ISO 21465

Test method for CMAS corrosion of thermal/environmental barrier coatings under dynamic thermal cycling

This document specifies requirements for the test method of the CMAS corrosion of thermal/environmental barrier coatings under dynamic thermal cycling, including the process and the determination of failure after corrosion. The document does not apply to such coatings on plastics to be used for aerospace, electronics, and other engineering fields.

Méthode d'essai de la corrosion par les CMAS des systèmes barrières thermiques/environnementales dans le cadre d'un cyclage thermique dynamique

General Information

• Status: Not Published
• ICS: 25.220.01 - Surface treatment and coating in general
• Technical Committee: ISO/TC 107 - Metallic and other inorganic coatings
• Drafting Committee: ISO/TC 107 - Metallic and other inorganic coatings
• Current Stage: 6000 - International Standard under publication
• Due Date: 30-Jan-2025
• Completion Date: 30-Jan-2025

Standards Content (Sample)

FINAL DRAFT
International
Standard
ISO/FDIS 21465
ISO/TC 107
Test method for CMAS corrosion
Secretariat: KATS
of thermal/environmental barrier
Voting begins on:
coatings under dynamic thermal
2024-12-04
cycling
Voting terminates on:
2025-01-29
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT,
WITH THEIR COMMENTS, NOTIFICATION OF ANY
RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE
AND TO PROVIDE SUPPOR TING DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
Reference number
ISO/FDIS 21465:2024(en) © ISO 2024

FINAL DRAFT
ISO/FDIS 21465:2024(en)
International
Standard
ISO/FDIS 21465
ISO/TC 107
Test method for CMAS corrosion
Secretariat: KATS
of thermal/environmental barrier
Voting begins on:
coatings under dynamic thermal
cycling
Voting terminates on:
RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT,
WITH THEIR COMMENTS, NOTIFICATION OF ANY
RELEVANT PATENT RIGHTS OF WHICH THEY ARE AWARE
AND TO PROVIDE SUPPOR TING DOCUMENTATION.
© ISO 2024
IN ADDITION TO THEIR EVALUATION AS
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
LOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL
or ISO’s member body in the country of the requester.
TO BECOME STAN DARDS TO WHICH REFERENCE MAY BE
MADE IN NATIONAL REGULATIONS.
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 Reference number
ISO/FDIS 21465:2024(en) © ISO 2024

ii
ISO/FDIS 21465:2024(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Test methods . 3
5.1 CMAS corrosion under dynamic thermal cycling without thermal gradient .3
5.1.1 CMAS composition .3
5.1.2 CMAS coating .3
5.1.3 Test method .3
5.1.4 Detection of the accurate temperature .3
5.1.5 Determination of failed samples .3
5.1.6 Apparatus .4
5.2 CMAS corrosion under dynamic thermal cycling with thermal gradient.4
5.2.1 CMAS suspension and CMAS precursor solution .4
5.2.2 CMAS concentrations .4
5.2.3 CMAS injection rate .4
5.2.4 Test method .4
5.2.5 Heating temperature and time .5
5.2.6 Determination of failed samples .5
5.2.7 Equipment design .5
6 Test report . 6
Annex A (informative) CMAS corrosion under dynamic thermal cycling without thermal
gradient. 7
Bibliography . 8

iii
ISO/FDIS 21465:2024(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).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
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 107, Metallic and other inorganic coatings.
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/FDIS 21465:2024(en)
Introduction
This document provides the test method for calcia–magnesia–aluminosilicate (CMAS) corrosion of thermal/
environmental barrier coatings (T/EBCs) under dynamic thermal cycling. The CMAS corrosion behaviour
affects the performance and service life of the T/EBCs. The multi-layer structure of the T/EBC is deposited on
Ni-superalloys/SiC-based ceramic substrates using different methods such as atmospheric plasma spraying
(APS), plasma spray-physical vapour deposition (PS-PVD), electron beam physical vapour deposition (EB-
PVD), high-velocity oxygen fuel (HVOF). Therefore, the deposition methods and thickness of T/EBCs should
meet the requirements of service conditions.
CMAS can be in the form of airborne sand, runway debris or volcanic ash in aircraft engines and ambient dust
or fly ash in power generation engines. Gas turbine engines are attacked by the CMAS when the aerospace
spacecraft or aircraft flies above desert and volcanic areas. The diffusion, reaction and viscosity of the molten
CMAS can cause serious corrosion of T/EBC, resulting in the T/EBC's spallation and failure. Consequently,
the operation lifetime of the gas turbine is reduced. Therefore, the behaviour of CMAS corrosion of T/EBCs
is an important assessment index of T/EBCs performance. A unified international test standard is required
to evaluate CMAS corrosion of thermal/environmental barrier coatings (T/EBCs) under dynamic thermal
cycling. This document aims to formulate a standardized and unified test method, including the process and
the failure determination criteria, for the performance of T/EBCs.

