne osi ojačitve ali v pogojih zunaj osi. Ta metoda se uporablja tudi za karbonske matrične kompozite s karbonskimi vlakni (imenovane tudi karbon/karbon ali C/C). Razlikujemo med dvema primeroma preskušanja: stiskanje med stiskalnimi valji in stiskanje z ročaji.

General Information

• Status: Published
• Public Enquiry End Date: 25-Oct-2022
• Publication Date: 23-Jan-2023
• ICS: 81.060.30 - Advanced ceramics
• Technical Committee: I13 - Imaginarni 13
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 04-Jan-2023
• Due Date: 11-Mar-2023
• Completion Date: 24-Jan-2023
• Ref Project: EN ISO 20504:2022 - Fine ceramics (advanced ceramics, advanced technical ceramics) - Mechanical properties of ceramic composites at room temperature - Determination of compressive properties (ISO 20504:2022)

Relations

• Replaces: SIST EN ISO 20504:2019 - Fine ceramics (advanced ceramics, advanced technical ceramics) - Mechanical properties of ceramic composites at room temperature - Determination of compressive properties (ISO 20504:2019)
• Effective Date: 21-Dec-2022
• Revised: SIST EN ISO 20504:2019 - Fine ceramics (advanced ceramics, advanced technical ceramics) - Mechanical properties of ceramic composites at room temperature - Determination of compressive properties (ISO 20504:2019)
• Effective Date: 29-Dec-2021

Overview

EN ISO 20504:2022 specifies a standardized method for determining the compressive properties of ceramic matrix composites (CMCs) at room temperature. It covers advanced and technical fine ceramics reinforced with continuous fibres - uni‑directional (1D), bi‑directional (2D) and tri‑directional (xD) - and also applies to carbon‑fibre‑reinforced carbon matrix composites (C/C). The standard distinguishes two test setups: compression between platens and compression using grips, and it defines required apparatus, specimen preparation, test procedures, data acquisition and result calculations.

Key topics and technical requirements

• Scope and applicability: Tests along a principal reinforcement axis or off‑axis conditions for continuous‑fibre ceramic matrix composites.
• Test apparatus: Requirements for test machines, load trains, platens/grips and dimensional measuring devices.
• Strain measurement: Use of extensometers and strain gauges; calibration and alignment considerations.
• Specimen geometry and preparation: Machining, calibrated length, initial gauge length and cross‑section measurement to avoid artefacts such as buckling.
• Test procedure: Controlled test rate, mounting techniques, measurement of dimensions, and test validity checks.
• Data and calculations: Determination of compressive strength, strain at maximum compressive force, proportionality ratio / pseudo‑elastic modulus (elastic modulus) and reporting requirements.
• Quality and traceability: Reference to calibration and verification standards for force and extensometry to ensure reliable, comparable results.

Practical applications and users

EN ISO 20504:2022 is essential for organizations working with advanced ceramics and ceramic composites where compressive performance is critical. Typical uses include:

• Materials R&D: Characterizing new CMC architectures and matrix/fibre systems.
• Design verification: Providing input data for structural analysis and component design in aerospace, defense, automotive and energy applications.
• Quality control and supplier qualification: Routine batch testing, acceptance testing and comparative evaluation of incoming materials.
• Certification and regulatory compliance: Demonstrating mechanical performance under standardized conditions for procurement or certification programs.
  Primary users: materials engineers, test laboratory technicians, product qualification teams, standards committees and ceramic manufacturers.

Related standards

Standards referenced by EN ISO 20504:2022 for calibration and measurement practices include:

• ISO 7500‑1 (calibration of force measuring systems)
• ISO 9513 (calibration of extensometer systems)
• ISO 3611 (dimensional measuring equipment - micrometers)
• ISO 17161 (degree of misalignment in uniaxial tests)
• ISO 14744 (acceptance inspection of electron beam welding machines)

Using EN ISO 20504:2022 ensures consistent, repeatable compression testing of ceramic composites and delivers comparable mechanical property data for engineering, procurement and research purposes.

