ISO 23737:2021

Fine ceramics (advanced ceramics, advanced technical ceramics) — Methods for evaluating wear and friction characteristics of fine ceramic thin films under dry and humid conditions

This document specifies a method for testing the wear resistance and friction coefficient for fine ceramic thin films in dry and high-humidity environments, where such films have a thickness of up to approximately 1 µm and are deposited on a substrate or a base, including a thin substrate or a very thin organic polymer film base.

Céramiques techniques — Méthodes pour l'évaluation des caractéristiques d'usure et de frottement des films minces de céramiques techniques en conditions sèches et humides

General Information

• Status: Published
• Publication Date: 23-Aug-2021
• 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: 24-Aug-2021
• Due Date: 19-Dec-2021
• Completion Date: 24-Aug-2021

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 23737
First edition
2021-08
Fine ceramics (advanced ceramics,
advanced technical ceramics) —
Methods for evaluating wear and
friction characteristics of fine ceramic
thin films under dry and humid
conditions
Céramiques techniques — Méthodes pour l'évaluation des
caractéristiques d'usure et de frottement des films minces de
céramiques techniques en conditions sèches et humides
Reference number
ISO 23737:2021(E)
©
ISO 2021

---------------------- Page: 1 ----------------------
ISO 23737:2021(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2021
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]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2021 – All rights reserved

---------------------- Page: 2 ----------------------
ISO 23737:2021(E)

Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Test specimens. 2
5 Measurement principle . 2
6 Testing room environment . 2
7 Wear formation test apparatus . 3
8 Test specimen preparation . 5
9 Test specimen pretreatment . 5
9.1 General . 5
9.2 Test specimen cleaning . 5
9.3 Test specimen drying . 5
10 Environmental conditions for the formation of the wear and the evaluation of
friction coefficient . 6
10.1 General . 6
10.2 Dry environment . 6
10.3 High-humidity environment . 6
11 Wear motion conditions . 6
11.1 Reciprocating wear conditions . 6
11.2 Rotating disc wear conditions . 7
12 E valuation of wear track cross-section formed on thin film test specimen surface .8
13 Evaluation of volume of worn portion on indenter ball surface .8
13.1 General . 8
13.2 Observation of indenter ball wear surface profile . 8
13.3 Calculation of volume of worn portion on indenter ball surface . 9
14 Investigations of morphology and elemental distribution maps for wear tracks on
thin film test specimens and worn sections on indenter balls .9
14.1 General . 9
14.2 Observation of the morphology . 9
14.3 Investigations of elemental distribution maps .10
15 Calculation of friction coefficient .10
16 Testing procedures .10
16.1 Measurement of thickness of thin film test specimen .10
16.2 Thin film test specimen preparation and cleaning .10
16.3 Setting of wear formation conditions .10
16.3.1 General.10
16.3.2 Wear formation conditions for a dry environment .11
16.3.3 Wear formation conditions for a high-humidity environment .11
16.4 Wear formation .11
16.4.1 Start of wear formation on the thin film test specimen .11
16.4.2 Friction force measurement .11
16.5 E valuation of thin film test specimen surface and indenter ball surface after wear
formation .11
16.5.1 General.11
16.5.2 Measurement of wear track cross-section on thin film test specimen .11
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ISO 23737:2021(E)

16.5.3 Evaluation of volume of worn portion on indenter ball surface .11
16.5.4 Investigations of morphology and elemental distribution maps .11
16.6 Calculation of friction coefficient .11
17 Precautions for summarization of test results .12
18 Test report .12
Annex A (informative) Example of reciprocating slide wear results and rotating slide wear
results .13
Annex B (informative) Method of holding polymer film or thin glass plate with a thickness
of < 200 µm in sliding wear formations .15
Annex C (informative) Effects of combining thin film materials and indenter materials
in sliding wear tests.17
Annex D (informative) Investigation of optimal load for indenter .22
Annex E (informative) Quantification of wear track cross-section area .24
Annex F (informative) Examples of investigations of morphology and elemental
distribution maps for wear tracks on thin films and worn sections of indenter balls .25
Bibliography .30
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ISO 23737:2021(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 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 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.
© ISO 2021 – All rights reserved v

