SIST EN ISO 14577-4:2017
(Main)Metallic materials - Instrumented indentation test for hardness and materials parameters - Part 4: Test method for metallic and non-metallic coatings (ISO 14577-4:2016)
Metallic materials - Instrumented indentation test for hardness and materials parameters - Part 4: Test method for metallic and non-metallic coatings (ISO 14577-4:2016)
This part of ISO 14577 specifies a method for testing coatings which is particularly suitable for testing
in the nano/micro range applicable to thin coatings. However, the application of this method of this part
of ISO 14577 is not needed if the indentation depth is such a small fraction of the coating thickness that
in any possible case a substrate influence can be neglected and the coating can be considered as a bulk
material. Limits for such cases are given.
This test method is limited to the examination of single layers when the indentation is carried out
normal to the test piece surface, but graded and multilayer coatings can also be measured in crosssection
if the thickness of the individual layers or gradations is greater than the spatial resolution of the
indentation process.
The test method is not limited to any particular type of material. Metallic and non-metallic coatings are
included in the scope of this part of ISO 14577. In this part of ISO 14577, the term coating is used to refer
to any solid layer with homogeneous properties different to that of a substrate it is connected to. The
method assumes that coating properties are constant with indentation depth. Composite coatings are
considered to be homogenous if the structure size is less than the indentation size.
The application of this part of ISO 14577 regarding measurement of indentation hardness is only
possible if the indenter is a pyramid or a cone with a radius of tip curvature small enough for plastic
deformation to occur within the coating. The hardness of visco-elastic materials or materials exhibiting
significant creep will be strongly affected by the time taken to perform the test.
NOTE 1 ISO 14577-1, ISO 14577-2 and ISO 14577-3 define usage of instrumented indentation testing of bulk
materials over all force and displacement ranges.
NOTE 2 The analysis used here does not make any allowances for pile-up or sink-in of indents. Use of Atomic
Force Microscopy (AFM) to assess the indent shape allows the determination of possible pile-up or sink-in of the
surface around the indent. These surface effects result in an under-estimate (pile-up) or over-estimate (sink-in) of
the contact area in the analysis and hence may influence the measured results. Pile-up generally occurs for fully
work-hardened materials. Pile-up of soft, ductile materials is more likely for thinner coatings due to the constraint
of the stresses in the zone of plastic deformation in the coating. It has been reported that the piled up material
results in an effective increase of the contact area for the determination of hardness, while the effect is less
pronounced for the determination of indentation modulus, since the piled up material behaves less rigidly.[1][2]
Metallische Werkstoffe - Instrumentierte Eindringprüfung zur Bestimmung der Härte und anderer Werkstoffparameter - Teil 4: Prüfverfahren für metallische und nichtmetalische Schichten (ISO 14577-4:2016)
Matériaux métalliques - Essai de pénétration instrumenté pour la détermination de la dureté et de paramètres des matériaux - Partie 4 : Méthode d'essai pour les revêtements métalliques et non métalliques (ISO 14577-4:2016)
ISO 14577-4:2016 spécifie une méthode d'essai pour les revêtements qui convient particulièrement pour soumettre à essai dans la plage nano-micro, applicable aux revêtements minces. Cependant l'application de la méthode de la présente partie de l'ISO 14577 n'est pas nécessaire si la profondeur de pénétration correspond à une fraction si petite de l'épaisseur du revêtement que, dans tous les cas possibles, une influence du substrat peut être négligée et le revêtement peut être considéré comme un matériau massif. Les limites de tels cas sont données.
La présente méthode d'essai est limitée à l'examen des couches simples lorsque l'empreinte est réalisée perpendiculairement à la surface de l'éprouvette, mais les revêtements avec une gradation ou comportant plusieurs couches peuvent également faire l'objet de mesures dans la section si l'épaisseur des couches individuelles ou des zones où la dureté évolue est supérieure à la résolution spatiale du processus de pénétration.
La méthode d'essai n'est pas limitée à un quelconque type particulier de matériau. Les revêtements métalliques et non métalliques sont inclus dans le domaine d'application de la présente partie de l'ISO 14577, le terme revêtement est utilisé pour désigner toute couche solide de caractéristiques homogènes différentes de celles du substrat à laquelle elle est reliée. La méthode suppose que les propriétés du revêtement sont constantes avec la profondeur de pénétration. Les revêtements composites sont considérés homogènes si la taille de la structure est inférieure à la taille de l'empreinte.