Standards Content (Sample)

SLOVENSKI STANDARD
01-marec-2023
Nadomešča:
SIST EN ISO 20504:2019
Fina keramika (sodobna keramika, sodobna tehnična keramika) - Mehanske
lastnosti keramičnih kompozitov pri sobni temperaturi - Določanje tlačnih lastnosti
(ISO 20504:2022)
Fine ceramics (advanced ceramics, advanced technical ceramics) - Mechanical
properties of ceramic composites at room temperature - Determination of compressive
properties (ISO 20504:2022)
Hochleistungskeramik - Mechanische Eigenschaften von keramischen
Verbundwerkstoffen bei Raumtemperatur - Bestimmung des Druckverhaltens (ISO
20504:2022)
Céramiques techniques - Propriétés mécaniques des composites à matrice céramiques
à température ambiante - Méthode de détermination des propriétés en compression
(ISO 20504:2022)
Ta slovenski standard je istoveten z: EN ISO 20504:2022
ICS:
81.060.30 Sodobna keramika Advanced ceramics
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 20504
EUROPEAN STANDARD
NORME EUROPÉENNE
December 2022
EUROPÄISCHE NORM
ICS 81.060.30 Supersedes EN ISO 20504:2019
English Version
Fine ceramics (advanced ceramics, advanced technical
ceramics) - Mechanical properties of ceramic composites
at room temperature - Determination of compressive
properties (ISO 20504:2022)
Céramiques techniques - Propriétés mécaniques des Hochleistungskeramik - Mechanische Eigenschaften
composites à matrice céramiques à température von keramischen Verbundwerkstoffen bei
ambiante - Méthode de détermination des propriétés Raumtemperatur - Bestimmung des Druckverhaltens
en compression (ISO 20504:2022) (ISO 20504:2022)
This European Standard was approved by CEN on 28 November 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, Türkiye 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 20504:2022 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 20504:2022) has been prepared by Technical Committee ISO/TC 206 "Fine
ceramics" in collaboration with 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 June 2023, and conflicting national standards shall be
withdrawn at the latest by June 2023.
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 ISO 20504:2019.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. 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, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 20504:2022 has been approved by CEN as EN ISO 20504:2022 without any modification.

