EN ISO 18610:2021

SLOVENSKI STANDARD
01-marec-2021
Fina keramika (sodobna keramika, sodobna tehnična keramika) - Mehanske
lastnosti keramičnih kompozitov pri temperaturi okolice in pri zračnem tlaku -
Ugotavljanje elastičnih lastnosti z ultrazvokom (ISO 18610:2016)
Fine ceramics (advanced ceramics, advanced technical ceramics) - Mechanical
properties of ceramic composites at ambient temperature in air atmospheric pressure -
Determination of elastic properties by ultrasonic technique (ISO 18610:2016)
Hochleistungskeramik - Mechanische Eigenschaften von keramischen
Verbundwerkstoffen bei Raumtemperatur - Bestimmung der elastischen Eigenschaften
durch eine Ultraschallmethode (ISO 18610:2016)
Céramiques techniques (céramiques avancées, céramiques techniques avancées) -
Propriétés mécaniques des céramiques composites à température ambiante sous air à
pression atmosphérique - Détermination des propriétés élastiques par méthode
ultrasonore (ISO 18610:2016)
Ta slovenski standard je istoveten z: EN ISO 18610:2021
ICS:
81.060.30 Sodobna keramika Advanced ceramics
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 18610
EUROPEAN STANDARD
NORME EUROPÉENNE
January 2021
EUROPÄISCHE NORM
ICS 81.060.30
English Version
Fine ceramics (advanced ceramics, advanced technical
ceramics) - Mechanical properties of ceramic composites
at ambient temperature in air atmospheric pressure -
Determination of elastic properties by ultrasonic
technique (ISO 18610:2016)
Céramiques techniques (céramiques avancées, Hochleistungskeramik - Mechanische Eigenschaften
céramiques techniques avancées) - Propriétés von keramischen Verbundwerkstoffen bei
mécaniques des céramiques composites à température Raumtemperatur - Bestimmung der elastischen
ambiante sous air à pression atmosphérique - Eigenschaften durch eine Ultraschallmethode (ISO
Détermination des propriétés élastiques par méthode 18610:2016)
ultrasonore (ISO 18610:2016)
This European Standard was approved by CEN on 20 December 2020.

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
© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 18610:2021 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
The text of ISO 18610:2016 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 18610:2021
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 July 2021, and conflicting national standards shall be
withdrawn at the latest by July 2021.
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.
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 18610:2016 has been approved by CEN as EN ISO 18610:2021 without any modification.

INTERNATIONAL ISO
STANDARD 18610
First edition
2016-09-15
Fine ceramics (advanced ceramics,
advanced technical ceramics) —
Mechanical properties of ceramic
composites at ambient temperature
in air atmospheric pressure —
Determination of elastic properties by
ultrasonic technique
Céramiques techniques (céramiques avancées, céramiques techniques
avancées) — Propriétés mécaniques des céramiques composites
à température ambiante sous air à pression atmosphérique —
Détermination des propriétés élastiques par méthode ultrasonore
Reference number
ISO 18610:2016(E)
©
ISO 2016
ISO 18610:2016(E)
© ISO 2016, Published in Switzerland
All rights reserved. Unless otherwise specified, 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
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Tel. +41 22 749 01 11
Fax +41 22 749 09 47
copyright@iso.org
www.iso.org
ii © ISO 2016 – All rights reserved

ISO 18610:2016(E)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 5
5 Significance and use . 6
6 Test equipment. 7
6.1 Immersion tank with temperature measurement device . 7
6.2 Holder of the probes and test object . 7
6.3 Probes . 7
6.4 Pulse generator . 7
6.5 Signal display and recording system . 7
7 Test object . 7
8 Test object preparation . 8
9 Test procedure . 8
9.1 Choice of frequency . 8
9.2 Establishment of the test temperature . 9
9.3 Reference test without test object . 9
9.4 Measurement with the test object . 9
9.4.1 Determination of the bulk density and thickness . 9
9.4.2 Mounting of the test object . 9
9.4.3 Acquisition of different angles of incidence . 9
10 Calculation .10
10.1 Delay .10
10.2 Calculation of the propagation velocities .10
10.3 Calculation of the refracted angle, θ .10
r
10.4 Identification of the elastic constants, C .10
ij
10.4.1 Basic considerations .10
10.4.2 Calculation of C .12
10.4.3 Calculation of C , C and C .12
22 23 44
10.4.4 Calculation of C , C and C .12
11 13 55
10.4.5 Calculation of C and C .12
12 66
10.5 Polar plots of the velocity curves .13
10.6 Calculation of the quadratic deviation and the confidence interval .14
10.7 Calculation of the engineering constants .14
11 Test validity .15
11.1 Measurements .15
11.2 Criterion of validity for the reliability of the C components .15
ij
12 Test report .15
Annex A (informative) Example of a presentation of the results for a material with
orthotropic symmetry .17
Bibliography .19
ISO 18610:2016(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 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.
The committee responsible for this document is ISO/TC 206, Fine ceramics.
iv © ISO 2016 – All rights reserved