L'application de la présente partie de l'ISO 14577 en ce qui concerne la mesure de la dureté est possible seulement si le pénétrateur est une pyramide ou un cône avec un rayon de courbure de la pointe suffisamment petit pour que la déformation plastique se produise à l'intérieur du revêtement. La dureté des matériaux visco-élastiques ou des matériaux présentant un fluage significatif sera largement influencée par le temps utilisé pour réaliser l'essai.
Kovinski materiali - Preskus trdote in lastnosti materialov z instrumentirano metodo vtiskovanja - 4. del: Preskusna metoda za kovinske in nekovinske prevleke (ISO 14577-4:2016)
Ta de standarda ISO 14577 določa metodo za preskušanje prevlek, ki je še posebej primerna za preskušanje na nano/mikro ravni, ki se uporablja za tanke prevleke. Vendar uporaba te metode iz tega dela standarda ISO 14577 ni potrebna, če globina vtisa predstavlja tako majhen delež debeline prevleke, da je v vseh možnih primerih mogoče zanemariti vpliv podlage in se lahko prevleka obravnava kot razsuti material. Podane so omejitve za takšne primere.
Ta preskusna metoda je omejena na pregled posameznih slojev, ko je izveden
običajen vtis na površino preskušanca, vendar se lahko stopenjske in večslojne prevleke merijo tudi v preseku, če je debelina posameznih slojev ali prehodov večja od prostorske ločljivosti postopka vtiskovanja.
Preskusna metoda ni omejena na nobeno določeno vrsto materiala. Kovinske in nekovinske prevleke spadajo na področje uporabe tega dela standarda ISO 14577. V tem delu standarda ISO 14577 se izraz »prevleka« uporablja za vsak trden sloj s homogenimi lastnostmi, ki se razlikujejo od lastnosti podlage, s katero je spojen sloj. Metoda predpostavlja, da so lastnosti prevleke konstantne z globino vtisa. Kompozitne prevleke se štejejo za homogene, če je velikost strukture manjša od velikosti vtisa.
Uporaba tega dela standarda ISO 14577 o merjenju trdote vtisa je mogoča
le, če je vtisno telo piramida ali stolpec z dovolj majhnim polmerom ukrivljenosti konice, da pride do plastične deformacije prevleke. Na trdoto viskoelastičnih materialov ali materialov z visoko stopnjo lezenja močno vpliva čas, potreben za izvajanje preskusa.
OPOMBA 1: Standardi ISO 14577-1, ISO 14577-2 in ISO 14577-3 opredeljujejo uporabo preskušanja z instrumentiranim vtiskovanjem pri razsutih materialih v vseh razponih sile in premaknitev.
OPOMBA 2: Tukaj uporabljena analiza ne dovoljuje kopičenja ali udiranja vtisov. Uporaba atomske mikroskopije (AFM) za oceno oblike vtisa omogoča ugotavljanje možnega kopičenja ali udiranja površine okoli vtisa. Ti površinski vplivi povzročajo podcenitev (kopičenje) ali precenitev (udiranje) kontaktnega območja pri analizi, kar lahko vpliva na izmerjene rezultate. Kopičenje se običajno pojavi pri popolnoma deformacijsko utrjenih materialih. Kopičenje mehkih duktilnih materialov je verjetnejše pri tanjših prevlekah zaradi omejitev obremenitev v območju plastične deformacije prevleke. Poročila navajajo, da kopičenje materiala povzroči učinkovito povečanje kontaktnega območja za ugotavljanje trdote, medtem ko je učinek manj opazen pri ugotavljanju modula vtiskovanja, ker je nakopičen material manj trden.[1][2]
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN ISO 14577-4:2017
01-februar-2017
1DGRPHãþD
SIST EN ISO 14577-4:2008
Kovinski materiali - Preskus trdote in lastnosti materialov z instrumentirano
metodo vtiskovanja - 4. del: Preskusna metoda za kovinske in nekovinske prevleke
(ISO 14577-4:2016)
Metallic materials - Instrumented indentation test for hardness and materials parameters
- Part 4: Test method for metallic and non-metallic coatings (ISO 14577-4:2016)
Metallische Werkstoffe - Instrumentierte Eindringprüfung zur Bestimmung der Härte und
anderer Werkstoffparameter - Teil 4: Prüfverfahren für metallische und nichtmetalische
Schichten (ISO 14577-4:2016)
Matériaux métalliques - Essai de pénétration instrumenté pour la détermination de la
dureté et de paramètres des matériaux - Partie 4 : Méthode d'essai pour les revêtements
métalliques et non métalliques (ISO 14577-4:2016)
Ta slovenski standard je istoveten z: EN ISO 14577-4:2016
ICS:
77.040.10 Mehansko preskušanje kovin Mechanical testing of metals
