Metallic materials - Instrumented indentation test for hardness and materials parameters - Part 1: Test method (ISO 14577-1:2015)

ISO 14577-1:2015 specifies the method of instrumented indentation test for determination of hardness and other materials parameters for the following three ranges: macro range: 2 N ≤ F ≤ 30 kN; micro range: 2 N > F; h > 0,2 µm; and nano range: h ≤ 0,2 µm.
For the nano range, the mechanical deformation strongly depends on the real shape of indenter tip and the calculated material parameters are significantly influenced by the contact area function of the indenter used in the testing machine. Therefore, careful calibration of both instrument and indenter shape is required in order to achieve an acceptable reproducibility of the materials parameters determined with different machines.
The macro and micro ranges are distinguished by the test forces in relation to the indentation depth.
Attention is drawn to the fact that the micro range has an upper limit given by the test force (2 N) and a lower limit given by the indentation depth of 0,2 µm.
The determination of hardness and other material parameters is given in Annex A.
At high contact pressures, damage to the indenter is possible. For this reason in the macro range, hardmetal indenters are often used. For test pieces with very high hardness and modulus of elasticity, permanent indenter deformation can occur and can be detected using suitable reference materials. It is necessary that its influence on the test result be taken into account.
This test method can also be applied to thin metallic and non-metallic coatings and non-metallic materials. In this case, it is recommended that the specifications in the relevant standards be taken into account (see also 6.3 and ISO 14577‑4).

Metallische Werkstoffe - Instrumentierte Eindringprüfung zur Bestimmung der Härte und anderer Werkstoffparameter - Teil 1: Prüfverfahren (ISO 14577-1:2015)

Dieser Teil von ISO 14577 legt das Verfahren für die instrumentierte Eindringprüfung zur Bestimmung der Härte und anderer Werkstoffparameter für die drei folgenden Bereiche fest:
 Makrobereich: 2 ≤ F ≤ 30 kN;
 Mikrobereich: 2 N > F; h > 0,2 μm;
 Nanobereich: h ≤ 0,2 μm.
ANMERKUNG 1 Im Nanobereich hängt die mechanische Verformung stark von der realen Geometrie der Eindringkörperspitze ab und die berechneten Werkstoffparameter werden wesentlich durch die Flächenfunktion des in der Prüfmaschine verwendeten Eindringkörpers beeinflusst. Deshalb ist eine sorgfältige Kalibrierung der Prüfmaschine und der Eindringkörpergeometrie erforderlich, um eine akzeptable Wiederholpräzision der Werkstoffparameter, die mit verschiedenen Prüfmaschinen bestimmt wurden, zu erhalten.
Der Mikro- und Makrobereich unterscheiden sich durch die die Eindringtiefe bewirkenden Prüfkräfte.
Es ist zu beachten, dass der Mikrobereich nach oben durch die Prüfkraft (2 N) und nach unten durch eine Eindringtiefe von 0,2 μm begrenzt ist.
Für die Bestimmung der Härte und der anderen Werkstoffparameter siehe Anhang A.
Bei hohem Kontaktdruck sind Beschädigungen des Eindringkörpers möglich. Aus diesem Grunde werden im Makrobereich häufig Eindringkörper aus Hartmetall verwendet. Bei Proben mit sehr hoher Härte und sehr großem Elastizitätsmodul kann eine bleibende Verformung des Eindringkörpers auftreten, welche mit Hilfe geeigneter Referenzwerkstoffe nachgewiesen werden kann und es ist notwendig, den entsprechenden Einfluss auf das Prüfergebnis zu berücksichtigen.
ANMERKUNG 2 Dieses Prüfverfahren kann auch zur Prüfung dünner metallischer und nichtmetallischer Beschichtungen und von Nichtmetallen verwendet werden. In diesem Fall wird empfohlen, dass die in den entsprechenden Normen enthaltenen Festlegungen beachtet werden (siehe auch 6.3 in diesem Teil von ISO 14577 und ISO 14577-4).

