SIST EN ISO 14577-4:2008
Metallic materials - Instrumented indentation test for hardness and materials parameters - Part 4: Test method for metallic and non-metallic coatings (ISO 14577-4:2007)
Metallic materials - Instrumented indentation test for hardness and materials parameters - Part 4: Test method for metallic and non-metallic coatings (ISO 14577-4:2007)
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. 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, non-metallic and organic coatings are included in the scope of this part of ISO 14577. The application of this part of ISO 14577 regarding measurement of 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.
Metallische Werkstoffe - Instrumentierte Eindringprüfung zur Bestimmung der Härte und anderer Werkstoffparameter - Teil 4: Prüfverfahren für metallische und nichtmetalische Schichten (ISO 14577-4:2007)
In diesem Teil der ISO 14577 wird ein Verfahren zur Prüfung von Schichten festgelegt, das insbesondere zur Prüfung dünner Schichten im Nano- und Mikrobereich anwendbar ist.
Dieses Prüfverfahren ist auf die Prüfung von Einzelschichten beschränkt, falls der Eindruck senkrecht zur Oberfläche der zu prüfenden Probe erfolgt. Jedoch können auch Gradientenschichten und Mehrfachschichten im Querschnitt gemessen werden, falls die Dicke der einzelnen Schichten oder die Breite der Abstufung größer ist als die räumliche Auflösung des Eindringvorgangs.
Das Prüfverfahren ist nicht auf irgend einen Werkstofftyp beschränkt. Metallische, nichtmetallische und organische Schichten sind in den Anwendungsbereich dieses Teils von ISO 14577 einbezogen.
Die Anwendung dieses Teils der ISO 14577 ist bezüglich Härtemessung nur möglich, wenn der Eindringkörper eine Pyramide oder ein Kegel mit einem Spitzenradius, der klein genug ist, damit eine plastische Deformation in der Schicht auftritt. Die Härte viskoelastischer Werkstoffe oder von Werkstoffen, die ein bedeutendes Kriechen zeigen, wird erheblich von der Zeit zur Durchführung der Prüfung beeinflusst.
ANMERKUNG 1 ISO 14577-1, ISO 14577-2 und ISO 14577-3 legen die Durchführung der instrumentierten Eindringprüfung von unbeschichteten Werkstoffen in allen Kraft- und Wegbereichen fest.
ANMERKUNG 2 Die Anwendung dieses Teils der ISO 14577 ist nicht erforderlich, falls die Eindringtiefe so klein ist, dass in jedem möglichen Fall ein Substrateinfluss vernachlässigt werden kann und die Schicht als Volumenmaterial betrachtet werden kann. Grenzen für derartige Fälle werden gegeben.
ANMERKUNG 3 Die hier verwendete Auswertung lässt keinerlei Aufwölbung oder Einsinken des Eindrucks zu. Ein Atomkraftmikroskop (en: Atomic force Microscope) (AFM) sollte verwendet werden, um die Eindruckform zu erkennen und eine
Matériaux métalliques - Essai de pénétration instrumenté pour la détermination de la dureté et de parametres des matériaux - Partie 4: Méthode d'essai pour les revetements métalliques et non métalliques (ISO 14577-4:2007)
L'ISO 14577-4:2007 spécifie une méthode d'essai des revêtements qui convient particulièrement pour les essais dans les nano- et micro-plages, applicable aux revêtements minces.
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, non métalliques et organiques sont inclus dans le domaine d'application de l'ISO 14577-4:2007.
L'application de l'ISO 14577-4:2007 en ce qui concerne le mesurage 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 14577-4:2007)
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN ISO 14577-4:2008
01-april-2008
Kovinski materiali - Preskus trdote in lastnosti materialov z instrumentirano
metodo vtiskovanja - 4. del: Preskusna metoda za kovinske in nekovinske prevleke
(ISO 14577-4:2007)
Metallic materials - Instrumented indentation test for hardness and materials parameters
- Part 4: Test method for metallic and non-metallic coatings (ISO 14577-4:2007)
Metallische Werkstoffe - Instrumentierte Eindringprüfung zur Bestimmung der Härte und
anderer Werkstoffparameter - Teil 4: Prüfverfahren für metallische und nichtmetalische
Schichten (ISO 14577-4:2007)
Matériaux métalliques - Essai de pénétration instrumenté pour la détermination de la
dureté et de parametres des matériaux - Partie 4: Méthode d'essai pour les revetements
métalliques et non métalliques (ISO 14577-4:2007)
Ta slovenski standard je istoveten z: EN ISO 14577-4:2007
ICS:
77.040.10 Mehansko preskušanje kovin Mechanical testing of metals
SIST EN ISO 14577-4:2008 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
---------------------- Page: 1 ----------------------
EUROPEAN STANDARD
EN ISO 14577-4
NORME EUROPÉENNE
EUROPÄISCHE NORM
May 2007
ICS 77.040.10
English Version
Metallic materials - Instrumented indentation test for hardness
and materials parameters - Part 4: Test method for metallic and
non-metallic coatings (ISO 14577-4:2007)
Matériaux métalliques - Essai de pénétration instrumenté Metallische Werkstoffe - Instrumentierte Eindringprüfung
pour la détermination de la dureté et de paramètres des zur Bestimmung der Härte und anderer Werkstoffparameter
matériaux - Partie 4: Méthode d'essai pour les revêtements - Teil 4: Prüfverfahren für metallische und nichtmetalische
métalliques et non métalliques (ISO 14577-4:2007) Schichten (ISO 14577-4:2007)
This European Standard was approved by CEN on 13 April 2007.