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ISO 23737:2021(E)

Introduction
Fine ceramic thin films are used in a wide variety of applications, such as sensors, actuators or other
micromechanical elements; display elements; memory elements; recording media; optical elements;
packaging films; and films and glass for building construction and vehicles. In the industrial application
of fine ceramic thin films, resistance to wear is an important index for evaluation. The resistance
to wear of fine ceramic thin films is greatly affected by environmental humidity and the humidity
history of the thin film. Fine ceramic thin films are also used in different humidity environments,
necessitating standards for the evaluation of wear resistance and the friction coefficient under a
wide humidity range. Standards published to date concerning wear resistance testing assume only
a temperature environment of 23 °C and a relative humidity of 50 %; the thickness of the thin films
subject to evaluation is also comparatively large, at several to 10 µm. These testing procedures are
inappropriate for evaluating the wear resistance of fine ceramic thin films that have a thickness of up
to approximately 1 µm and are applied for electronic and optical devices, because the wear resistance
for a smaller indentation load is affected by the relative humidity of the test environment, i.e. the
mechanisms employed in the wear test for fine ceramic thin films with a smaller indentation load are
strongly affected by the relative humidity of the test environment. Therefore, the wear test for fine
ceramic thin films should be performed under a regulated relative humidity condition. This document
provides measurement methods that facilitate the accurate evaluation of wear resistance for fine
ceramic thin films in dry and high-humidity environments, where such films have a thickness of up
to approximately 1 µm and are deposited on a thin substrate or an organic polymer film base. This
document has been enacted to facilitate industrial development through the prompt dissemination of
these measurement methods.
vi © ISO 2021 – All rights reserved

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INTERNATIONAL STANDARD ISO 23737:2021(E)
Fine ceramics (advanced ceramics, advanced technical
ceramics) — Methods for evaluating wear and friction
characteristics of fine ceramic thin films under dry and
humid conditions
1 Scope
This document specifies a method for testing the wear resistance and friction coefficient for fine
ceramic thin films in dry and high-humidity environments, where such films have a thickness of up to
approximately 1 µm and are deposited on a substrate or a base, including a thin substrate or a very thin
organic polymer film base.
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 3274, Geometrical Product Specifications (GPS) — Surface texture: Profile method — Nominal
characteristics of contact (stylus) instruments
ISO 13565-1, Geometrical Product Specifications (GPS) — Surface texture: Profile method; Surfaces having
stratified functional properties — Part 1: Filtering and general measurement conditions
ISO 13565-2, Geometrical Product Specifications (GPS) — Surface texture: Profile method; Surfaces having
stratified functional properties — Part 2: Height characterization using the linear material ratio curve
ISO 20507, Fine ceramics (advanced ceramics, advanced technical ceramics) — Vocabulary
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 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
wear
phenomenon leading to progressive loss or progressive displacement from the surface of a solid
material due to motion relative to a contacting body
3.2
frictional force
resistive force exerted on an opposing body when bodies in contact move or tend to slide against each
other
3.3
friction coefficient
dimensionless ratio of frictional force to the normal force applied
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ISO 23737:2021(E)