Matériaux métalliques - Essai de pénétration instrumenté pour la détermination de la dureté et de paramètres des matériaux - Partie 1 : Méthode d'essai (ISO 14577-1:2015)

L'ISO 14577-1:2015 spécifie la méthode d'essai de pénétration instrumenté pour la détermination de la dureté et d'autres paramètres de matériaux pour les trois plages suivantes : Macro-intervalle, 2 kN ≤ F ≤ 30 kN ; Micro-intervalle, 2 > F ; h > 0,2 µm ; et Nano-intervalle, h ≤ 0,2 µm.
Pour la nano-intervalle, la déformation mécanique dépend fortement de la forme réelle de la pointe du pénétrateur, et les paramètres de matériaux calculés sont influencés de manière significative par la fonction d'aire de contact du pénétrateur utilisé sur la machine d'essai. En conséquence, un étalonnage soigné de l'instrument et de la forme du pénétrateur est nécessaire pour obtenir une reproductibilité acceptable des paramètres de matériaux déterminés avec différentes machines.
Les macro- et micro-intervalles se distinguent par les forces d'essai en relation avec la profondeur d'empreinte.
L'attention est attirée sur le fait que le micro-intervalle a une limite supérieure donnée par la force d'essai (2 N) et une limite inférieure donnée par la profondeur d'empreinte de 0,2 µm.
La détermination de la dureté et d'autres paramètres de matériaux est donnée dans l'Annexe A.
L'endommagement du pénétrateur est possible pour les pressions de contact élevées. Pour cette raison, des pénétrateurs en carbure sont souvent utilisés pour la macro-intervalle. Pour les éprouvettes à dureté et module d'élasticité élevés, il convient de tenir compte de l'influence de la déformation du pénétrateur sur le résultat d'essai.
Cette méthode d'essai est également applicable à des revêtements métalliques et non métalliques minces et à des matériaux non métalliques. Dans ce cas, il convient de prendre en compte les spécifications données dans les normes applicables (voir également 6.3 de la présente norme et l'ISO 14577‑4).

Kovinski materiali - Instrumentirano vtiskanje pri preskušanju trdote in drugih lastnosti materialov - 1. del: Preskusna metoda (ISO 14577-1:2015)

Ta del standarda ISO 14577 določa metodo za preskus z instrumentiranim vtiskanjem za ugotavljanje
trdote in drugih lastnosti materialov za naslednje tri ravni:
– makro raven: 2 N ≤ F ≤ 30 kN;
– mikro raven: 2 N > F; h > 0,2 μm;
– nano raven: h ≤ 0,2 μm.
Za nano raven je mehansko preoblikovanje zelo odvisno od dejanske oblike preskusne konice, pri čemer na izračunane lastnosti materialov znatno vpliva funkcija kontaktnega območja preskusne konice, ki se uporabi za preskusni stroj. Zato je treba skrbno kalibrirati instrument in obliko preskusne konice, da se doseže sprejemljiva ponovljivost lastnosti materialov, ki se ugotovijo z različnimi stroji.
Makro raven in mikro raven se razlikujeta glede na preskusne sile pri globini vtisa. Upoštevati je treba tudi, da ima mikro raven zgornjo mejo, podano s preskusno silo (2 N), in spodnjo mejo, podano z globino vtisa 0,2 μm.
Ugotavljanje trdote in drugih lastnosti materialov je podano v dodatku A. Ob visokih kontaktnih silah se lahko preskusna konica poškoduje. Zato se za makro raven pogosto uporabljajo preskusne konice iz trdih kovin. Pri preskušancih zelo velike trdote in modulov elastičnosti lahko pride do trajnega preoblikovanja preskusne konice, kar je mogoče ugotoviti s primernimi referenčnimi materiali. Obvezno je treba upoštevati vpliv, ki ga ima to na rezultate preskusa.
To preskusno metodo je mogoče uporabiti tudi za tanke kovinske in nekovinske prevleke ter nekovinske materiale. V tem primeru je priporočeno, da upoštevate specifikacije v ustreznih standardih (glej tudi 6.3 in ISO 14577-4).

General Information

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Publication Date
30-Oct-2015
Withdrawal Date
30-Jan-2016
Current Stage
6060 - Definitive text made available (DAV) - Publishing
Start Date
29-Jul-2015
Completion Date
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SLOVENSKI STANDARD
SIST EN ISO 14577-1:2015
01-oktober-2015
1DGRPHãþD
SIST EN ISO 14577-1:2004
Kovinski materiali - Instrumentirano vtiskanje pri preskušanju trdote in drugih
lastnosti materialov - 1. del: Preskusna metoda (ISO 14577-1:2015)

Metallic materials - Instrumented indentation test for hardness and materials parameters

- Part 1: Test method (ISO 14577-1:2015)

