ISO 14705:2016
(Main)Fine ceramics (advanced ceramics, advanced technical ceramics) — Test method for hardness of monolithic ceramics at room temperature
Fine ceramics (advanced ceramics, advanced technical ceramics) — Test method for hardness of monolithic ceramics at room temperature
ISO 14705:2016 specifies a test method for determining the Vickers and Knoop hardness of monolithic fine ceramics at room temperature.
Céramiques techniques — Méthode d'essai de dureté des céramiques monolithiques à température ambiante
Le présent document spécifie une méthode d'essai pour déterminer la dureté Vickers et Knoop des céramiques techniques monolithiques à température ambiante.
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Standards Content (Sample)
DRAFT INTERNATIONAL STANDARD
ISO/DIS 14705
ISO/TC 206 Secretariat: JISC
Voting begins on: Voting terminates on:
2016-01-12 2016-04-12
Fine ceramics (advanced ceramics, advanced technical
ceramics) — Test method for hardness of monolithic
ceramics at room temperature
Céramiques techniques — Méthode d’essai de dureté des céramiques monolithiques à température ambiante
ICS: 81.060.30
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 14705:2015(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
©
PROVIDE SUPPORTING DOCUMENTATION. ISO 2015
ISO/DIS 14705:2015(E)
© 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
ISO/DIS 14705
Contents Page
Foreword . iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Vickers hardness . 2
4.1 Principle. 2
4.2 Symbols, abbreviations and designations . 2
4.3 Significance and use . 4
4.4 Apparatus . 5
4.5 Test pieces . 5
4.6 Procedure . 5
4.7 Test report . 7
5 Knoop hardness . 10
5.1 Principle. 10
5.2 Symbols and designations . 10
5.3 Significance and use . 12
5.4 Apparatus . 12
5.5 Test pieces . 13
5.6 Procedure . 13
5.7 Test report . 14
ISO/DIS 14705
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 14705 was prepared by Technical Committee ISO/TC 206, Fine ceramics.
This second/third/. edition cancels and replaces the first/second/. edition (), [clause(s) / subclause(s) /
table(s) / figure(s) / annex(es)] of which [has / have] been technically revised.
iv © ISO 2015 – All rights reserved
DRAFT INTERNATIONAL STANDARD ISO/DIS 14705
Fine ceramics (advanced ceramics, advanced technical
ceramics) — Test method for hardness of monolithic ceramics
at room temperature
1 Scope
This International Standard specifies a test method for determining the Vickers and Knoop hardness of
monolithic fine ceramics at room temperature.
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 4545-1:2005, Metallic materials — Knoop hardness test — Part 1: Test method
ISO 4545-2:2005, Metallic materials — Knoop hardness test — Part 2: Verification and calibration of testing
machines
ISO 4545-3:2005, Metallic materials — Knoop hardness test — Part 3: Calibration of reference blocks
ISO 4545-4:2005, Metallic materials — Knoop hardness test — Part 4: Table of hardness values
ISO 6507-1:2005, Metallic materials — Vickers hardness test — Part 1: Test method
ISO 6507-2:2005, Metallic materials — Vickers hardness test — Part 2: Verification and calibration of testing
machines
ISO 6507-3:2005, Metallic materials — Vickers hardness test — Part 3: Calibration of reference blocks
ISO 6507-4:2005, Metallic materials — Vickers hardness test — Part 4: Tables of hardness values
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
Vickers hardness
value obtained by dividing the applied force by the surface area of the indentation computed from the mean of
the measured diagonals of the indentations, assuming that the indentation is an imprint of the undeformed
indenter
3.2
Vickers indenter
indenter in the shape of a right-angle pyramid with a square base and an angle between opposite faces of
136°
See Table 1 and Figure 1.
ISO/DIS 14705
3.3
Knoop hardness
value obtained by dividing the applied force by the projected area of the indentation computed from the
measurement of the long diagonal of the indentation, assuming that the indentation is an imprint of the
undeformed indenter
3.4
Knoop indenter
indenter in the shape of a rhombic-based pyramid with the two angles between the opposite edges at 172,5°
and 130°
See Table 3 and Figure 6.
4 Vickers hardness
4.1 Principle
Forcing a diamond indenter in the form of a right-angle pyramid with a square base, and with a specified angle
between opposite faces at the vertex into the surface of a test piece and measuring the length of the
diagonals of the indentation left in the surface after removal of the test force, F. See Figures 1 and 2.
4.2 Symbols, abbreviations and designations
4.2.1 See Table 1 and Figures 1 and 2.
4.2.2 The Vickers hardness is denoted by the symbol HV preceded by the hardness value and followed by
a number representing the test force (see Table 2).
EXAMPLES
1 500 HV 1 represents a Vickers hardness number of 1 500, determined with a test force of 9,807 N (1 kgf).