SIST EN ISO 14577-4:2017 en,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN ISO 14577-4:2017
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SIST EN ISO 14577-4:2017
EN ISO 14577-4
EUROPEAN STANDARD
NORME EUROPÉENNE
November 2016
EUROPÄISCHE NORM
ICS 77.040.10 Supersedes EN ISO 14577-4:2007
English Version
Metallic materials - Instrumented indentation test for
hardness and materials parameters - Part 4: Test method
for metallic and non-metallic coatings (ISO 14577-4:2016)
Matériaux métalliques - Essai de pénétration Metallische Werkstoffe - Instrumentierte
instrumenté pour la détermination de la dureté et de Eindringprüfung zur Bestimmung der Härte und
paramètres des matériaux - Partie 4 : Méthode d'essai anderer Werkstoffparameter - Teil 4: Prüfverfahren für
pour les revêtements métalliques et non métalliques metallische und nichtmetalische Schichten (ISO 14577-
(ISO 14577-4:2016) 4:2016)
This European Standard was approved by CEN on 1 October 2016.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2016 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 14577-4:2016 E
worldwide for CEN national Members.
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SIST EN ISO 14577-4:2017
EN ISO 14577-4:2016 (E)
Contents Page
European foreword . 3
2
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SIST EN ISO 14577-4:2017
EN ISO 14577-4:2016 (E)
European foreword
This document (EN ISO 14577-4:2016) has been prepared by Technical Committee ISO/TC 164
"Mechanical testing of metals" in collaboration with Technical Committee ECISS/TC 101 “Test methods
for steel (other than chemical analysis)” the secretariat of which is held by AFNOR.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by May 2017, and conflicting national standards shall be
withdrawn at the latest by May 2017.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent
rights.
This document supersedes EN ISO 14577-4:2007.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Endorsement notice
The text of ISO 14577-4:2016 has been approved by CEN as EN ISO 14577-4:2016 without any
modification.
3
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SIST EN ISO 14577-4:2017
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SIST EN ISO 14577-4:2017
INTERNATIONAL ISO
STANDARD 14577-4
Second edition
2016-11-01
Metallic materials — Instrumented
indentation test for hardness and
materials parameters —
Part 4:
Test method for metallic and non-
metallic coatings
Matériaux métalliques — Essai de pénétration instrumenté pour la
détermination de la dureté et de paramètres des matériaux —
Partie 4: Méthode d’essai pour les revêtements métalliques et non
métalliques
Reference number
ISO 14577-4:2016(E)
©
ISO 2016
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SIST EN ISO 14577-4:2017
ISO 14577-4:2016(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2016, Published in Switzerland
All rights reserved. Unless otherwise specified, 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
Ch. de Blandonnet 8 • CP 401
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Tel. +41 22 749 01 11
Fax +41 22 749 09 47
copyright@iso.org
www.iso.org
ii © ISO 2016 – All rights reserved
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SIST EN ISO 14577-4:2017
ISO 14577-4:2016(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Symbols and designations . 2
4 Calibration and direct verification of testing machines . 2
5 Test pieces . 2
5.1 General . 2
5.2 Surface roughness . 2
5.3 Polishing . 3
5.4 Surface cleanliness . 3
6 Procedure. 4
6.1 Test conditions . 4
6.2 Measurement procedure . 5
6.2.1 General. 5
6.2.2 Force control experiments . 5
7 Data analysis and evaluation of results for indentation normal to the surface .5
7.1 General . 5
7.2 Coating indentation modulus . 6
7.3 Coating indentation hardness . 9
8 Uncertainty of the results .15
9 Test report .15
Annex A (informative) Contact point and fully elastic regime .16
Bibliography .18
© ISO 2016 – All rights reserved iii
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SIST EN ISO 14577-4:2017
ISO 14577-4:2016(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 on 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 the following URL: www.iso.org/iso/foreword.html.