Metallische Werkstoffe - Instrumentierte Eindringprüfung zur Bestimmung der Härte und

anderer Werkstoffparameter - Teil 1: Prüfverfahren (ISO 14577-1:2015)

Matériaux métalliques - Essai de pénétration instrumenté pour la détermination de la

dureté et de paramètres des matériaux - Partie 1: Méthode d'essai (ISO 14577-1:2015)

Ta slovenski standard je istoveten z: EN ISO 14577-1:2015
ICS:
77.040.10 Mehansko preskušanje kovin Mechanical testing of metals
SIST EN ISO 14577-1:2015 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 14577-1:2015
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SIST EN ISO 14577-1:2015
EUROPEAN STANDARD
EN ISO 14577-1
NORME EUROPÉENNE
EUROPÄISCHE NORM
July 2015
ICS 77.040.10 Supersedes EN ISO 14577-1:2002
English Version
Metallic materials - Instrumented indentation test for hardness
and materials parameters - Part 1: Test method (ISO 14577-
1:2015)

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 1 : Méthode d'essai (ISO 14577-1:2015) - Teil 1: Prüfverfahren (ISO 14577-1:2015)

This European Standard was approved by CEN on 16 April 2015.

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

© 2015 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 14577-1:2015 E

worldwide for CEN national Members.
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SIST EN ISO 14577-1:2015
EN ISO 14577-1:2015 (E)
Contents
Page

European foreword ..................................................................................................................................3

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SIST EN ISO 14577-1:2015
EN ISO 14577-1:2015 (E)
European foreword

This document (EN ISO 14577-1:2015) 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 January 2016, and conflicting national standards shall be withdrawn at

the latest by January 2016.

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 14577-1:2002.

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 14577-1:2015 has been approved by CEN as EN ISO 14577-1:2015 without any modification.

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SIST EN ISO 14577-1:2015
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SIST EN ISO 14577-1:2015
INTERNATIONAL ISO
STANDARD 14577-1
Second edition
2015-07-15
Metallic materials — Instrumented
indentation test for hardness and
materials parameters —
Part 1:
Test method
Matériaux métalliques — Essai de pénétration instrumenté pour la
détermination de la dureté et de paramètres des matériaux —
Partie 1: Méthode d’essai
Reference number
ISO 14577-1:2015(E)
ISO 2015
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SIST EN ISO 14577-1:2015
ISO 14577-1:2015(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2015, 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
CH-1214 Vernier, Geneva, Switzerland
Tel. +41 22 749 01 11
Fax +41 22 749 09 47
copyright@iso.org
www.iso.org
ii © ISO 2015 – All rights reserved
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SIST EN ISO 14577-1:2015
ISO 14577-1:2015(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction ..................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Symbols and designations .......................................................................................................................................................................... 2

4 Principle ........................................................................................................................................................................................................................ 4

5 Testing machine .................................................................................................................................................................................................... 4

6 Test piece ...................................................................................................................................................................................................................... 5

7 Procedure..................................................................................................................................................................................................................... 5

8 Uncertainty of the results ............................................................................................................................................................................ 8

9 Test report ................................................................................................................................................................................................................... 9

Annex A (normative) Materials parameters determined from the force/indentation depth

data set .........................................................................................................................................................................................................................11

Annex B (informative) Types of control use for the indentation process ...................................................................24

Annex C (normative) Machine compliance and indenter area function .......................................................................25

Annex D (informative) Notes on diamond indenters ........................................................................................................................27

Annex E (normative) Influence of the test piece surface roughness on the accuracy of

the results .................................................................................................................................................................................................................28

Annex F (informative) Correlation of indentation hardness H to Vickers hardness ...................................29

Annex G (normative) Drift and creep rate determination ..........................................................................................................31

Annex H (informative) Estimation of uncertainty of the calculated values of hardness and

materials parameters ...................................................................................................................................................................................33

Annex I (normative) Calculation of radial displacement correction ...............................................................................43

Bibliography .............................................................................................................................................................................................................................45

© ISO 2015 – All rights reserved iii
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SIST EN ISO 14577-1:2015
ISO 14577-1:2015(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 WTO principles in the Technical Barriers

to Trade (TBT) see the following URL: Foreword - Supplementary information

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 14577-1:2002), 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
iv © ISO 2015 – All rights reserved
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SIST EN ISO 14577-1:2015
ISO 14577-1:2015(E)
Introduction

Hardness has typically been defined as the resistance of a material to permanent penetration by

another harder material. The results obtained when performing Rockwell, Vickers, and Brinell tests are

determined after the test force has been removed. Therefore, the effect of elastic deformation under the

indenter has been ignored.

