ISO 23486:2021

Metallic and other inorganic coatings - Measurement of Young’s modulus of thermal barrier coatings at elevated temperature by flexural resonance method

This document specifies a method for measuring the in-plane Young’s modulus of thermal barrier coatings (TBCs) formed on substrates, from room temperature up to 1 000 °C.

Titre manque

General Information

• Status: Published
• Publication Date: 12-Apr-2021
• ICS: 25.220.40 - Metallic coatings
• Technical Committee: ISO/TC 107 - Metallic and other inorganic coatings
• Drafting Committee: ISO/TC 107/WG 1 - Thermal spraying
• Current Stage: 6060 - International Standard published
• Start Date: 13-Apr-2021
• Due Date: 09-Jul-2021
• Completion Date: 13-Apr-2021

Relations

• Consolidated By: ISO 4608:2023 - Plastics - Homopolymer and copolymer resins of vinyl chloride for general use - Determination of plasticizer absorption at room temperature
• Effective Date: 06-Jun-2022

Overview

ISO 23486:2021 specifies a standardized method to measure the in‑plane Young’s modulus of thermal barrier coatings (TBCs) formed on metallic substrates using the flexural resonance method at temperatures from room temperature up to 1 000 °C. The standard is intended for multilayer TBC systems consisting of a metallic bond coat (BC) and a ceramic top coat (TC) applied to heat‑resistant metallic substrates (e.g., nickel or cobalt‑based superalloys).

Key topics and technical requirements

• Measurement principle: Determination of Young’s modulus by measuring the flexural resonance frequency of three specimen types - the substrate, substrate+BC and substrate+BC+TC - at the test temperature and applying composite beam vibration theory.
• Temperature range: Measurements and pre‑conditioning up to 1 000 °C; specimens are recommended to be preheated at the maximum test temperature for about 2 hours to stabilize microstructure and mechanical response.
• Apparatus: A flexural resonance system combined with a controlled heating device (furnace). Suspension by a heat‑resistant thread (e.g., alumina yarn) is specified to permit free vibration.
• Specimen geometry and tolerances: Beam specimens with defined length, width and thickness ranges (e.g., substrate thickness 1.5–2.5 mm; width ≥ 5.0 mm with limits relative to length). Coating thickness bounds and ratios for BC and TC are specified to ensure valid calculations.
• Measurement procedure: Precise dimension and mass measurements (referencing ISO 13385, ISO 3611, ISO 1463) followed by resonance frequency measurement at stabilized temperatures.
• Calculations: Young’s moduli for the substrate, BC and TC are calculated from measured resonance frequencies, dimensions and masses using the formulas provided; results are reported per clause 9.
• Reporting requirements: Test report must include materials, spraying conditions, specimen dimensions and masses, preheat and test temperature conditions, resonance frequencies, computed Young’s moduli, deviations and date of measurement.

Applications and users

ISO 23486 is practical for:

• Coating laboratories performing mechanical characterization of TBC systems
• Gas‑turbine and aero‑engine manufacturers validating coating performance at high temperatures
• Materials engineers and researchers studying thermal protection systems and high‑temperature modulus changes
• Quality control and certification bodies assessing TBC mechanical properties for lifecycle prediction

Typical use cases: high‑temperature property verification of thermal barrier coatings for power‑generation turbines, hot‑section components testing, research on coating degradation and design of multilayer TBC systems.

Related standards

• ISO 19477 - Young’s modulus of TBCs by beam bending (room temperature)
• ISO 17561 - Sonic resonance apparatus requirements
• ISO 14188 - TBC thermal cycle/thermal shock tests
• ISO 1463, ISO 3611, ISO 13385 - dimensional and coating thickness measurement methods

Keywords: ISO 23486:2021, thermal barrier coatings, Young’s modulus, flexural resonance method, elevated temperature testing, TBC measurement, bond coat, top coat, high‑temperature mechanical properties.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 23486
First edition
2021-04
Metallic and other inorganic
coatings — Measurement of Young’s
modulus of thermal barrier coatings
at elevated temperature by flexural
resonance method
Reference number
©
ISO 2021
© ISO 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
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Published in Switzerland
ii © ISO 2021 – All rights reserved

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Apparatus for measuring resonance frequency . 2
6 Specimen . 3
6.1 Shape and dimensions . 3
6.2 Preheat treatment . 4
7 Measuring procedure . 4
7.1 Dimension and mass of specimen . 4
7.2 Resonance frequency . . 5
8 Calculation of Young’s modulus . 6
8.1 General . 6
8.2 Young’s modulus of the substrate . 6
8.3 Young’s modulus of BC . 6
8.4 Young’s modulus of TC . 7
9 Test report . 7
Annex A (informative) An example of the apparatus for measuring the resonance frequency .9
Bibliography .10
Foreword
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This document was prepared by Technical Committee ISO/TC 107, Metallic and other inorganic coatings.
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iv © ISO 2021 – All rights reserved

Introduction
Thermal barrier coatings (TBCs) are highly advanced material systems, generally applied to surfaces
of hot-section components made of nickel or cobalt-based superalloys, such as combustors, blades and
vanes of power-generation gas turbines in thermal power plants and aero-engines operated at elevated
temperatures.
The function of these coatings is to protect metallic components for extended periods at elevated
temperatures by employing thermally insulating materials which can sustain an appreciable
temperature difference between load-bearing alloys and coating surfaces. These coatings permit the
high-temperature operation by shielding these components, thereby extending their lives.
Although Young’s modulus is an important property of TBCs, the existing ISO 19477 only describes a
method for measuring this parameter at room temperature.
This document specifies a method for measuring the Young’s modulus of TBCs that consist of multilayers
formed on substrate by thermal spraying, from room temperature up to elevated temperature.
INTERNATIONAL STANDARD ISO 23486:2021(E)
Metallic and other inorganic coatings — Measurement of
Young’s modulus of thermal barrier coatings at elevated
temperature by flexural resonance method
1 Scope
This document specifies a method for measuring the in-plane Young’s modulus of thermal barrier
coatings (TBCs) formed on substrates, from room temperature up to 1 000 °C.
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 1463, Metallic and oxide coatings — Measurement of coating thickness — Microscopical method
ISO 3611, Geometrical product specifications (GPS) — Dimensional measuring equipment: Micrometers for
external measurements — Design and metrological characteristics
ISO 13385 (all parts), Geometrical product specifications (GPS) — Dimensional measuring equipment
ISO 14188:2012, Metallic and other inorganic coatings — Test methods for measuring thermal cycle
resistance and thermal shock resistance for thermal barrier coatings
ISO 17561:2016, Fine ceramics (advanced ceramics, advanced technical ceramics) — Test method for
elastic moduli of monolithic ceramics at room temperature by sonic resonance
ISO 19477, Metallic and other inorganic coatings — Measurement of Young's modulus of thermal barrier
coatings by beam bending
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 14188 and ISO 19477 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 barrier coating
TBC
two-layer coating consisting of a metallic bond coat (BC) and a ceramic top coat (TC), in ord
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