3.4
wear test
test for evaluating friction and wear characteristics caused by sliding contact motion
Note 1 to entry: In a narrow sense, the term “wear test” implies the process of wear formation on the test
specimen due to a sliding motion; in a broad sense, it implies procedures such as specimen preparation, wear
formation, friction coefficient measurements, and evaluations of the wear track and the worn portion formed on
the counter material.
3.5
drying chamber
hermetically sealed vessel for eliminating moisture on a test specimen surface while the test specimen
remains held in a vacuum
3.6
relative humidity
ratio of water vapour partial pressure to saturated vapour pressure at a given temperature
3.7
dry air
air with a dew point of −60 °C or lower at an absolute pressure of 101,3 kPa
3.8
dry nitrogen
nitrogen with a dew point of −60 °C or lower at an absolute pressure of 101,3 kPa
4 Test specimens
Use fine ceramic thin films that have a thickness of up to approximately 1 µm and are deposited on
a silicon wafer, glass, organic polymer film or other such substrate or base. Provided that the test
specimens can be fitted on a wear testing apparatus as described in this document, the test specimen
dimensions and shape are of no concern. However, the thickness in the area where the wear formation
is performed shall be uniform.
5 Measurement principle
The wear properties of ceramic thin films are greatly affected by environmental humidity and the
humidity history of the thin film. Consequently, the wear resistance of a thin film test specimen should
be evaluated accurately by measuring wear of the thin film test specimen in dry and high-humidity
environments.
A reciprocating wear formation method or a rotating disc wear formation method shall be used as the
method for evaluating wear. Details of the principles pertaining to a reciprocating wear test method
are given in EN 1071-12. Details of the principles pertaining to a rotating disc wear test method are
given in ISO 20808 and EN 1071-13.
This document addresses both methods, i.e. a reciprocating wear test method and a rotating disc wear
test method. Annex A provides an example of results from testing carried out using a reciprocating
wear test method and a rotating disc wear test method.
6 Testing room environment
Measurements shall be carried out in a location subject to minimal changes in temperature and
humidity. Specifically, testing shall be carried out under the following environmental conditions:
a) testing room temperature: (23 ± 2) °C;
b) testing room relative humidity: 70 % or lower.
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ISO 23737:2021(E)

NOTE If the temperature of the testing room is low, condensation can form on the wear evaluation apparatus.
7 Wear formation test apparatus
7.1 Reciprocating wear tester: The reciprocating wear tester shall consist of a test specimen
holder which retains a thin film test specimen, a drive apparatus which moves a thin film test specimen
reciprocally, a holder which retains and secures an indenter ball, a loading mechanism which applies a
constant load to the indenter ball, an equipment unit for detecting frictional force and a test environment
control sealing mechanism. Figure 1 shows a schematic of a test specimen holding system for a
reciprocating wear tester. Details concerning the reciprocal wear tester are given in EN 1071-12.
Key
1 indenter with a lateral force measurement system
2 test specimen
3 test specimen holder
4 wear track
Figure 1 — Schematic of a reciprocating wear tester (indicating the test specimen holding
system)
a) The test specimen holder shall move reciprocally within a horizontal plane and the deflection in
the direction of reciprocal motion shall be adjustable to 0,02 mm or less.
b) The drive apparatus shall allow for the setting of a predetermined sliding speed and changes in
the sliding speed due to variations in the frictional force shall be negligible. A reciprocating sliding
motion counter or equivalent device shall be included.
c) The indenter ball holder shall secure the indenter ball reliably against displacement by the frictional
force generated at the area of contact between the indenter ball and the test specimen, and shall
have high rigidity against induced stress.
d) The indenter ball loading mechanism shall apply and maintain a predetermined load either directly
or through a lever, and by means of a weight or a hydraulic or pressurized air system.
e) The frictional force detection equipment can be a load cell or a leaf spring strain measurement,
rotational torque measurement or other such measurement mechanism as desired, but its insertion
shall not affect the frictional conditions. The measurement precision for the frictional force shall
be within 1 % of the applied load. Use of an in situ linear wear measurement apparatus shall be
optional. If used, the apparatus shall have a depth resolution of less than 0,01 µm.
f) A sealing mechanism for controlling the test atmosphere shall be provided.
7.2 Rotating disc wear tester: The rotating disc wear tester shall consist of a test specimen holder
which retains a thin film test specimen, a drive apparatus which moves a thin film test specimen
rotationally, a holder which retains and secures an indenter ball, a loading mechanism which applies a
constant load to a thin film test specimen, a frictional force detection mechanism and a test environment
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ISO 23737:2021(E)