ISO 14577 (all parts) has been prepared to enable the user to evaluate the indentation of materials by

considering both the force and displacement during plastic and elastic deformation. By monitoring the

complete cycle of increasing and removal of the test force, hardness values equivalent to traditional

hardness values can be determined. More significantly, additional properties of the material, such as

its indentation modulus and elasto-plastic hardness, can also be determined. All these values can be

calculated without the need to measure the indent optically. Furthermore, by a variety of techniques, the

instrumented indentation test allows to record hardness and modulus depth profiles within a, probably

complex, indentation cycle.

ISO 14577 (all parts) has been written to allow a wide variety of post-test data analysis.

© ISO 2015 – All rights reserved v
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SIST EN ISO 14577-1:2015
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SIST EN ISO 14577-1:2015
INTERNATIONAL STANDARD ISO 14577-1:2015(E)
Metallic materials — Instrumented indentation test for
hardness and materials parameters —
Part 1:
Test method
1 Scope

This part of ISO 14577 specifies the method of instrumented indentation test for determination of

hardness and other materials parameters for the following three ranges:
— macro range: 2 N ≤ F ≤ 30 kN;
— micro range: 2 N > F; h > 0,2 µm;
— nano range: h ≤ 0,2 µm.

For the nano range, the mechanical deformation strongly depends on the real shape of indenter tip and the

calculated material parameters are significantly influenced by the contact area function of the indenter

used in the testing machine. Therefore, careful calibration of both instrument and indenter shape is

required in order to achieve an acceptable reproducibility of the materials parameters determined with

different machines.

The macro and micro ranges are distinguished by the test forces in relation to the indentation depth.

Attention is drawn to the fact that the micro range has an upper limit given by the test force (2 N) and a

lower limit given by the indentation depth of 0,2 µm.
The determination of hardness and other material parameters is given in Annex A.

At high contact pressures, damage to the indenter is possible. For this reason in the macro range,

hardmetal indenters are often used. For test pieces with very high hardness and modulus of elasticity,

permanent indenter deformation can occur and can be detected using suitable reference materials. It is

necessary that its influence on the test result be taken into account.

This test method can also be applied to thin metallic and non-metallic coatings and non-metallic

materials. In this case, it is recommended that the specifications in the relevant standards be taken into

account (see also 6.3 and ISO 14577-4).
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 14577-2:2015, Metallic materials — Instrumented indentation test for hardness and materials

parameters — Part 2: Verification and calibration of testing machines

ISO/IEC Guide 98-3:2008, Uncertainty of measurement — Part 3: Guide to the expression of uncertainty in

measurement (GUM:1995)
© ISO 2015 – All rights reserved 1
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SIST EN ISO 14577-1:2015
ISO 14577-1:2015(E)
3 Symbols and designations

For the purposes of this document, the symbols and designations in Table 1 shall be applied (see also

Figure 1 and Figure 2).
Table 1 — Symbols and designations
Symbol Designation Unit
A (h ) Projected area of contact of the indenter at distance h from the tip mm
p c c
A (h) Surface area of the indenter at distance h from the tip mm
C Indentation creep %

Total measured compliance of the contact (dh/dF tangent to the force removal nm/mN

curve at maximum test force)
C Instrument compliance nm/mN
C Compliance of the contact after correction for machine compliance nm/mN
E Indentation modulus of the test piece GPa
Reduced plane strain modulus of the contact (combination of test piece and GPa
indenter plane strain moduli)
F Test force N
F Maximum test force N
max
h Indentation depth under applied test force mm
h Depth of the contact of the indenter with the test piece at F mm
c max
h Maximum indentation depth at F mm
max max
h Permanent indentation depth after removal of the test force mm
Point of intersection of the tangent c to curve b at F with the indentation mm
max
depth-axis as identified on Figure 1
H Indentation hardness GPa
HM Martens hardness GPa
Martens hardness, determined from the slope of the increasing GPa
force/indentation depth curve
GPa
diff Martens hardness, determined from the first derivative of h vs F
ν Poisson’s ratio of the test piece
r Radius of spherical indenter mm
R Indentation relaxation %
W Elastic reverse deformation work of indentation N⋅m
elast
W Total mechanical work of indentation N⋅m
total
Cone semi-angle or angle of facet to the indentation axis for pyramidal °
indenters
Maximum angle between the contact surface and the indenter for calculation °
of radial displacement
η Ratio W /W %
IT elast total

NOTE 1 To avoid very long numbers, the use of multiples or sub-multiples of the units is permitted.