v
FINAL DRAFT International Standard ISO/FDIS 21465:2024(en)
Test method for CMAS corrosion of thermal/environmental
barrier coatings under dynamic thermal cycling
1 Scope
This document specifies requirements for the test method of the CMAS corrosion of thermal/environmental
barrier coatings under dynamic thermal cycling, including the process and the determination of failure after
corrosion.
The document does not apply to such coatings on plastics to be used for aerospace, electronics and other
engineering fields.
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 13123, Metallic and other inorganic coatings — Test method of cyclic heating for thermal-barrier coatings
under temperature gradient
ISO 14188, Metallic and other inorganic coatings — Test methods for measuring thermal cycle resistance and
thermal shock resistance for thermal barrier coatings
ISO 18555, Metallic and other inorganic coatings — Determination of thermal conductivity of thermal barrier
coatings
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 13123, ISO 14188, and ISO 18555,
and the following 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
thermal/environmental barrier coating
T/EBC
protective coating on the superalloy or SiC-based substrate to reduce the heat transfer from the outside
topcoat layer through the coating to the substrate
Note 1 to entry: T/EBC inhibits the oxidation of the substrate, increases the operation temperature and improves
the service life of the substrate when exposed to harsh environments, such as air, water vapour and molten calcia-
magnesia-aluminosilicate (3.2) conditions. Generally, a bond coat layer is placed between the T/EBC and substrate to
mitigate the coefficient of thermal expansion incompatibilities. Figure 1 shows the schematic diagram of the T/EBC on
the substrate. The T/EBC is sprayed on the bond coat layer using APS, PS-PVD, EB-PVD, HVOF, etc.

ISO/FDIS 21465:2024(en)
Key
1 thermal/environmental barrier coating (T/EBC)
2 thermally grown oxide (TGO)
3 bond coat (BC)
4 substrate
Figure 1 — Diagrammatic representation of a section of T/EBC
3.2
calcia–magnesia–aluminosilicate
CMAS
mixture consisting of CaO, MgO, Al O and SiO
2 3 2
Note 1 to entry: CMAS can be in the form of airborne sand, runway debris or volcanic ash in aircraft engines and
ambient dust or fly ash in power generation engines.
3.3
dynamic thermal cycling
system comprising the heating, holding and cooling process
...

2024-09-20
ISO/FDIS 21465 : 2024(en)
ISO /TC 107/N2906
Secretariat: KATS
Date: 2024-11-20
Test method for CMAS corrosion of thermal/environmental barrier
coatings under dynamic thermal cycling
FDIS stage
ISO/FDIS 21465:2024(en)
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: + 41 22 749 01 11
EmailE-mail: [e-mail]
Website: www.iso.orgwww.iso.org
Published in Switzerland
ii © ISO 2024 – All rights reserved
ii
ISO/FDIS 21465:2024(en)
Contents
Foreword . iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 3
5 Test methods . 3
5.1 CMAS corrosion under dynamic thermal cycling without thermal gradient . 3
5.2 CMAS corrosion under dynamic thermal cycling with thermal gradient . 5
6 Test report . 7
Annex A (informative) CMAS corrosion under dynamic thermal cycling without thermal
gradient . 8
Bibliography . 10

Foreword . iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 3
5 Test methods . 3
5.1 CMAS corrosion under dynamic thermal cycling without thermal gradient . 3
5.1.1 CMAS composition . 3
5.1.2 CMAS coating . 3
5.1.3 Test method . 3
5.1.4 Detection of the accurate temperature . 3
5.1.5 Determination of failed samples . 4
5.1.6 Apparatus . 4
5.2 CMAS corrosion under dynamic thermal cycling with thermal gradient . 4
5.2.1 CMAS suspension and CMAS precursor solution . 4
5.2.2 CMAS concentrations . 4
5.2.3 CMAS injection rate . 5
5.2.4 Test method . 5
5.2.5 Heating temperature and time . 5
5.2.6 Determination of failed samples . 5
5.2.7 Equipment design . 5
6 Test report . 6
Annex A (informative) CMAS corrosion under dynamic thermal cycling without thermal gradient8
Bibliography . 9