control sealing mechanism. Figure 2 shows a schematic of a test specimen holding system for a rotating
disc wear tester. Details concerning the rotating disc wear tester are given in ISO 20808.
Key
1 indenter with a lateral force measurement system
2 test specimen
3 test specimen holder
4 wear track
Figure 2 — Schematic of a rotating disk wear tester (indicating the test specimen holding
system)
a) The rotating disc holder shall rotate within a horizontal or vertical plane, the deflection of the
rotational axis shall be adjustable to 0,02 mm or less, and the deflection in the direction of the
rotational axis at the area of contact shall be adjustable to 0,05 mm or less.
b) The drive apparatus shall allow for the setting of a disc rotation speed that provides a predetermined
sliding speed, and changes in the rotational speed due to variations in the frictional force shall be
negligible. A rotational speed counter or equivalent device shall be included.
c) The indenter ball holder shall secure the indenter ball reliably against rotation or displacement
by the frictional force generated at the area of contact between the indenter ball and the disc test
specimen, and shall have high rigidity against induced stress.
d) The indenter ball loading mechanism shall apply and maintain a predetermined load either directly
or through a lever, and by means of a weight or a hydraulic or pressurized air system.
e) The frictional force detection mechanism can be a load cell or a leaf spring strain measurement,
rotational torque measurement, or other such measurement mechanism as desired, but its
insertion shall not affect the frictional conditions. The measurement precision for the frictional
force shall be within 1 % of the applied load. Use of an in situ linear wear measurement apparatus
shall be optional. If used, the apparatus shall have a depth resolution of less than 0,01 µm.
f) A sealing mechanism for controlling the testing environment shall be provided.
7.3 Thermo-hygrostat chamber: The item used shall allow for the setting of relative humidity within
the range of 30 % to 90 % at a temperature of 23 °C. A metal or plastic tube shall be used to introduce air
of a predetermined temperature and humidity into the wear test chamber.
7.4 Dew point meter: The item shall be a capacitance (impedance) hygrometer (dew point meter) or
a chilled mirror dew point meter. Details are given in JIS Z 8806.
7.5 Stylus profilometer: A stylus surface roughness measurement apparatus as specified in
ISO 13565-1 and ISO 13565-2 or one with an equivalent or better precision shall be used.
7.6 Laser interferometric profilometer: The apparatus used shall make use of interference in parallel
light beams with an aligned wave surface to measure the surface profile of a test specimen surface, based
on the interference produced by a phase difference between light reflected from the test piece surface
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ISO 23737:2021(E)

and light reflected from a reference surface serving as a standard. The apparatus used shall have a height
measurement resolution of approximately 10 nm at a magnification power of approximately 100× to
500×. A coherence scanning interferometry (CSI) system for three-dimensional mapping of surface
height is specified in ISO 25178-604.
7.7 Optical microscope: This apparatus shall magnify an object visually for observation using optical
lenses. The apparatus used shall have sufficient resolution at a magnification power of approximately
100× to 800×.
7.8 Scanning electron microscope: This microscope shall be equipped with a basic function for
forming a magnified image using an appropriate method, e.g. secondary electrons obtained from a test
specimen by two-dimensional scanning during irradiation of a test specimen with a tightly focused
electron beam. The apparatus used shall have sufficient resolution at an observational magnification
power of the order of 5 000×. For ceramic thin films, applying an electroconductive coating prior to the
observation is strongly recommended.
7.9 Energy dispersive X-ray spectroscopy: This instrument shall be equipped with an energy
dispersive X-ray (EDX) spectrometer to provide elemental identification by measuring the energy
of X-rays emitted from a specimen due to excitation by the primary electron beam. An elemental
distribution map can be acquired by combining the EDX signal with the position signal of the scanning
primary electron beam.
7.10 Drying chamber: Provided that the chamber can maintain an internal pressure of 4 kPa or lower
and a temperature of 130 °C or higher, its material, form and other details are not of concern.
7.11 Exhauster: A diaphragm pump or similar item shall be used. Provided that the item has an ultimate
pressure of 4 kPa or lower, its type shall not be of concern.
8 Test specimen preparation
Use the same lot or the same batch to prepare thin film test specimens as needed, allowing for
completion of at least three test runs.
9 Test specimen pretreatment
9.1 General
Pretreat test specimens as needed. If test specimens have been exposed to high humidity, for example
cleaned using wa
...

FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 23737
ISO/TC 206
Fine ceramics (advanced ceramics,
Secretariat: JISC
advanced technical ceramics) —
Voting begins on:
2021­05­12 Methods for evaluating wear and
friction characteristics of fine ceramic
Voting terminates on:
2021­07­07
thin films under dry and humid
conditions
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
Reference number
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
ISO/FDIS 23737:2021(E)
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. ISO 2021

---------------------- Page: 1 ----------------------
ISO/FDIS 23737:2021(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2021
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
CH­1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2021 – All rights reserved

---------------------- Page: 2 ----------------------
ISO/FDIS 23737:2021(E)

Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Test specimens. 2
5 Measurement principle . 2
6 Testing room environment . 2
7 Wear formation test apparatus . 3
8 Test specimen preparation . 5
9 Test specimen pretreatment . 5
9.1 General . 5
9.2 Test specimen cleaning . 5
9.3 Test specimen drying . 5
10 Environmental conditions for the formation of the wear and the evaluation of
friction coefficient . 6
10.1 General . 6
10.2 Dry environment . 6
10.3 High-humidity environment . 6
11 Wear motion conditions . 6
11.1 Reciprocating wear conditions . 6
11.2 Rotating disc wear conditions . 7
12 E valuation of wear track cross-section formed on thin film test specimen surface .8
13 Evaluation of volume of worn portion on indenter ball surface .8
13.1 General . 8
13.2 Observation of indenter ball wear surface profile . 8
13.3 Calculation of volume of worn portion on indenter ball surface . 9
14 Investigations of morphology and elemental distribution maps for wear tracks on
thin film test specimens and worn sections on indenter balls .9
14.1 General . 9
14.2 Observation of the morphology . 9
14.3 Investigations of elemental distribution maps .10
15 Calculation of friction coefficient .10
16 Testing procedures .10
16.1 Measurement of thickness of thin film test specimen .10
16.2 Thin film test specimen preparation and cleaning .10
16.3 Setting of wear formation conditions .10
16.3.1 General.10
16.3.2 Wear formation conditions for a dry environment .11
16.3.3 Wear formation conditions for a high-humidity environment .11
16.4 Wear formation .11
16.4.1 Start of wear formation on the thin film test specimen .11
16.4.2 Friction force measurement .11
16.5 E valuation of thin film test specimen surface and indenter ball surface after wear
formation .11
16.5.1 General.11
16.5.2 Measurement of wear track cross-section on thin film test specimen .11
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ISO/FDIS 23737:2021(E)

16.5.3 Evaluation of volume of worn portion on indenter ball surface .11
16.5.4 Investigations of morphology and elemental distribution maps .11
16.6 Calculation of friction coefficient .11
17 Precautions for summarization of test results .12
18 Test report .12
Annex A (informative) Example of reciprocating slide wear results and rotating slide wear
results .13
Annex B (informative) Method of holding polymer film or thin glass plate with a thickness
of < 200 µm in sliding wear formations .15
Annex C (informative) Effects of combining thin film materials and indenter materials
in sliding wear tests.17
Annex D (informative) Investigation of optimal load for indenter .22
Annex E (informative) Quantification of wear track cross-section area .24
Annex F (informative) Examples of investigations of morphology and elemental
distribution maps for wear tracks on thin films and worn sections of indenter balls .25
Bibliography .30
iv © ISO 2021 – All rights reserved