INTERNATIONAL STANDARD ISO 18610:2016(E)
Fine ceramics (advanced ceramics, advanced technical
ceramics) — Mechanical properties of ceramic composites
at ambient temperature in air atmospheric pressure
— Determination of elastic properties by ultrasonic
technique
1 Scope
This document specifies an ultrasonic method to determine the components of the elasticity tensor of
ceramic matrix composite materials at room temperature. Young’s moduli shear moduli and Poisson
coefficients, can be determined from the components of the elasticity tensor.
This document applies to ceramic matrix composites with a continuous fibre reinforcement:
unidirectional (1D), bidirectional (2D), and tridirectional (×D, with 2 < × ≤ 3) which have at least
orthotropic symmetry, and whose material symmetry axes are known.
This method is applicable only when the ultrasonic wavelength used is larger than the thickness of
the representative elementary volume, thus imposing an upper limit to the frequency range of the
transducers used.
NOTE Properties obtained by this method might not be comparable with moduli obtained by ISO 15733,
ISO 20504 and EN 12289.
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/IEC 17025, General requirements for the competence of testing and calibration laboratories
EN 1389, Advanced technical ceramics — Ceramic composites — Physical properties — Determination of
density and apparent porosity
3 Terms and definitions
For the purposes of this document, the terms and definitions given in CEN/TR 13233 and the
following apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at http://www.iso.org/obp
ISO 18610:2016(E)
3.1
stress-strain relations for orthotropic material
elastic anisotropic behaviour of a solid homogeneous body described by the elasticity tensor of fourth
order C , represented in the contracted notation by a symmetrical square matrix (6 × 6)
ijkl
Note 1 to entry: If the material has at least orthotropic symmetry, its elastic behaviour is fully characterized
by nine independent stiffness components C , of the stiffness matrix (C ), which relates stresses to strains, or
ij ij
equivalently by nine independent compliance components S of the compliance matrix (S ), which relates strains
ij ij
to stresses. The stiffness and compliance matrices are the inverse of each other.
If the reference coordinate system is chosen along the axes of symmetry, the stiffness matrix C and the
ij
compliance matrix S can be written as follows:
ij
     
σ C C C 00 0 ε
1 11 12 13 1
     
σ CC C 000 εε
     
2 12 22 23 2
     
σ C CC 000 ε
3 113 23 33 3
     
=
σ 000 C 00 ε
     
4 44 4
     
σ 000 00C ε
5 55 5
     
σ  000 00 C  ε 
6 66 6
     
     
ε SS S 00 0 σ
1 11 12 13 1
     
ε SS S 000 σσ
  
2 12 22 23  2
     
ε S SS 000 σ
3 113 23 33 3
     
=
ε 000 S 00 σ
     
4 44 4
     
ε 000 00S σ
5 55 5
     
ε  000 00 S  σ 
6 66 6
     
Note 2 to entry: For symmetries of higher level than the orthotropic symmetry, the C and S matrices have the
ij ij
same form as here above. Only the number of independent components reduces.
3.2
engineering constants
compliance matrix components of an orthotropic material which are in terms of engineering constants:
 
−ν −ν
121 31
00 0
 
EE
E
11 33
 
−ν −ν
12 1 32
 00 0 
EE
E
11 33
 
−ν
−νν
 
13 23 1
00 0
 E 
 
E E
S =
ij 11 33
 
 
00 0 00
 
G
 
00 00 0
 
G
 
00 00 0
 
G
 12
where
E , E and E are the elastic moduli in directions 1, 2 and 3, respectively;
11 22 33
G , G and G are the shear moduli in the corresponding planes;
12 13 23
ν , ν , ν are the respective Poisson coefficients.
12 13 23
2 © ISO 2016 – All rights reserved

ISO 18610:2016(E)
3.3
angle of incidence
θ
i
angle between the direction 3 normal to the test specimen front face and the direction n of the
i
incident wave
Note 1 to entry: See Figures 1 and 2.
3.4
refracted angle
θ
r
angle between the direction 3 normal to the test specimen front face and the direction n of propagation
of the wave inside the test specimen
Note 1 to entry: See Figures 1 and 2.
3.5
azimuthal angle
ψ
angle between the plane of incidence (3, n ) and plane (2, 3) where n corresponds to the vector oriented
i i
along the incident plane wave and direction 2 corresponds to one of the axes of symmetry of the
material
Note 1 to entry: See Figure 1.
r
n
Figure 1 — Definition of angles
h
ISO 18610:2016(E)
i
r
n
n
i
i
Figure 2 — Propagation in the plane of incidence
3.6
first critical angle
θ
c
angle of incidence θ that provides an angle of refraction of 90 degrees of the quasi longitudinal wave angle
i
3.7
unit vector
n
vector of length 1 oriented along the propagation direction of the incident plane wave inside the
specimen, with its components n (k = 1, 2, 3):
k
n =sinsθψin
1 r
n =sincθψos
2 r
n =cosθ
3 r
Note 1 to entry: See Figures 1 and 2.
3.8
propagation velocity
V(n)
phase velocity of a plane wave inside the specimen in dependence on unit vector n (i.e. in dependence
on ψ and θ )
r
Note 1 to entry: V is the propagation velocity in the coupling fluid.
o
3.9
delay
δt(n)
difference between the time-of-flight of the wave when the test specimen is in place and the time-of-
flight of the wave in the coupling fluid with the test specimen removed under the same configuration of
the probes in dependence on unit vector n
3.10
bulk density
ρ
ratio of the mass of the material without porosity to its total volume including porosity
4 © ISO 2016 – All rights reserved