2 © ISO 2015 – All rights reserved
ISO/DIS 14705
Table 1 — Symbols, abbreviations and designations for Vickers hardness testing
Symbol or
Designation
abbreviation
Angle between the opposite faces at the vertex of the pyramidal indenter (136° 0,5°)
F Test force, in newtons
d Arithmetic mean, in millimetres, of the two diagonals d and d
1 2
HV Vickers hardness
Test force
Constant
Surface area of indentation
136
2F sin
F
0,102 0,189 1
dd
c Arithmetic mean of the half of the two median crack lengths 2c and 2c
1 2
S.D. Standard deviation
HV HV
n
n 1
where
HV
n
HV is the arithmetic mean of the Vickers hardness
n
HV is the HV obtained from nth indentation
n
n is the number of indentations
NOTE Constant 0,102 where g is the acceleration due to gravity.
g 9,807
Table 2 — Hardness symbols and the nominal values of test forces, F, for Vickers hardness testing
Test force, F
Hardness symbol
(nominal value)
HV 0,5 4,903 N
HV 1 9,807 N
HV 2 19,61 N
HV 3 29,42 N
HV 5 49,03 N
HV 10 98,07 N
HV 20 196,1 N
ISO/DIS 14705
Figure 1 — Vickers indenter (diamond pyramid)
Figure 2 — Vickers indentation
4.3 Significance and use
Vickers indentation diagonal lengths are approximately 2,8 times shorter than the long diagonal of Knoop
indentations, and the indentation depth is approximately 1,5 times deeper than Knoop indentations made at
the same force. Vickers indentations are influenced less by the specimen surface flatness, parallelism of the
diamond axis to the test piece surface normal, and surface finish than Knoop indentations, but these
parameters should be considered nonetheless. Vickers indentations are much more likely to cause cracks in
fine ceramics than are Knoop indentations. Conversion between hardness scales shall not be made.
Vickers indentations on metallic materials are mainly formed by the plastic deformation. However, Vickers
indentations on fine ceramics are formed by micro-cracking and micro-fracture, besides plastic deformation.
This difference shall be noted for comparing the hardnesses of metals and ceramics.
4 © ISO 2015 – All rights reserved
ISO/DIS 14705
4.4 Apparatus
4.4.1 Testing machine, capable of applying a predetermined test force in the range of 4,903 N (0,5 kgf) to
98,07 N (10 kgf), preferably 9,807 N (1 kgf), in accordance with ISO 6507-2. Verification of the test force shall
be carried out in accordance with ISO 6507-2.
4.4.2 Diamond indenter, in the shape of a right-angle pyramid with a square base, as specified in
ISO 6507-1 and ISO 6507-2. Verification of the indenter shall be carried out in accordance with ISO 6507-2.
4.4.3 Measuring device, capable of measuring the indentation diagonals with a readout resolution of
0,2 µm or finer. A numerical aperture (NA) of between 0,60 and 0,95 for the objective lens for the
microscope is recommended. Verification of the measuring device shall be carried out in accordance with
ISO 6507-2.
NOTE Indirect verification can be carried out by means of standardized blocks calibrated in accordance with
ISO 6507-3, following ISO 6507-2, or other approved and traceable ceramic standard reference blocks.
4.5 Test pieces
4.5.1 The test shall be carried out on a surface which is smooth, flat and free from foreign matter. The test
piece shall be polished to permit accurate measurement of the diagonal lengths of the indentation.
Preparation shall be carried out in such a way that any alteration of the surface hardness is minimized.
4.5.2 The thickness of the test piece shall be at least 0,5 mm. It shall be at least 1,5 times the diagonal of
the indentation, d, and at least 2 times the crack length, c, whichever is greater. No indentation damage shall
be visible at the back of the test piece on completion of the test.
4.6 Procedure
4.6.1 In general, the test shall be carried out at room temperature within the limits of 10 °C to 35 °C. Tests
carried out under controlled conditions shall be made at a temperature of 23 °C 5 °C.
4.6.2 The recommended test force is 9,807 N (1 kgf). In cases where significant chipping or lateral crack-
spalling occurs or where the impression is too faint, the test forces within the range 4,903 N (0,5 kgf) to
196,1 N (20 kgf), listed in Table 2, may be used. Other instances where a heavier load may be required are
where the grain structure is very coarse and the indentation area at lower loads may contact only a few grains
of the material (e.g. a multiphase material).
4.6.3 The following items shall be confirmed before the test.
a) Check the zero of the measuring system.
b) Check the measuring system using a calibrated scale or certified indentation in a test block.
c) Check the operation of the loading system by performing a test on
...
INTERNATIONAL ISO
STANDARD 14705
Third edition
2016-12-15
Fine ceramics (advanced ceramics,
advanced technical ceramics) — Test
method for hardness of monolithic
ceramics at room temperature
Céramiques techniques — Méthode d’essai de dureté des céramiques
monolithiques à température ambiante
Reference number
©
ISO 2016
© 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
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 2016 – All rights reserved
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Vickers hardness . 2
4.1 Principle . 2
4.2 Symbols, abbreviated terms and designations . 2
4.3 Significance and use . 4
4.4 Apparatus . 5
4.5 Test pieces . 5
4.6 Procedure . 5
4.7 Accuracy and uncertainties . 7
4.8 Test report . 8
5 Knoop hardness .11
5.1 Principle .11
5.2 Symbols and designations .11
5.3 Significance and use .13
5.4 Apparatus .14
5.5 Test pieces .14
5.6 Procedure .14
5.7 Accuracy and uncertainty .15
5.8 Test report .16
Bibliography .20
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 206, Fine ceramics.