The committee responsible for this document is ISO/TC 164, Mechanical testing of metals, Subcommittee
SC 3, Hardness testing.
This second edition cancels and replaces the first edition (ISO 14577-4:2007), which has been
technically revised.
ISO 14577 consists of the following parts, under the general title Metallic materials — Instrumented
indentation test for hardness and materials parameters:
— Part 1: Test method
— Part 2: Verification and calibration of testing machines
— Part 3: Calibration of reference blocks
— Part 4: Test method for metallic and non-metallic coatings
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SIST EN ISO 14577-4:2017
ISO 14577-4:2016(E)
Introduction
The elastic and plastic properties of a coating are critical factors determining the performance of the
coated product. Indeed, many coatings are specifically developed to provide wear resistance that is
usually conferred by their high hardness. Measurement of coating hardness is often used as a quality
control check. Young’s modulus becomes important when calculation of the stress in a coating is
required in the design of coated components. For example, the extent to which coated components can
withstand external applied forces is an important property in the capability of any coated system.
It is relatively straightforward to determine the hardness and indentation modulus of bulk materials
using instrumented indentation. However, when measurements are made normal to a coated surface,
depending on the force applied and the thickness of the coating, the substrate properties influence
the result.
The purpose of this part of ISO 14577 is to provide guidelines for conditions where a significant
influence of the substrate is detected and to provide possible analytical methods to enable the coating
properties to be extracted from the composite measurement. In some cases, the coating property can
be determined directly from measurements on a cross-section.
© ISO 2016 – All rights reserved v
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SIST EN ISO 14577-4:2017
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SIST EN ISO 14577-4:2017
INTERNATIONAL STANDARD ISO 14577-4:2016(E)
Metallic materials — Instrumented indentation test for
hardness and materials parameters —
Part 4:
Test method for metallic and non-metallic coatings
1 Scope
This part of ISO 14577 specifies a method for testing coatings which is particularly suitable for testing
in the nano/micro range applicable to thin coatings. However, the application of this method of this part
of ISO 14577 is not needed if the indentation depth is such a small fraction of the coating thickness that
in any possible case a substrate influence can be neglected and the coating can be considered as a bulk
material. Limits for such cases are given.
This test method is limited to the examination of single layers when the indentation is carried out
normal to the test piece surface, but graded and multilayer coatings can also be measured in cross-
section if the thickness of the individual layers or gradations is greater than the spatial resolution of the
indentation process.
The test method is not limited to any particular type of material. Metallic and non-metallic coatings are
included in the scope of this part of ISO 14577. In this part of ISO 14577, the term coating is used to refer
to any solid layer with homogeneous properties different to that of a substrate it is connected to. The
method assumes that coating properties are constant with indentation depth. Composite coatings are
considered to be homogenous if the structure size is less than the indentation size.
The application of this part of ISO 14577 regarding measurement of indentation hardness is only
possible if the indenter is a pyramid or a cone with a radius of tip curvature small enough for plastic
deformation to occur within the coating. The hardness of visco-elastic materials or materials exhibiting
significant creep will be strongly affected by the time taken to perform the test.
NOTE 1 ISO 14577-1, ISO 14577-2 and ISO 14577-3 define usage of instrumented indentation testing of bulk
materials over all force and displacement ranges.
NOTE 2 The analysis used here does not make any allowances for pile-up or sink-in of indents. Use of Atomic
Force Microscopy (AFM) to assess the indent shape allows the determination of possible pile-up or sink-in of the
surface around the indent. These surface effects result in an under-estimate (pile-up) or over-estimate (sink-in) of
the contact area in the analysis and hence may influence the measured results. Pile-up generally occurs for fully
work-hardened materials. Pile-up of soft, ductile materials is more likely for thinner coatings due to the constraint
of the stresses in the zone of plastic deformation in the coating. It has been reported that the piled up material
results in an effective increase of the contact area for the determination of hardness, while the effect is less
[1][2]
pronounced for the determination of indentation modulus, since the piled up material behaves less rigidly.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 14577-1:2015, Metallic materials — Instrumented indentation test for hardness and materials
parameters — Part 1: Test method
ISO 14577-2:2015, Metallic materials — Instrumented indentation test for hardness and materials
parameters — Part 2: Verification and calibration of testing machines
© ISO 2016 – All rights reserved 1
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SIST EN ISO 14577-4:2017
ISO 14577-4:2016(E)
ISO/IEC Guide 98-3, Uncertainty of measurement — Part 3: Guide to the expression of uncertainty in
measurement (GUM)
3 Symbols and designations
ISO 14577-1:2015, Table 1 provides a listing of symbols and their related designations. Additional
symbols and designations used in this international standard are included in Table 1.