ISO 18610:2016(E)
4 Principle
The determination of the elastic properties consists of calculating the coefficients of the propagation
equation of an elastic plane wave, from a set of properly chosen velocity measurements along known
directions.
A thin specimen with plane parallel faces is immersed in an acoustically coupling fluid (e.g. water),
see Figure 3. The specimen is placed between a transmitter (T) and a receiver (R), which are rigidly
connected to each other and have two rotational degrees of freedom. Using appropriate signal
processing, the propagation velocities of each wave in the specimen are calculated.
θ i
Key
1 rotation drive
2 test object
3 pulse generator
4 digital oscilloscope
5 micro-computer
Figure 3 — Ultrasonic test assembly
Depending on the angle of incidence, the wave created by the pulse sent by the transmitter T is refracted
within the material in one (a quasi longitudinal wave QL, or a quasi transverse wave QT), two (QL+ QT or
two quasi transverse waves QT , QT ) or three bulk waves (QL+ QT +QT ) that propagate in the solid at
1 2 1 2
different velocities and in different directions.
The receiver R collects one, two or three pulses, corresponding to each of these waves.
The difference between the time-of-flight of each of the waves and the time-of-flight of the transmitted
pulse in the coupling fluid without the test object is measured. The evaluation procedure is based on
the measurement of the time-of-flight of the quasi-longitudinal and one or both quasi-transverse waves,
and is only valid when the QL and the QT waves are appropriately separated (see Figure 4).
ISO 18610:2016(E)
05 10 15 20 25
θ
Key Key
Y  amplitude Y  amplitude
X  angle of incidence X  time
NOTE  Both QL and QT waves are present and can
be distinguished in the positive domain but are
slightly overlapping in the negative domain.
a) Amplitude of the QL and QT waves as a b) Temporal waveform of the QL and QT waves
function of the angle of incidence with at an angle of incidence, θ , close to the critical
i
overlapping in the region of θ angle, θ
c c
Figure 4 — Example of partial overlapping of QL and QT waves at an angle of incidence θ
i
From the propagation velocities, the components of the elasticity tensor are obtained through a least
square regression analysis which minimizes the residuals of the wave propagation equations.
Young’s moduli, shear moduli and Poisson coefficients are determined from these components.
5 Significance and use
Only two constants (Lamés coefficients, Young’s modulus and Poisson coefficient, Young’s and shear
moduli, longitudinal and transverse wave velocities) are sufficient in order to fully describe the
elastic behaviour of an isotropic solid body. When anisotropy, which is a specific feature of composite
materials, shall be taken into account, the use of an elasticity tensor with a larger number of independent
coefficients is needed. While conventional mechanical methods allow only a partial identification of
the elasticity of anisotropic bodies, ultrasonic techniques allow a more exhaustive evaluation of the
elastic properties of these materials, particularly transverse elastic moduli and shear moduli for thin
specimens.
Successful application of the method depends critically on an appropriate selection of the central
frequency of the transducers. Frequency shall be sufficiently low for the measurement to be
representative of the elementary volume response, but at the same time high enough to achieve a
separation between the QL and the QT waves.
The determination of elastic properties by the ultrasonic technique described here is based on a non-
destructive dynamic measurement of wave propagation velocities. The determination of the values of
Young’s moduli, shear moduli and Poisson ratios need a single specimen.
6 © ISO 2016 – All rights reserved

ISO 18610:2016(E)
6 Test equipment
6.1 Immersion tank with temperature measurement device
The temperature of the coupling fluid in the immersion tank should stay constant within ±0,5 °C for the
full duration of the test.
The temperature measurement device shall be capable of measuring the temperature to within 0,5 °C.
This requirement is imposed because the wave propagation velocity in the coupling fluid is temperature
sensitive.
6.2 Holder of the probes and test object
The holder of the ultrasonic probes or the holder of the test object shall allow a rotation to cover the
range of angles of incidence θ between 0° and 90°. Additionally, it shall allow for discrete settings of the
i
azimuthal angle ± of 0°, 45° and 90°. The accuracy in the measurement of the angles θ
...