© ISO 2024 – All rights reserved
iii
ISO/FDIS 21465:2024(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/directiveswww.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent rights
in respect thereof. As of the date of publication of this document, ISO had not received notice of (a) patent(s)
which may be required to implement this document. However, implementers are cautioned that this may not
represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents.www.iso.org/patents. ISO shall not be held responsible for identifying any or all such
patent rights.
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.htmlwww.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 107, Metallic and other inorganic coatings.
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.htmlwww.iso.org/members.html.
iv © ISO 2024 – All rights reserved
iv
ISO/FDIS 21465:2024(en)
Introduction
This document provides the test method for calcia–magnesia–aluminosilicate (CMAS) corrosion of
thermal/environmental barrier coatings (T/EBCs) under dynamic thermal cycling. The CMAS corrosion
behaviour affects the performance and service life of the T/EBCs. The multi-layer structure of the T/EBC is
deposited on Ni-superalloys/SiC-based ceramic substrates using different methods such as atmospheric
plasma spraying (APS), plasma spray-physical vapour deposition (PS-PVD), electron beam physical vapour
deposition (EB-PVD), high-velocity oxygen fuel (HVOF). Therefore, the deposition methods and thickness of
T/EBCs should meet the requirements of service conditions.
CMAS can be in the form of airborne sand, runway debris, or volcanic ash in aircraft engines, and ambient dust
or fly ash in power generation engines. Gas turbine engines are attacked by the CMAS when the aerospace
spacecraft or aircraft flies above the desert and volcanic areas. The diffusion, reaction, and viscosity of the
molten CMAS wouldcan cause serious corrosion of T/EBC, resulting in the T/EBC's spallation and failure.
Consequently, the operation lifetime of the gas turbine is reduced. Therefore, the behaviour of CMAS corrosion
of T/EBCs is an important assessment index of T/EBCs performance. A unified international test standard is
required to evaluate CMAS corrosion of thermal/environmental barrier coatings (T/EBCs) under dynamic
thermal cycling. This document aims to formulate a standardized and unified test method, including the
process and the failure determination criteria, for the performance of T/EBCs.
© ISO 2024 – All rights reserved
v
ISO/FDIS 21465:2024(en)
Test method for CMAS corrosion of thermal/environmental barrier
coatings under dynamic thermal cycling
1 Scope
This document specifies requirements for the test method of the CMAS corrosion of thermal/environmental
barrier coatings under dynamic thermal cycling, including the process and the determination of failure after
corrosion.
The document does not apply to such coatings on plastics to be used for aerospace, electronics, and other
engineering fields.
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 13123, Metallic and other inorganic coatings — Test method of cyclic heating for thermal-barrier coatings
under temperature gradient
ISO 14188, Metallic and other inorganic coatings — Test methods for measuring thermal cycle resistance and
thermal shock resistance for thermal barrier coatings
ISO 18555, Metallic and other inorganic coatings — Determination of thermal conductivity of thermal barrier
coatings
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 13123, ISO 14188, and ISO 18555,
and the following 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/obphttps://www.iso.org/obp
— — IEC Electropedia: available at https://www.electropedia.org/https://www.electropedia.org/
3.1 3.1
thermal/environmental barrier coating
T/EBC
protective coating on the superalloy or SiC-based substrate to reduce the heat transfer from the outside
topcoat layer through the coating to the substrate
Note 1 to entry: T/EBC inhibits the oxidation of the substrate, increases the operation temperature, and improves the
service life of the substrate when exposed to harsh environments, such as air, water vapour, and molten CMAS (3.2)calcia-
magnesia-aluminosilicate (3.2) conditions. Generally, a bond coat layer is placed between the T/EBC and substrate to
mitigate the coefficient of thermal expansion incompatibilities. Figure 1Figure 1 shows the schematic diagram of the
T/EBC on the substrate. The T/EBC is sprayed on the bond coat layer using APS, PS-PVD, EB-PVD, HVOF, etc.
© ISO 2024 – All rights reserved
ISO/FDIS 21465:2024(en)
Key
1 thermal/environmental barrier coating (T/EBC)
2 thermally grown oxide (TGO)
3 bond coat (BC)
4 substrate
Figure 1 — Diagrammatic representation of a section of T/EBC
3.2 3.2
calcia–magnesia–aluminosilicate
CMAS
mixture consisting of CaO, MgO, Al O , and SiO
2 3 2
Note 1 to entry: CMAS can be in the form of airborne sand, runway debris, or volcanic ash in aircraft engines, and
ambient dust or fly ash in power generation engines.
2 © ISO 2024 – All rights reserved
ISO/FDIS 21465:2024(en)
3.3 3.3
dynamic thermal cycling
system co
...