ISO 23458:2020

Fine ceramics (advanced ceramics, advanced technical ceramics) — Test method for determining thermal expansion coefficient and residual stress of CVD ceramic coatings

This document specifies a test method for determining thermal expansion coefficient up to 2 300 K and the residual stress of chemical vapour deposition (CVD) ceramic coatings (thickness > 0,03 mm) at room temperature. Procedures for test piece preparation, test modes, heat rate, data collection, property calculations and reporting procedures are given. This document applies to CVD ceramic coatings on metal or ceramic substrates. This test method can be used for material research, quality control, characterization and design data-generation purposes.

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General Information

• Status: Published
• Publication Date: 11-May-2020
• ICS: 81.060.30 - Advanced ceramics
• Technical Committee: ISO/TC 206 - Fine ceramics
• Drafting Committee: ISO/TC 206/WG 10 - Coatings
• Current Stage: 6060 - International Standard published
• Start Date: 08-May-2020
• Due Date: 19-Jun-2021
• Completion Date: 12-May-2020

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 23458
First edition
2020-05
Fine ceramics (advanced ceramics,
advanced technical ceramics) — Test
method for determining thermal
expansion coefficient and residual
stress of CVD ceramic coatings
Reference number
ISO 23458:2020(E)
©
ISO 2020

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ISO 23458:2020(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2020
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ii © ISO 2020 – All rights reserved

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ISO 23458:2020(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 General . 2
5.2 Heating and cooling device. 3
5.3 Temperature measurement . 3
5.4 Test piece mounting . 3
5.5 Data recording system . 4
5.6 Dimensional measuring devices . 4
6 Specimens . 4
6.1 Test piece . 4
6.2 Dimensions . 5
6.3 Test piece preparation . 6
6.3.1 General. 6
6.3.2 Test piece handling and storage . 6
6.3.3 Number of test pieces . 6
7 Test procedure . 6
7.1 Measurement of the test piece dimensions . 6
7.2 Measurement of the elastic modulus . 6
7.3 Measurement of the thermal expansion coefficient of CVD coatings . 6
7.4 Calculation of the residual stress in CVD coatings . 7
8 Calculation . 7
8.1 Thermal expansion coefficient of the CVD ceramic coatings, α . 7
c
8.2 Residual stress in CVD coatings, σ . 7
c
9 Test report . 8
Bibliography . 9
© ISO 2020 – All rights reserved iii

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ISO 23458:2020(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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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
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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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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 2020 – All rights reserved

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INTERNATIONAL STANDARD ISO 23458:2020(E)
Fine ceramics (advanced ceramics, advanced technical
ceramics) — Test method for determining thermal
expansion coefficient and residual stress of CVD ceramic
coatings
1 Scope
This document specifies a test method for determining thermal expansion coefficient up to 2 300 K
and the residual stress of chemical vapour deposition (CVD) ceramic coatings (thickness > 0,03 mm)
at room temperature. Procedures for test piece preparation, test modes, heat rate, data collection,
property calculations and reporting procedures are given.
This document applies to CVD ceramic coatings on metal or ceramic substrates. This test method can
be used for material research, quality control, characterization and design data-generation purposes.
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 17139, Fine ceramics (advanced ceramics, advanced technical ceramics) — Thermophysical properties
of ceramic composites — Determination of thermal expansion
ISO 19603, Fine ceramics (advanced ceramics, advanced technical ceramics) — Test method for determining
elastic modulus and bending strength of thick ceramic coatings
IEC 60584-1, Thermocouples — Part 1: EMF specifications and tolerances
3 Terms and definitions
For the purposes of this document, the following terms and definitions 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
relative method
indirect test method to obtain the measured parameter
Note 1 to entry: The expected parameter A is usually difficult to measure directly, but parameters B and C are
known parameters or easy to obtain. If the analytical relationship of A = f (B, C) is established, the parameter A
can be calculated.
3.2
linear thermal expansion
positive or negative change in one dimension that occurs when a material is subjected to a change in
temperature
© ISO 2020 – All rights reserved 1

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ISO 23458:2020(E)

4 Principle
The deformation of a coated bar during heating or cooling involves two effect factors, i.e. thermal
expansion coefficient and residual stress in the coating and the substrate. The thermal expansion
coefficient is a material characteristic. However, the residual stresses in the coating are not only due to
a material property but depend also on the size of the component and the cross-sectional area ratio of
the coating and substrate.
The thermal
...