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 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 Management Centre has the same status as the
official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36 B-1050 Brussels
© 2007 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 14577-4:2007: E
worldwide for CEN national Members.
---------------------- Page: 2 ----------------------
EN ISO 14577-4:2007 (E)
Foreword
This document (EN ISO 14577-4:2007) has been prepared by Technical Committee ISO/TC 164
"Mechanical testing of metals" in collaboration with Technical Committee ECISS/TC 1 "Steel -
Mechanical testing", 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 November 2007, and conflicting national
standards shall be withdrawn at the latest by November 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, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece,
Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United
Kingdom.
Endorsement notice
The text of ISO 14577-4:2007 has been approved by CEN as EN ISO 14577-4:2007 without any
modifications.
2
---------------------- Page: 3 ----------------------
INTERNATIONAL ISO
STANDARD 14577-4
First edition
2007-05-15
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 14577-4:2007(E)
©
ISO 2007
---------------------- Page: 4 ----------------------
ISO 14577-4:2007(E)
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.
COPYRIGHT PROTECTED DOCUMENT
© ISO 2007
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Published in Switzerland
ii © ISO 2007 – All rights reserved
---------------------- Page: 5 ----------------------
ISO 14577-4:2007(E)
Contents Page
Foreword. iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Symbols and designations . 2
4 Verification and calibration of testing machines. 2
5 Test pieces . 4
5.1 General. 4
5.2 Surface roughness . 4
5.3 Polishing. 5
5.4 Surface cleanliness . 5
5.5 Special requirements for paints and varnishes. 5
6 Procedure . 6
6.1 Test conditions . 6
6.2 Measurement procedure . 9
7 Data analysis and evaluation of results for indentation normal to the surface . 11
7.1 General. 11
7.2 Coating indentation modulus . 12
7.3 Coating indentation hardness . 13
8 Test report . 16
Annex A (normative) Frame compliance calibration procedure . 17
Annex B (normative) Contact point and fully elastic regime. 21
Bibliography . 23
© ISO 2007 – All rights reserved iii
---------------------- Page: 6 ----------------------
ISO 14577-4:2007(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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
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.
ISO 14577-4 was prepared by Technical Committee ISO/TC 164, Mechanical testing of metals, Subcommittee
SC 3, Hardness testing.
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
iv © ISO 2007 – All rights reserved
---------------------- Page: 7 ----------------------
ISO 14577-4:2007(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 there is no significant
influence of the substrate, and, where such influence is detected, 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 2007 – All rights reserved v
---------------------- Page: 8 ----------------------
INTERNATIONAL STANDARD ISO 14577-4:2007(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.
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, non-metallic and organic coatings are
included in the scope of this part of ISO 14577.
The application of this part of ISO 14577 regarding measurement of 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 application of the method of this part of ISO 14577 is not needed if the indentation depth is so small 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.
NOTE 3 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,
[1], [2]
since the piled up material behaves less rigidly .
2 Normative references
The following referenced documents are indispensable for the application 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 1514, Paints and varnishes — Standard panels for testing
ISO 2808, Paints and varnishes — Determination of film thickness
ISO 3270, Paints and varnishes and their raw materials — Temperatures and humidities for conditioning and
testing
© ISO 2007 – All rights reserved 1
---------------------- Page: 9 ----------------------
ISO 14577-4:2007(E)
ISO 4287, Geometrical Product Specifications (GPS) — Surface texture: Profile method — Terms, definitions
and surface texture parameters
ISO 14577-1:2002, Metallic materials — Instrumented indentation test for hardness and materials
parameters — Part 1: Test method
ISO 14577-2, Metallic materials — Instrumented indentation test for hardness and materials parameters —
Part 2: Verification and calibration of testing machines
ISO 14577-3, Metallic materials — Instrumented indentation test for hardness and materials parameters —
Part 3: Calibration of reference blocks
3 Symbols and designations
The symbols and designations in ISO 14577-1, ISO 14577-2 and ISO 14577-3 and in Table 1 apply.