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ISO/FDIS 23737:2021(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 non­governmental, 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 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 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.
© ISO 2021 – All rights reserved v

---------------------- Page: 5 ----------------------
ISO/FDIS 23737:2021(E)

Introduction
Fine ceramic thin films are used in a wide variety of applications, such as sensors, actuators or other
micromechanical elements; display elements; memory elements; recording media; optical elements;
packaging films; and films and glass for building construction and vehicles. In the industrial application
of fine ceramic thin films, resistance to wear is an important index for evaluation. The resistance
to wear of fine ceramic thin films is greatly affected by environmental humidity and the humidity
history of the thin film. Fine ceramic thin films are also used in different humidity environments,
necessitating standards for the evaluation of wear resistance and the friction coefficient under a
wide humidity range. Standards published to date concerning wear resistance testing assume only
a temperature environment of 23 °C and a relative humidity of 50 %; the thickness of the thin films
subject to evaluation is also comparatively large, at several to 10 µm. These testing procedures are
inappropriate for evaluating the wear resistance of fine ceramic thin films that have a thickness of up
to approximately 1 µm and are applied for electronic and optical devices, because the wear resistance
for a smaller indentation load is affected by the relative humidity of the test environment, i.e. the
mechanisms employed in the wear test for fine ceramic thin films with a smaller indentation load are
strongly affected by the relative humidity of the test environment. Therefore, the wear test for fine
ceramic thin films should be performed under a regulated relative humidity condition. This document
provides measurement methods that facilitate the accurate evaluation of wear resistance for fine
ceramic thin films in dry and high-humidity environments, where such films have a thickness of up
to approximately 1 µm and are deposited on a thin substrate or an organic polymer film base. This
document has been enacted to facilitate industrial development through the prompt dissemination of
these measurement methods.
vi © ISO 2021 – All rights reserved