2 2
NOTE 2 The continued use of the unit N/mm is allowed. 1 MPa = 1 N/mm .
2 © ISO 2015 – All rights reserved
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SIST EN ISO 14577-1:2015
ISO 14577-1:2015(E)
Key
a application of the test force
b removal of the test force
c tangent to curve b at F
max
Figure 1 — Schematic representation of the test procedure
Key
a indenter

b surface of residual plastic indentation in a test piece that has a “perfectly plastic” response

c surface of test piece at maximum indentation depth and test force
θ maximum angle between the test piece surface and the indenter
Figure 2 — Schematic representation of the cross section of indentation
in the case of material “sink-in”
© ISO 2015 – All rights reserved 3
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SIST EN ISO 14577-1:2015
ISO 14577-1:2015(E)
4 Principle

Continuous recording of the force and the depth of indentation permits the determination of hardness

and material properties (see Figure 1 and Figure 2). An indenter consisting of a material harder than the

material under test shall be used. The following shapes and materials can be used:

a) diamond indenter shaped as an orthogonal pyramid with a square base and with an angle α = 68°

between the axis of the diamond pyramid and one of the faces (Vickers pyramid; see Figure A.1);

b) diamond pyramid with triangular base (e.g. modified Berkovich pyramid with an angle α = 65,27°

between the axis of the diamond pyramid and one of the faces; see Figure A.1);

c) hardmetal ball (especially for the determination of the elastic behaviour of materials);

d) diamond spherical tipped conical indenter.

This part of ISO 14577 does not preclude the use of other indenter geometries; however, care should be taken

in interpreting the results obtained with such indenters. Other materials like sapphire can also be used.

NOTE Due to the crystal structure of diamond, indenters that are intended to be spherical are often

polyhedrons and do not have an ideal spherical shape.

The test procedure can either be force-controlled or displacement-controlled. The test force, F, the

corresponding indentation depth, h, and time are recorded during the whole test procedure. The result

of the test is the data set of the test force and the relevant indentation depths as a function of time (see

Figure 1 and Annex B).

For a reproducible determination of the force and corresponding indentation depth, the zero point for

the force/indentation depth measurement shall be assigned individually for each test (see 7.3).

Where time-dependent effects are being measured

— using the force-controlled method, the test force is kept constant over a specified period and the

change of the indentation depth is measured as a function of the holding time of the test force (see

Figures A.3 and B.1), and

— using the indentation depth controlled method, the indentation depth is kept constant over a

specified period and the change of the test force is measured as a function of the holding time of the

indentation depth (see Figures A.4 and B.2).

The two kinds of control mentioned give essentially different results in the segment b of the curves in

Figure B.1 a) and Figure B.2 b) or in Figure B.1 b) and Figure B.2 a).
5 Testing machine

5.1 The testing machine shall have the capability of applying predetermined test forces or displacements

within the required scope and shall fulfil the requirements of ISO 14577-2.

5.2 The testing machine shall have the capability of measuring and reporting applied force, indentation

displacement and time throughout the testing cycle.

5.3 The testing machine shall have the capability of compensating for the machine compliance and of

utilizing the appropriate indenter area function (see Annex C and ISO 14577-2:2015, 4.5 and 4.6).

5.4 Indenters for use with testing machines can have various shapes, as specified in ISO 14577-2 (for

further information on diamond indenters, see Annex D).

5.5 The testing machine shall operate at a temperature within the permissible range specified in 7.1

and shall maintain its calibration within the limits specified in ISO 14577-2:2015, Clause 4.

4 © ISO 2015 – All rights reserved
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SIST EN ISO 14577-1:2015
ISO 14577-1:2015(E)
6 Test piece

6.1 The test shall be carried out on a region of the test surface that allows the determination of the

force/indentation depth curve for the respective indentation range within the required uncertainty. The

contact area shall be free of fluids or lubricants except where this is essential for the performance of the

test, in which case, this shall be described in detail in the test report. Care shall be taken that extraneous

matter (e.g. dust particles) is not incorporated into the contact.

