oSIST prEN ISO 19634:2025
(Main)Fine ceramics (advanced ceramics, advanced technical ceramics) - Ceramic composites - Notations and symbols (ISO/DIS 19634:2024)
Fine ceramics (advanced ceramics, advanced technical ceramics) - Ceramic composites - Notations and symbols (ISO/DIS 19634:2024)
ISO 19634:2017 defines the symbols to be used to represent physical, mechanical and thermal characteristics, as determined by methods described in relevant ISO publications, for ceramic matrix composites. It is aimed at avoiding confusion in reporting measurements and characteristics of products.
Where possible, the definitions are in accordance with the relevant parts of ISO 80000. In addition, the symbols used in undertaking measurements of these characteristics are also defined.
Hochleistungskeramik - Keramische Verbundwerkstoffe - Benennungen und Formelzeichen (ISO/DIS 19634:2024)
Céramiques techniques - Céramiques composites - Notations et symboles (ISO/DIS 19634:2024)
L'ISO 19634 :2017 définit les symboles à utiliser pour représenter les caractéristiques physiques, mécaniques et thermiques, telles que déterminées par les méthodes décrites dans les publications ISO concernées, pour les composites à matrice céramique. Il vise à éviter toute confusion dans les rapports de mesures et de caractéristiques des produits.
Dans toute la mesure du possible, les définitions sont conformes aux parties pertinentes de l'ISO 80000. En outre, les symboles utilisés pour la mesure de ces caractéristiques sont également définis.
Fina keramika (sodobna keramika, sodobna tehnična keramika) - Keramični kompoziti - Oznake in simboli (ISO/DIS 19634:2024)
General Information
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Standards Content (Sample)
SLOVENSKI STANDARD
01-marec-2025
Fina keramika (sodobna keramika, sodobna tehnična keramika) - Keramični
kompoziti - Oznake in simboli (ISO/DIS 19634:2024)
Fine ceramics (advanced ceramics, advanced technical ceramics) - Ceramic composites
- Notations and symbols (ISO/DIS 19634:2024)
Hochleistungskeramik - Keramische Verbundwerkstoffe - Benennungen und
Formelzeichen (ISO/DIS 19634:2024)
Céramiques techniques - Céramiques composites - Notations et symboles (ISO/DIS
19634:2024)
Ta slovenski standard je istoveten z: prEN ISO 19634
ICS:
01.075 Simboli za znake Character symbols
81.060.30 Sodobna keramika Advanced ceramics
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
DRAFT
International
Standard
ISO/DIS 19634
ISO/TC 206
Fine ceramics (advanced ceramics,
Secretariat: JISC
advanced technical ceramics) —
Voting begins on:
Ceramic composites — Notations
2024-12-30
and symbols
Voting terminates on:
2025-03-24
Céramiques techniques — Céramiques composites — Notations et
symboles
ICS: 81.060.30
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
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POTENTIAL TO BECOME STANDARDS TO
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RECIPIENTS OF THIS DRAFT ARE INVITED
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RIGHTS OF WHICH THEY ARE AWARE AND TO
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Reference number
ISO/DIS 19634:2024(en)
DRAFT
ISO/DIS 19634:2024(en)
International
Standard
ISO/DIS 19634
ISO/TC 206
Fine ceramics (advanced ceramics,
Secretariat: JISC
advanced technical ceramics) —
Voting begins on:
Ceramic composites — Notations
and symbols
Voting terminates on:
Céramiques techniques — Céramiques composites — Notations et
symboles
ICS: 81.060.30
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
© ISO 2024
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
BE CONSIDERED IN THE LIGHT OF THEIR
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Published in Switzerland Reference number
ISO/DIS 19634:2024(en)
ii
ISO/DIS 19634:2024(en)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols . 4
5 Significance and use .13
5.1 Significance . . . 13
5.2 Use . 13
Bibliography . 14
iii
ISO/DIS 19634:2024(en)
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:
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 206, Fine ceramics.
iv
DRAFT International Standard ISO/DIS 19634:2024(en)
Fine ceramics (advanced ceramics, advanced technical
ceramics) — Ceramic composites — Notations and symbols
1 Scope
This document defines the symbols to be used to represent physical, mechanical and thermal characteristics,
as determined by methods described in relevant ISO publications, for ceramic matrix composites. It is aimed
at avoiding confusion in reporting measurements and characteristics of products.
Where possible, the definitions are in accordance with the relevant parts of ISO 80000. In addition, the
symbols used in undertaking measurements of these characteristics are also defined.