---------------------- Page: 6 ----------------------
FINAL DRAFT INTERNATIONAL STANDARD ISO/FDIS 23737:2021(E)
Fine ceramics (advanced ceramics, advanced technical
ceramics) — Methods for evaluating wear and friction
characteristics of fine ceramic thin films under dry and
humid conditions
1 Scope
This document specifies a method for testing the wear resistance and friction coefficient for fine
ceramic thin films in dry and high-humidity environments, where such films have a thickness of up to
approximately 1 µm and are deposited on a substrate or a base, including a thin substrate or a very thin
organic polymer film base.
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 13565­1, Geometrical Product Specifications (GPS) — Surface texture: Profile method; Surfaces having
stratified functional properties — Part 1: Filtering and general measurement conditions
ISO 13565­2, Geometrical Product Specifications (GPS) — Surface texture: Profile method; Surfaces having
stratified functional properties — Part 2: Height characterization using the linear material ratio curve
ISO 20507, Fine ceramics (advanced ceramics, advanced technical ceramics) — Vocabulary
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
wear
phenomenon leading to progressive loss or progressive displacement from the surface of a solid
material due to motion relative to a contacting body
3.2
frictional force
resistive force exerted on an opposing body when bodies in contact move or tend to slide against each
other
3.3
friction coefficient
dimensionless ratio of frictional force to the normal force applied
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3.4
wear test
test for evaluating friction and wear characteristics caused by sliding contact motion
Note 1 to entry: In a narrow sense, the term “wear test” implies the process of wear formation on the test
specimen due to a sliding motion; in a broad sense, it implies procedures such as specimen preparation, wear
formation, friction coefficient measurements, and evaluations of the wear track and the worn portion formed on
the counter material.
3.5
drying chamber
hermetically sealed vessel for eliminating moisture on a test specimen surface while the test specimen
remains held in a vacuum
3.6
relative humidity
ratio of water vapour partial pressure to saturated vapour pressure at a given temperature
3.7
dry air
air with a dew point of −60 °C or lower at an absolute pressure of 101,3 kPa
3.8
dry nitrogen
nitrogen with a dew point of −60 °C or lower at an absolute pressure of 101,3 kPa
4 Test specimens
Use fine ceramic thin films that have a thickness of up to approximately 1 µm and are deposited on
a silicon wafer, glass, organic polymer film or other such substrate or base. Provided that the test
specimens can be fitted on a wear testing apparatus as described in this document, the test specimen
dimensions and shape are of no concern. However, the thickness in the area where the wear formation
is performed shall be uniform.
5 Measurement principle
The wear properties of ceramic thin films are greatly affected by environmental humidity and the
humidity history of the thin film. Consequently, the wear resistance of a thin film test specimen should
be evaluated accurately by measuring wear of the thin film test specimen in dry and high-humidity
environments.
A reciprocating wear formation method or a rotating disc wear formation method shall be used as the
method for evaluating wear. Details of the principles pertaining to a reciprocating wear test method
are given in EN 1071:12. Details of the principles pertaining to a rotating disc wear test method are
given in ISO 20808 and EN 1071:13.
This document addresses both methods, i.e. a reciprocating wear test method and a rotating disc wear
test method. Annex A provides an example of results from testing carried out using a reciprocating
wear test method and a rotating disc wear test method.
6 Testing room environment
Measurements shall be carried out in a location subject to minimal changes in temperature and
humidity. Specifically, testing shall be carried out under the following environmental conditions:
a) testing room temperature: (23 ± 2) °C;
b) testing room relative humidity: 70 % or lower.
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NOTE If the temperature of the testing room is low, condensation can form on the wear evaluation apparatus.
7 Wear formation test apparatus
7.1 Reciprocating wear tester: The reciprocating wear tester shall consist of a test specimen
holder which retains a thin film test specimen, a drive apparatus which moves a thin film test specimen
reciprocally, a holder which retains and secures an indenter ball, a loading mechanism which applies a
constant load to the indenter ball, an equipment unit for detecting frictional force and a test environment
control sealing mechanism. Figure 1 shows a schematic of a test specimen holding system for a
reciprocating wear tester. Details concerning the reciprocal wear tester are given in EN 1071:12.
Key
1 indenter with a lateral force measurement system
2 test specimen
3 test specimen holder
4 wear track
Figure 1 — Schematic of a reciprocating wear tester (indicating the test specimen holding
system)
a) The test specimen holder shall move reciprocally within a horizontal plane and the deflection in
the direction of reciprocal motion shall be adjustable to 0,02 mm or less.
b) The drive apparatus shall allow for the setting of a predetermined sliding speed and changes in
the sliding speed due to variations in the frictional force shall be negligible. A reciprocating sliding
motion counter or equivalent device shall be included.
c) The indenter ball holder shall secure the indenter ball reliably against displacement by the frictional
force generated at the area of contact between the indenter ball and the test specimen, and shall
have high rigidity against induced stress.
d) The indenter ball loading mechanism shall apply and maintain a predetermined load either directly