Table 1 — Symbols and designations
Required in the
Symbol Designation Unit
test report
F Test force mN 9
2
A (h ) Projected area of contact of the indenter at distance h from the tip µm —
p c c
2 b
H Indentation hardness of the coating mN/µm 9
c
a
ν Poisson's ratio of the indenter — —
i
ν Poisson's ratio of the test piece — —
s
a Radius of contact area µm —
t Film thickness µm 9
c
C Frame compliance µm/mN 9
f
C Contact compliance (test piece) µm/mN —
s
C Total measured compliance µm/mN —
t
2 b
E Young's modulus mN/µm —
c 2
E * Plane strain indentation modulus of the coating mN/µm —
c
2 b
E * Plane strain indentation modulus mN/µm 9
IT
2 b
E Reduced modulus of the indentation contact mN/µm —
r
Ra Arithmetic mean deviation from the average height of the assessed µm
profile (see ISO 4287).
a
For diamond ν = 0,07.
i
2
b
1 mN/µm = 1 GPa.
c
E * = E * (at a/t = 0).
c IT c
4 Verification and calibration of testing machines
The instrument shall be calibrated according to the procedures set out in ISO 14577-2 and Annex A.
Indirect verification 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. If the results of these initial
indentations indicate the presence of contamination or damage, then the indenter should be cleaned using the
procedure recommended in ISO 14577-1 before further trial indents are made. After cleaning, inspection with
2 © ISO 2007 – All rights reserved
---------------------- Page: 10 ----------------------
ISO 14577-4:2007(E)
an optical microscope at a magnification of greater than 400× is recommended. Detection of sub-microscopic
damage or contamination is possible using appropriate microscopy of indents or the indenter. Where damage
is detected the indenter shall be replaced according to ISO 14577-2. The procedures for the determination of
the frame compliance C and the area function A (h ) calibration/verification shall be implemented before a
f p c
new indenter is used, see Figure 1.
NOTE A reference indenter is a calibrated indenter used infrequently and only for checking the instrument and test
indenter performance via indirect validation comparison.
Figure 1 — Flow chart of the decisions and actions to be taken in the case of
indirect verification failure
© ISO 2007 – All rights reserved 3
---------------------- Page: 11 ----------------------
ISO 14577-4:2007(E)
The instrumented indentation instrument shall achieve the required mechanical and thermal stability before
starting an indentation cycle, see 6.2.
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.
The test piece shall be mounted using the same methods as employed for determination/verification of the
instrument frame compliance, and shall be such that the test surface is normal to the axis of the indenter and
such that the local surface at the proposed indentation site is less than ± 5° from the perpendicular to the
indentation axis.
NOTE Possible methods for determining local slope include viewing with a high magnification microscope and
measuring the distance before the surface is out of focus. Knowledge of the depth of focus of the lens gives an estimate of
the local slope; also the perpendicularity and local slope can be checked in practice by imaging the indent if it is made by a
non-spherical indenter.
5.2 Surface roughness
Indentation into rough surfaces will lead to increased scatter in the results with decreasing indentation depth.
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 as available experience and facilities permit. The Ra value should
be less than 5 % of the maximum penetration depth whenever possible.
NOTE 1 It has been shown that for a Berkovich indenter, the angle that the surface normal presents to the axis of
[3]
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, see Note 2.
NOTE 2 While Ra has been recommended as a practical and easily understood roughness parameter, it should be
borne in mind that this is an average and 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
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.
NOTE 3 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.
4 © ISO 2007 – All rights reserved
---------------------- Page: 12 ----------------------
ISO 14577-4:2007(E)
The roughness profilometer probe radius should be comparable to the indenter radius. If the roughness
parameter Ra is determined with an AFM on a scan area, the size of this area should be agreed upon between
the customer and the measurement laboratory. 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 emphasises 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 minimise damage, for example
⎯ application of dry, oil-free, filtered gas stream,
⎯ application of subliming particle stream of CO (taking care not to depress the surface temperature below
2
the dew point), and
⎯ rinsing with a solvent (which is chemically inert to the test piece) and then drying.
If these methods fail and the surface is sufficiently robust, the surface may be wiped with a lintless tissue
soaked in solvent to remove trapped dust particles, then the surface shall be rinsed in a solvent as above.
Ultrasonic methods are known to create or increase damage to coatings and should be used with caution.
5.5 Special requirements for paints and varnishes
5.5.1 Substrate
Permitted substrates are steel, glass, aluminium, plastic and wood. Prepare the test panels as described in
5.5.2 and 5.5.3. Their surface should be free of visible damages. If samples are drawn from coated articles,
care should be taken that they are plane and will not be bent when being cut. The test panels should, when
under load, not yield or start to vibrate.
Small samples should be adequately supported to prevent deformation of the test sample during
measurement.
© ISO 2007 – All rights reserved 5
---------------------- Page: 13 ----------------------
ISO 14577-4:2007(E)
5.5.2 Preparation and coating of the substrate
The substrate for the test shall be prepared as described in ISO 1514 and shall be coated with the product or
system to be tested according to the procedure laid down. Coating thickness should be more than ten times
the indentation depth when values specific for the material should be determined.
5.5.3 Drying and conditioning of the test coating
The coated test panel should be dried, hardened and aged for the established time and under the established
conditions, with at least 24 h storage under standard conditions as described in ISO 3270. Coating thickness
should be determined according to one of the methods specified in ISO 2808.
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 2.
Hardness values are only valid if plastic deformation has occurred and there is a residual indentation after
force removal.
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 formulas of Annex B.
NOTE 2 An example o
...
Questions, Comments and Discussion
Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.