INTERNATIONAL ISO
STANDARD 20504
Third edition
2022-12
Fine ceramics (advanced ceramics,
advanced technical ceramics) —
Mechanical properties of ceramic
composites at room temperature
— Determination of compressive
properties
Céramiques techniques — Propriétés mécaniques des composites
à matrice céramiques à température ambiante — Méthode de
détermination des propriétés en compression
Reference number
ISO 20504:2022(E)
ISO 20504:2022(E)
© ISO 2022
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
ISO 20504:2022(E)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 3
5 Apparatus . 3
5.1 Test machine . 3
5.2 Load train . 3
5.3 Strain measurement . 4
5.3.1 General . 4
5.3.2 Strain gauges. 4
5.3.3 Extensometry . 4
5.4 Data recording system . 4
5.5 Dimension-measuring devices . 4
6 Test specimens . 5
6.1 General . 5
6.2 Compression between platens . . 5
6.3 Test specimen used with grips . 7
7 Test specimen preparation .10
7.1 Machining and preparation . 10
7.2 Number of test specimens . 10
8 Test procedure .10
8.1 Test mode and rate . 10
8.2 Measurement of test specimen dimensions . 10
8.3 Buckling . 10
8.4 Testing technique . 11
8.4.1 Test specimen mounting . 11
8.4.2 Extensometers. 11
8.4.3 Measurements . 11
8.5 Test validity . 11
9 Calculation of results .11
9.1 Test specimen origin . 11
9.2 Compressive strength . 12
9.3 Strain at maximum compressive force .12
9.4 Proportionality ratio or pseudo-elastic modulus, elastic modulus .12
10 Test report .13
Annex A (informative) Illustration of elastic modulus .15
Bibliography .17
iii
ISO 20504:2022(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 of 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
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 206, Fine ceramics, in collaboration
with the European Committee for Standardization (CEN) Technical Committee CEN/TC 184, Advanced
technical ceramics, in accordance with the Agreement on technical cooperation between ISO and CEN
(Vienna Agreement).
This third edition cancels and replaces the second edition (ISO 20504:2019), of which it constitutes a
minor revision. The changes are as follows:
— notation of 3.3 and 3.4 harmonized and replaced throughout the document;
— duplicated text removed from the definition in 3.6;
— minor editorial changes.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
INTERNATIONAL STANDARD ISO 20504:2022(E)
Fine ceramics (advanced ceramics, advanced technical
ceramics) — Mechanical properties of ceramic composites
at room temperature — Determination of compressive
properties
1 Scope
This document describes procedures for determination of the compressive behaviour of ceramic
matrix composite materials with continuous fibre reinforcement at room temperature. This method
applies to all ceramic matrix composites with a continuous fibre reinforcement, uni-directional (1D), bi-
directional (2D) and tri-directional (xD, with 2 < x < 3), tested along one principal axis of reinforcement
or off axis conditions. This method also applies to carbon-fibre-reinforced carbon matrix composites
(also known as carbon/carbon or C/C). Two cases of testing are distinguished: compression between
platens and compression using grips.
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 testing machines — Part 1:
Tension/compression testing machines — Calibration and verification of the force-measuring system
ISO 9513, Metallic materials — Calibration of extensometer systems used in uniaxial testing
ISO 14744, Welding — Acceptance inspection of electron beam welding machines
ISO 17161, Fine ceramics (advanced ceramics, advanced technical ceramics) — Ceramic composites —
Determination of the degree of misalignment in uniaxial mechanical tests
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
calibrated length
part of the test specimen which has uniform and minimum cross-sectional area
3.2
initial gauge length
L
o
initial distance between reference points on the test specimen in the calibrated length before initiation
of the test
ISO 20504:2022(E)
3.3
initial cross-sectional area
S
o
initial area of specimen cross-section in the calibration length
3.4
longitudinal deformation
A
decrease of the initial gauge length under compressive force
Note 1 to entry: The longitudinal deformation corresponding to the maximum force is denoted as A .
c,m
3.5
compressive strain
ε
relative decrease of the gauge length defined as the ratio A/L
o
Note 1 to entry: The compressive strain corresponding to the maximum force is denoted as ε .
c,m
3.6
compressive force
F
c
uniaxial force carried by the test specimen at any time during the test
3.7
maximum compressive force
F
c,m
greatest uniaxial compressive force applied to the test specimen when tested to failure
3.8
compressive stress
σ
compressive force supported by the test specimen at any time in the test divided by the initial cross-
sectional area such that σ = F /S
c o
3.9
compressive strength
S
c,m
greatest compressive stress applied to a test specimen when tested to failure
3.10
proportionality ratio
pseudo-elastic modulus
E
p
slope of the linear region of the stress-strain curve, if any
Note 1 to entry: Examination of the stress-strain curves for ceramic matrix composites allows definition of the
following cases:
— Material with a linear region in the stress-strain curve.
For ceramic matrix composites that have a mechanical behaviour characterised by a linear region, the
proportionality ratio E is defined using Formula (1).
p
σσ−
E ()σσ, = (1)
p 12
εε−
where (ε , σ ) and (ε , σ ) lie near the lower and the upper limits of the linear region of the stress-strain curve
1 1 2 2
(see Annex A, Figures A.1 and A.2).
— Material with nonlinear region in the stress-strain curve. In this case only, stress-strain couples can be
determined at specified stresses or specified strains.
ISO 20504:2022(E)
3.11
elastic modulus
E
proportionality ratio or pseudo-elastic modulus, in the special case where the linearity starts near the
origin
Note 1 to entry: See Figure A.2.
4 Principle
A test specimen of specified dimensions is loaded in compression. The compression test is usually
performed at a constant cross-head displacement rate or at a constant deformation rate.
Constant force rate is only allowed in the case of linear stress-strain behaviour up to failure.
For crosshead displacement tests, a constant rate is recommended when the test is conducted to failure.
The force and longitudinal deformation are measured and recorded simultaneously.
5 Apparatus
5.1 Test machine
Th
...