or through a lever, and by means of a weight or a hydraulic or pressurized air system.
e) The frictional force detection equipment can be a load cell or a leaf spring strain measurement,
rotational torque measurement or other such measurement mechanism as desired, but its insertion
shall not affect the frictional conditions. The measurement precision for the frictional force shall
be within 1 % of the applied load. Use of an in situ linear wear measurement apparatus shall be
optional. If used, the apparatus shall have a depth resolution of less than 0,01 µm.
f) A sealing mechanism for controlling the test atmosphere shall be provided.
7.2 Rotating disc wear tester: The rotating disc wear tester shall consist of a test specimen holder
which retains a thin film test specimen, a drive apparatus which moves a thin film test specimen
rotationally, a holder which retains and secures an indenter ball, a loading mechanism which applies a
constant load to a thin film test specimen, a frictional force detection mechanism and a test environment
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control sealing mechanism. Figure 2 shows a schematic of a test specimen holding system for a rotating
disc wear tester. Details concerning the rotating disc wear tester are given in ISO 20808.
Key
1 indenter with a lateral force measurement system
2 test specimen
3 test specimen holder
4 wear track
Figure 2 — Schematic of a rotating disk wear tester (indicating the test specimen holding
system)
a) The rotating disc holder shall rotate within a horizontal or vertical plane, the deflection of the
rotational axis shall be adjustable to 0,02 mm or less, and the deflection in the direction of the
rotational axis at the area of contact shall be adjustable to 0,05 mm or less.
b) The drive apparatus shall allow for the setting of a disc rotation speed that provides a predetermined
sliding speed, and changes in the rotational speed due to variations in the frictional force shall be
negligible. A rotational speed counter or equivalent device shall be included.
c) The indenter ball holder shall secure the indenter ball reliably against rotation or displacement
by the frictional force generated at the area of contact between the indenter ball and the disc test
specimen, and shall have high rigidity against induced stress.
d) The indenter ball loading mechanism shall apply and maintain a predetermined load either directly
or through a lever, and by means of a weight or a hydraulic or pressurized air system.
e) The frictional force detection mechanism can be a load cell or a leaf spring strain measurement,
rotational torque measurement, or other such measurement mechanism as desired, but its
insertion shall not affect the frictional conditions. The measurement precision for the frictional
force shall be within 1 % of the applied load. Use of an in situ linear wear measurement apparatus
shall be optional. If used, the apparatus shall have a depth resolution of less than 0,01 µm.
f) A sealing mechanism for controlling the testing environment shall be provided.
7.3 Thermo-hygrostat chamber: The item used shall allow for the setting of relative humidity within
the range of 30 % to 90 % at a temperature of 23 °C. A metal or plastic tube shall be used to introduce air
of a predetermined temperature and humidity into the wear test chamber.
7.4 Dew point meter: The item shall be a capacitance (impedance) hygrometer (dew point meter) or
a chilled mirror dew point meter. Details are given in JIS Z 8806.
7.5 Stylus profilometer: A stylus surface roughness measurement apparatus as specified in
ISO 13565-1 and ISO 13565-2 or one with an equivalent or better precision shall be used.
7.6 Laser interferometric profilometer: The apparatus used shall make use of interference in parallel
light beams with an aligned wave surface to measure the surface profile of a test specimen surface, based
on the interference produced by a phase difference between light reflected from the test piece surface
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and light reflected from a reference surface serving as a standard. The apparatus used shall have a height
measurement resolution of approximately 10 nm at a magnification power of approximately 100× to
500×. A coherence scanning interferometry (CSI) system for three-dimensional mapping of surface
height is specified in ISO 25178-604.
7.7 Optical microscope: This apparatus shall magnify an object visually for observation using optical
lenses. The apparatus used shall have sufficient resolution at a magnification power of approximately
100× to 800×.
7.8 Scanning electron microscope: This microscope shall be equipped with a basic function for
forming a magnified image using an appropriate method, e.g. secondary electrons obtained from a test
specimen by two-dimensional scanning during irradiation of a test specimen with a tightly focused
electron beam. The apparatus used shall have sufficient resolution at an observational magnification
power of the order of 5 000×. For ceramic thin films, applying an electroconductive coating prior to the
observation is strongly recommended.
7.9 Energy dispersive X-ray spectroscopy: This instrument shall be equipped with an energy
dispersive X-ray (EDX) spectrometer to provide elemental identification by measuring the energy
of X-rays emitted from a specimen due to excitation by the primary electron beam. An elemental
distribution map can be acquired by combining the EDX signal with the position signal of the scanning
primary electron beam.
7.10 Drying chamber: Provided that the chamber can maintain an internal pressure of 4 kPa or lower
and a temperature of 130 °C or higher, its material, form and other details are not of concern.
7.11 Exhauster: A diaphragm pump or similar item shall be used. Provided that the item has an ultimate
pressure of 4 kPa or lower, its type shall not be of concern.
8 T
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