prEN ISO 19629

Fine ceramics (advanced ceramics, advanced technical ceramics) - Thermophysical properties of ceramic composites - Determination of unidimensional thermal diffusivity by flash method (ISO 19629:2018)

This document describes the flash method for the determination of thermal diffusivity of ceramic matrix composites with continuous fibre reinforcement.
In order to conform with the unidimensional heat transfer hypothesis, the experimental conditions are defined such that the material behaves in a homogeneous manner. This involves performing tests in one symmetry axis of the composite.
The method is applicable to materials which are physically and chemically stable during the measurement, and covers the range of temperature from 100 K to 2 800 K. It is suitable for the measurement of thermal diffusivity values in the range 10−4 m2∙s−1 to 10−7 m2∙s−1.

Hochleistungskeramik - Thermophysikalische Eigenschaften keramischer Verbundwerkstoffe - Bestimmung der Temperaturleitfähigkeit (ISO 19629:2018)

Céramiques techniques - Propriétés thermophysiques des composites céramiques - Détermination de la diffusivité thermique unidimensionnelle par la méthode flash (ISO 19629:2018)

Fina keramika (sodobna keramika, sodobna tehnična keramika) - Termofizikalne lastnosti keramičnih kompozitov - Ugotavljanje enodimenzionalne toplotne difuzivnosti z bliskovno metodo (ISO 19629:2018)

General Information

• Status: Not Published
• ICS: 81.060.30 - Advanced ceramics
• Technical Committee: CEN/TC 184 - Advanced technical ceramics
• Drafting Committee: CEN/TC 184 - Advanced technical ceramics
• Current Stage: 4060 - Closure of enquiry - Enquiry
• Due Date: 26-Feb-2022
• Completion Date: 26-Feb-2022
• Ref Project: oSIST prEN ISO 19629:2022 - Fine ceramics (advanced ceramics, advanced technical ceramics) - Thermophysical properties of ceramic composites - Determination of unidimensional thermal diffusivity by flash method (ISO 19629:2018)

Standards Content (sample)

SLOVENSKI STANDARD
oSIST prEN ISO 19629:2022
01-januar-2022
Fina keramika (sodobna keramika, sodobna tehnična keramika) - Termofizikalne
lastnosti keramičnih kompozitov - Ugotavljanje enodimenzionalne toplotne
difuzivnosti z bliskovno metodo (ISO 19629:2018)
Fine ceramics (advanced ceramics, advanced technical ceramics) - Thermophysical

properties of ceramic composites - Determination of unidimensional thermal diffusivity by

flash method (ISO 19629:2018)
Hochleistungskeramik - Thermophysikalische Eigenschaften keramischer
Verbundwerkstoffe - Bestimmung der Temperaturleitfähigkeit (ISO 19629:2018)
Céramiques techniques - Propriétés thermophysiques des composites céramiques -

Détermination de la diffusivité thermique unidimensionnelle par la méthode flash (ISO

19629:2018)
Ta slovenski standard je istoveten z: prEN ISO 19629
ICS:
81.060.30 Sodobna keramika Advanced ceramics
oSIST prEN ISO 19629:2022 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN ISO 19629:2022
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oSIST prEN ISO 19629:2022
INTERNATIONAL ISO
STANDARD 19629
First edition
2018-08
Fine ceramics (advanced ceramics,
advanced technical ceramics) —
Thermophysical properties of ceramic
composites — Determination of
unidimensional thermal diffusivity by
flash method
Céramiques techniques — Propriétés thermophysiques des
composites céramiques — Détermination de la diffusivité thermique
unidimensionnelle par la méthode flash
Reference number
ISO 19629:2018(E)
ISO 2018
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oSIST prEN ISO 19629:2022
ISO 19629:2018(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2018

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]
Fax: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2018 – All rights reserved
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oSIST prEN ISO 19629:2022
ISO 19629:2018(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 1

4 Principle ........................................................................................................................................................................................................................ 2

5 Apparatus ..................................................................................................................................................................................................................... 2

5.1 Heat pulse source.................................................................................................................................................................................. 2

5.2 Test chamber ............................................................................................................................................................................................ 2

5.3 Detectors ...................................................................................................................................................................................................... 2

5.3.1 Measurement of absolute temperature ........................................................................................................ 2

5.3.2 Transient detectors ........................................................................................................................................... ............. 3

5.4 Data acquisition ..................................................................................................................................................................................... 3

6 Test specimens........................................................................................................................................................................................................ 4

7 Test specimen preparation ........................................................................................................................................................................ 4

7.1 Machining and preparation .......................................................................................................................................................... 4

7.2 Number of test specimens ............................................................................................................................................................. 4

8 Procedure..................................................................................................................................................................................................................... 4

8.1 Calibration of apparatus ................................................................................................................................................................. 4

8.2 Procedure .................................................................................................................................................................................................... 4

9 Results ............................................................................................................................................................................................................................. 5

9.1 Determination of the thermal diffusivity ......................................................................................................................... 5

9.2 Sources of uncertainties.................................................................................................................................................................. 5

10 Test report ................................................................................................................................................................................................................... 5

Annex A (informative) Unidimensional thermal model ................................................................................................................... 9

Annex B (informative) Experimental characteristics for optimal measurements ............................................11

Bibliography .............................................................................................................................................................................................................................12

© ISO 2018 – All rights reserved iii
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oSIST prEN ISO 19629:2022
ISO 19629:2018(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

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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).