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 80000-4, Quantities and units — Part 4: Mechanics
ISO 80000-5, Quantities and units — Part 5: Thermodynamics
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 80000-4 and ISO 80000-5 and the
following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at https:// www .electropedia .org/
— ISO Online browsing platform: available at https:// www .iso .org/ obp
3.1
ceramic matrix composite
ceramic, carbon or glass matrix containing reinforcement distributed in one or more spatial directions
Note 1 to entry: Composites with continuous reinforcements constitute a specific class of these materials. Several
subclasses of ceramic matrix composites with continuous reinforcements can be distinguished.
3.2
nomenclature
The symbol F/I/M applies usually to ceramic matrix composites:
— F indicates the chemical nature of fibrous reinforcement: C stands for carbon, SiC for silicon carbide,
Al O for alumina, etc.
2 3
— I indicates the chemical nature of fibre/matrix interphase: C stands for carbon, BN for boron nitride,
LaPO for monazite, etc.
— M indicates the chemical nature of matrix: C for carbon, SiC for silicon carbide, Al O for alumina.
2 3
EXAMPLE 1 A ceramic matrix composite composed of a silicon carbide fibre, a carbon interphase and a silicon
carbide matrix is denoted by SiC/C/SiC.
ISO/DIS 19634:2024(en)
Note 1 to entry: More complex symbols can be used to describe the constituents with a greater degree of precision.
EXAMPLE 2 For a composite composed of a carbon fibre, a multi-layered interphase of four alternate layers of
carbon and silicon carbide, and a silicon carbide matrix, the symbol is: C /[C/SiC] /SiC .
f 4 m
3.3
unidirectional ceramic matrix composite
1D material
ceramic matrix composite (3.1), the reinforcement of which is distributed in one single direction
Note 1 to entry: See Figure 1.
Key
1 direction of reinforcement
2 direction of the greater transverse dimension (width), perpendicular to direction 1
3 direction of the smaller transverse dimension (thickness), perpendicular to direction 1
NOTE When the width and the thickness are equal, then directions 2 and 3 are equivalent and can be chosen freely.
Figure 1 — Schematic diagram of a 1D material
3.4
in-plane reinforced ceramic matrix composite
2D material
ceramic matrix composite (3.1), where the reinforcements are placed along at least two directions in a single plane
Note 1 to entry: See Figure 2.
ISO/DIS 19634:2024(en)
Key
1 direction of the greater fraction of reinforcement
2 direction perpendicular to direction 1 in the plane of reinforcement (not necessarily a direction of reinforcement)
3 direction perpendicular to the plane of reinforcement
NOTE Strictly more than one direction of fibrous reinforcement, all contained within one plane [in the present case,
three directions of reinforcement in plane (1,2)].
When several directions have an equal fraction of reinforcement, it shall be stated which direction is chosen
as direction 1 in relation to the reinforcement structure (for example, orthogonal reinforced fabric: warp in
direction 1, weft in direction 2).
Figure 2 — Schematic diagram of a 2D material
3.5
multidirectional ceramic matrix composite
xD (2 < × ≤3) material
ceramic matrix composite (3.1), where the reinforcement is spatially distributed in at least three directions
not in a single plane
Note 1 to entry: See Figures 3 and 4.
Figure 3 — Schematic diagram of a xD (2 < × ≤ 3) material
ISO/DIS 19634:2024(en)
Key
1 direction of the greater fraction of reinforcement
2 direction perpendicular to direction 1
3 direction perpendicular to the plane containing directions 1 and 2
When several directions have equal fraction of reinforcement, it shall be stated which direction is chosen as direction 1, in
relation to the reinforcement structure. When it is possible to define a plane of reinforcement, direction 2 will be chosen
in this plane perpendicular to direction 1 (direction 2 is not necessarily a direction of reinforcement), and direction 3 will
be perpendicular to the plane containing directions 1 and 2. When it is not possible to define a plane of reinforcement,
direction 2 is chosen arbitrarily, but perpendicular to direction 1 and shall be clearly identified.
Figure 4 — Schematic diagram of a 3D material
4 Symbols
The symbols used for the various mechanical and thermal quantities are given in Tables 1 to 4.
ISO/DIS 19634:2024(en)
Table 1 — Symbols related to physical quantities
Quantity Symbol Definition Unit Remark
Density ρ Ratio of the mass of a body to its volume kg/m
Apparent density ρ Ratio of the mass of the body to its total vol- kg/m
a
ume
Bulk density ρ Ratio of the mass of the dry material of a po- kg/m Bulk volume = sum of volumes of solid ma-
b
rous body to its volume terial, open pores and closed pores
Ratio of the mass of a multifilament to
...
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