Table 1 — Symbols and designations
Symbol Designation Unit
a Radius of contact mm
t Thickness of the coating mm
c
E Indentation modulus of the coating GPa
ITc
E * Indentation plane-strain modulus of the coating GPa
ITc
H Indentation hardness of the coating GPa
ITc
4 Calibration and direct verification of testing machines
The instrument shall be calibrated and directly verified according to the procedures set out in
ISO 14577-2:2015, Clause 4.
Indirect verification according to the procedure specified in ISO 14577-2:2015, Clause 5, using a
reference material, shall be made to ensure that a new direct verification is not needed and that no
damage or contamination has occurred to the indenter tip.
Indentation experiments may be performed with a variety of differently shaped indenters which should
be chosen to optimize the plastic and elastic deformation required for a given coating substrate system.
Typical indenter shapes are Vickers, Berkovich, conical, spherical and corner cube.
For the determination of coating plastic properties, pointed indenters are recommended. The thinner
the coating, the sharper the indenter should be. For the determination of coating elastic properties, any
geometry indenter may be used provided that its area function is known. If only the elastic properties
of the coating are required, indentations in the fully elastic regime are recommended (if possible) as
this avoids problems due to fracture, pile-up and high creep rates. A larger radius indenter tip or sphere
will allow fully elastic indentations over a larger force range than a smaller radius indenter. However,
too large a radius and surface effects will dominate the measurement uncertainties (roughness, surface
layers, etc.). Too small a radius and the maximum force or displacement before plastic deformation
begins will be very low. The optimum can be identified by preliminary experiments or modelling (see
Clause 7).
5 Test pieces
5.1 General
Generally, surface preparation of the test piece should be kept to a minimum and, if possible, the test
piece should be used in the as-received state if the surface condition conforms to the criteria given in
5.2, 5.3 and 5.4.
5.2 Surface roughness
Indentation into rough surfaces will lead to increased scatter in the results with decreasing indentation
depth (see ISO 14577-1:2015, Annex E). Clearly, when the roughness value, Ra, approaches the same
value as the indentation depth, the contact area will vary greatly from indent to indent depending on
its position relative to peaks and valleys at the surface. The final surface finish should be as smooth
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SIST EN ISO 14577-4:2017
ISO 14577-4:2016(E)
as available experience and facilities permit. The Ra value should be less than 5 % of the maximum
penetration depth whenever possible.
NOTE It has been shown that for a Berkovich indenter, the angle that the surface normal presents to the axis
[3]
of indentation has to be greater than 7° for significant errors to result. The important angle is that between
the indentation axis and the local surface normal at the point of contact. This angle may be significantly different
from the average surface plane for rough surfaces.
While Ra has been recommended as a practical and easily understood roughness parameter, this is an
average. Thus, single peaks and valleys may be greater than this as defined by the Rz value, although
the likelihood of encountering the maximum peak, for example, on the surface is small. Modelling to
[4][5]
investigate the roughness of the coating surface has concluded that there are two limiting situations
for any Ra value. When the “wavelength” of the roughness (in the plane of the coating surface) is much
greater than the indenter tip radius, the force-penetration response is determined by the local coating
surface curvature, but when the wavelength is much less than the tip radius, asperity contact occurs
and the effect is similar to having an additional lower modulus coating on the surface.
In cases where coatings are used in the as-received condition, random defects (such as nodular growths
or scratches) might be present. Where an indentation site imaging system is included in the testing
machine, it is recommended that “flat” areas away from these defects be selected for measurement.
The radius of the roughness profilometer probe should be less than the indenter radius. If the roughness
parameter Ra is determined with an AFM on a scan area, a scan area of 10 µm × 10 µm is recommended.