Generally, provided the surface is free from obvious surface contamination, cleaning procedures should

be avoided. If cleaning is required, it shall be limited to the following methods to minimize damage:

— application of a dry, oil-free, filtered gas stream;

— application of a subliming particle stream of CO (but keeping the surface temperature above

the dew point);

— rinsing with a solvent (which is chemically inert to the test piece) and then setting it to dry.

If these methods fail and the surface is sufficiently robust, wipe the surface with a lint-free tissue soaked

in solvent to remove trapped dust particles, after which, the surface shall be rinsed in a solvent as above.

Ultrasonic methods are known to create or increase damage to surfaces and coatings and should only

be used with caution.

For an explanation concerning the influence of the test piece roughness on the uncertainty of the results,

see Annex E. Surface finish has a significant influence on the test results.

The test surfaces shall be normal to the test force direction. It is recommended that the test surface tilt

is less than 1°. Tilt should be included in the uncertainty calculation.

6.2 Preparation of the test surface shall be carried out in such a way that any alteration of the surface

hardness and/or surface residual stress (e.g. due to heat or cold-working) is minimized.

Due to the small indentation depths in the micro and nano range, special precautions shall be taken during

the test piece preparation. A polishing process that is suitable for the particular materials shall be used.

6.3 The test piece thickness shall be large enough (or indentation depth small enough) such that the

test result is not influenced by the test piece support. The test piece thickness should be at least 10 × the

indentation depth or 3 × the indentation diameter (see 7.7), whichever is greater.

When testing coatings, the coating thickness should be considered as the test piece thickness. For testing

coatings, see ISO 14577-4.

NOTE The above are empirically based limits. The exact limits of influence of support on test piece depend on

the geometry of the indenter used and the materials properties of the test piece and support.

7 Procedure

7.1 The temperature of the test shall be recorded. Typically, tests are carried out in the range of ambient

temperatures between 10 °C and 35 °C.

The temperature stability during a test is more important than the actual test temperature. Any

calibration correction applied shall be reported along with the additional calibration uncertainty.

It is recommended that tests, particularly in the nano and micro ranges, be performed in controlled

conditions, in the range (23 ± 5) °C and (45 ± 10) % relative humidity.
© ISO 2015 – All rights reserved 5
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SIST EN ISO 14577-1:2015
ISO 14577-1:2015(E)

The individual tests, however, shall be carried out at stable temperature conditions because of the

requirement of high depth measuring accuracy. This means that
— the test pieces shall have reached the ambient temperature before testing,

— the testing machine shall have reached a stable working temperature (operating manual should

be consulted),

— the ambient, instrument, and test temperature shall be within the range for which the machine

calibration is valid, and

— other external influences causing temperature changes during individual test have been controlled.

To minimize thermally induced displacement drift, the temperature of the testing machine shall

be adequately maintained over the time period of one testing cycle, or a displacement drift shall be

measured and corrected. A decision tree to assist in estimating the drift during the experiment is shown

in Figure 3. If the drift rate is significant, the displacement data shall be corrected by measuring the

drift rate during a hold at an applied force as close to zero force as is practicable or during a hold at a

suitable place in the force removal curve (see ISO 14577-2:2015, Annex G and 4.3.3). If a contact in the

fully elastic regime can be obtained, a hold at initial contact is preferred. In this way, material influences

(creep, visco-plasticity, cracking) can be minimized. The uncertainty due to the drift, or in the drift

correction used, shall be reported.

NOTE To determine the drift of surface referenced instruments, elastic contact between the reference and

the surface is sufficient; contact of the indenter with the surface is not required and is not recommended.

Figure 3 — Decision tree to assist in estimating thermal drift using a constant force hold period

7.2 The test piece shall be firmly supported such that there is no significant increase in the testing

machine compliance. The test piece shall either be placed on a support that is rigid in the direction of

indentation or be fixed in a suitable test piece holder. The contact surfaces between test piece support

and test piece holder shall be free from extraneous matter, which can increase the compliance (reduce the

stiffness) of the test piece support.
6 © ISO 2015 – All rights reserved
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SIST EN ISO 14577-1:2015
ISO 14577-1:2015(E)

NOTE If the sample is supported by materials or mounting methods other than those used when determining

the machine compliance, then the different elastic response of these materials and mounting metho

...

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