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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.

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 © ISO 2018 – All rights reserved
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oSIST prEN ISO 19629:2022
INTERNATIONAL STANDARD ISO 19629:2018(E)
Fine ceramics (advanced ceramics, advanced technical
ceramics) — Thermophysical properties of ceramic
composites — Determination of unidimensional thermal
diffusivity by flash method
1 Scope

This document describes the flash method for the determination of thermal diffusivity of ceramic

matrix composites with continuous fibre reinforcement.

In order to conform with the unidimensional heat transfer hypothesis, the experimental conditions are

defined such that the material behaves in a homogeneous manner. This involves performing tests in one

symmetry axis of the composite.

The method is applicable to materials which are physically and chemically stable during the

measurement, and covers the range of temperature from 100 K to 2 800 K. It is suitable for the

−4 2 −1 −7 2 −1
measurement of thermal diffusivity values in the range 10 m ∙s to 10 m ∙s .
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 20507, Fine ceramics (advanced ceramics, advanced technical ceramics) — Vocabulary

EN 60584-1, Thermocouples — Part 1: Reference tables (IEC 60584‑1:1995)
3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 20507 and the following apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https: //www .iso .org/obp
— IEC Electropedia: available at http: //www .electropedia .org/
3.1
thermal diffusivity

ratio of the thermal conductivity to the product of the bulk density and the specific heat capacity

3.2
transient half time
1/2

time from the initiation of the pulse until the increase of the temperature on the back face of the test

specimen reaches one half of the maximum temperature increase
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oSIST prEN ISO 19629:2022
ISO 19629:2018(E)
3.3
thickness
dimension of the test specimen in the direction of heat transfer measurement
4 Principle

One side of a plane- and parallel-face test piece is exposed to a uniformly distributed energy pulse that

is of very short duration compared with the transient half time.

The transient temperature rise (ΔT) on the opposite face (back face) or a quantity directly proportional

to ΔT is recorded as a function of time (t) (see Figure 1).

The thermal diffusivity is obtained by comparing the experimental thermogram with a theoretical

model, which is a unidimensional analytical thermal model, with two parameters, as described in

Annex A. If other models are used, they are to be specified in the test report.
5 Apparatus
5.1 Heat pulse source
The heat pulse source may be a flash tube or a pulse laser.

The pulse energy shall be as uniform as possible over the front face of the test piece.

5.2 Test chamber

The test chamber shall be either a furnace or a cryostat, capable of operation within the temperature

range required, or a draught proof enclosure for ambient temperature measurement.

The design of the furnace shall meet the following requirements:

a) it shall contain a working area in which the spatial temperature gradient is sufficiently low (≤5 K

over working area width) to result in a homogeneous temperature on the test piece;

b) in steady state conditions, the drift in temperature shall be less than 0,01 K/s;

c) the heat pulse source may be placed either inside the furnace or outside the furnace; in the latter

case, the furnace shall be fitted with a window, transparent to the pulse radiation;

d) the furnace shall provide suitable access for measurement of ΔT or a quantity directly proportional

to ΔT on the back face of the test piece.

When the test is performed under gas, the test piece should be in a horizontal position in order to

reduce convection effects of the gas on the specimen.

NOTE Measurement under vacuum will reduce convection losses and will limit the oxidation phenomena at

high temperature.
5.3 Detectors
5.3.1 Measurement of absolute temperature

The temperature of the test piece shall be measured either with a thermocouple (in accordance with

EN 60584-1) or with an optical pyrometer.
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oSIST prEN ISO 19629:2022
ISO 19629:2018(E)
5.3.2 Transient detectors

The detector shall be either a quantum radiation detector, a thermocouple or any other means that

does not disturb the measurement of the transient response of the specimen. It shall be capable of

detecting changes of 0,05 K in the temperature of the test piece, with a linear response over the range of

temperature change less than or equal to 5 K.

The choice of the detector depends primarily on both the temperature range in which the measurement

is to be performed and the characteristic time of the sample. The first parameter sets the spectral

range for which the detection sensitivity of the detector shall be maximum; the second parameter fixes

its time constant.
It shall have a response time as shown in Formula (1).
t ≤ 0,002 h /a (1)
where
t is the response time, in seconds (s);
...