Some instruments are capable of scanning the indentation site before indentation. In this case, areas
with the required local slope and roughness may be selected for indentation in surfaces that might
otherwise, on average, be too rough.
5.3 Polishing
It should be appreciated that mechanical polishing of surfaces can result in a change in the work
hardening and/or the residual stress state of the surface and, consequently, the measured hardness.
For ceramics, this is less of a concern than for metals, although surface damage can occur. Grinding
and polishing shall be carried out such that any stress induced by the previous stage is removed by
the subsequent stage, and the final stage shall be with a grade of polishing medium appropriate to the
displacement scale being used in the test. If possible, electrochemical polishing should be used.
NOTE 1 Many coatings replicate the surface finish of the substrate. If it is acceptable to do so, surface
preparation problems can be reduced by ensuring that the substrate has an appropriate surface finish, thus
eliminating the need to prepare the surface of the coating. In some cases, however, changing the substrate surface
roughness may affect other coating properties; therefore, care should be taken when using this approach.
NOTE 2 In coatings, it is common to get relatively large residual stresses (e.g. arising from thermal expansion
coefficient mismatch between the coating and the substrate and/or stress induced by the coating deposition
process). Thus, a stress-free surface would not normally be expected. Furthermore, stress gradients in coatings
are not uncommon, so that removal of excessive material during a remedial surface preparation stage may result
in a significant departure from the original surface state.
NOTE 3 Polishing reduces the coating thickness and so the effects of the substrate will be enhanced when
indenting normal to the surface. Where the data analysis requires an accurate knowledge of the coating thickness
indented, polishing will require re-measurement of coating thickness. This again emphasizes the need to carry
out minimum preparation.
5.4 Surface cleanliness
Generally, provided the surface is free from obvious surface contamination, cleaning procedures should
be avoided. If cleaning is required, it shall be limited to methods that minimize damage, for example
— application of dry, oil-free, filtered gas stream,
© ISO 2016 – All rights reserved 3
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SIST EN ISO 14577-4:2017
ISO 14577-4:2016(E)
— application of subliming particle stream of CO (taking care not to depress the surface temperature
2
below the dew point), and
— rinsing with a solvent (which is chemically inert to the test piece) and then drying.
Ultrasonic methods are known to create or increase damage to coatings and should be used with
caution.
6 Procedure
6.1 Test conditions
6.1.1 The indenter geometry, maximum force and/or displacement and force displacement cycle (with
suitable hold periods) shall be selected by the operator to be appropriate to the coating to be measured
and the operating parameters of the instrument used (see Figure 1).
Indentation hardness values are only valid if plastic deformation has occurred so that there is a residual
indentation after force removal. Therefore, if both hardness and modulus are required from a single set
of indentations, then a small radius tip is required and a self-similar geometry.
NOTE 1 A typical “small” radius for hardness measurement is that of a Berkovich indenter (<250 nm). A typical
“large” radius for modulus measurement is <25 µm. In certain cases, a change of indenter can be avoided by force
selection. The range of elastic deformation can be estimated by the formulae in Annex A.
NOTE 2 An example of a simplified stress analysis is given in 7.3, Note 4.
6.1.2 Where multiple indentations normal to the surface or indentations in cross-section are planned,
each indent shall be positioned and separated according to ISO 14577-1:2015, 7.7.
NOTE Coatings can display a high degree of anisotropy, and thus the orientation of the indenter within the
plane and the direction of indentation (normal or cross-section) can significantly alter the measured value of the
hardness and sometimes the modulus.
6.1.3 The parameters of the instrumented indentation test are defined according to ISO 14577-
1:2015, 7.4.
The following parameters of coating/substrate influencing the measurement result should be
considered:
a) substrate hardness, Young’s modulus and Poisson’s ratio;
b) coating thickness;
c) surface roughness;
d) adhesion of the coating to the substrate (delamination of the coating should be avoided).
All these parameters should be kept constant if a direct comparison of force displacement curves is to
be made in order to detect a relative change in properties between two or more test pieces.
The time dependence of the material parameter being measured should be taken into account.
[6][7][8][9][10]
NOTE 1 Hardness and Young’s modulus values can be affected by adhesion.
NOTE 2 Variations in test piece parameters other than hardness or modulus can affect measurement of these
quantities. If the indentation
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