This third edition cancels and replaces the second edition (ISO 14705:2008), which has been technically
revised.
iv © ISO 2016 – All rights reserved
INTERNATIONAL STANDARD ISO 14705:2016(E)
Fine ceramics (advanced ceramics, advanced technical
ceramics) — Test method for hardness of monolithic
ceramics at room temperature
1 Scope
This document specifies a test method for determining the Vickers and Knoop hardness of monolithic
fine ceramics at room temperature.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 4545-1, Metallic materials — Knoop hardness test — Part 1: Test method
ISO 4545-2, Metallic materials — Knoop hardness test — Part 2: Verification and calibration of testing
machines
ISO 4545-4, Metallic materials — Knoop hardness test — Part 4: Table of hardness values
ISO 6507-1, Metallic materials — Vickers hardness test — Part 1: Test method
ISO 6507-2, Metallic materials — Vickers hardness test — Part 2: Verification and calibration of testing
machines
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at http://www.iso.org/obp
3.1
Vickers hardness
value obtained by dividing the applied force by the surface area of the indentation computed from the
mean of the measured diagonals of the indentations, assuming that the indentation is an imprint of the
undeformed indenter
Note 1 to entry: Vickers hardness may be expressed in two different units:
a) with unit GPa, obtained by dividing the applied force in N by the surface area of the indentation in mm ;
b) Vickers hardness number, obtained by dividing the applied force in kgf by the surface area of the
indentation in mm .
3.2
Vickers indenter
indenter in the shape of a right-angle pyramid with a square base and an angle between opposite
faces of 136°
Note 1 to entry: See Table 1 and Figure 1.
3.3
Knoop hardness
value obtained by dividing the applied force by the projected area of the indentation computed from the
measurement of the long diagonal of the indentation, assuming that the indentation is an imprint of the
undeformed indenter
Note 1 to entry: The Knoop hardness may be expressed in two different units:
a) with units of GPa, obtained by dividing the applied force in N by the projected area of the indentation in mm ;
b) Knoop hardness number, obtained by dividing the applied force in kgf by the projected area of the indentation
in mm , without units specified.
3.4
Knoop indenter
indenter in the shape of a rhombic-based pyramid with the two angles between the opposite edges at
172,5° and 130°
Note 1 to entry: See Table 3 and Figure 6.
4 Vickers hardness
4.1 Principle
Forcing a diamond indenter in the form of a right-angle pyramid with a square base, and with a specified
angle between opposite faces at the vertex into the surface of a test piece and measuring the length of
the diagonals of the indentation left in the surface after removal of the test force, F. See Figure 1 and
Figure 2.
4.2 Symbols, abbreviated terms and designations
4.2.1 See Table 1, Figure 1 and Figure 2.
4.2.2 The Vickers hardness is denoted by the symbol HV, preceded by the hardness value and followed
by a number representing the test force (see Table 2).
Examples:
a) Use of SI unit (GPa):
15,0 GPa HV 9,807 N represents a Vickers hardness of 15,0 GPa, determined with a test force of
9,807 N (1 kgf)
b) Use of the Vickers hardness number (no units specified):
1 500 HV 1 represents a Vickers hardness number of 1 500, determined with a test force of 9,807 N
(1 kgf).
2 © ISO 2016 – All rights reserved
Table 1 — Symbols, abbreviated terms and designations for Vickers hardness testing
Symbol or
abbreviated Designation
term
α Angle between the opposite faces at the vertex of the pyramidal indenter (136° ± 0,5°)
F Test force, in newtons
d Arithmetic mean, in millimetres, of the two diagonals, d and d
1 2
HV Vickers hardness
Test force
=×Constant
Surfaceareaofindentation
a) Units of GPa
136°
2Fsin
F
=0,001 =0,001 854
d d
b) Hardness number (no units specified)
136°
2Fsin
F
=0,102 =0,1891
d d
c Arithmetic mean of the half of the two median crack lengths, 2c and 2c
1 2
SD Standard deviation
HV −HV
()
∑ n
=
n−1
where
HV
∑ n
HV is the arithmetic mean of the Vickers hardness = ;
n
HV is the HV obtained from nth indentation;
n
n is the number of indentations.
NOTE Constant =0,102 , where g is the acceleration due to gravity.
g 9,807
Table 2 — Hardness symbols and the nominal values of test forces, F, for Vickers hardness testing
Test force, F
Hardness symbol
(nominal value)
HV 0,5 4,903 N
HV 1 9,807 N
HV 2 19,61 N
HV 3 29,42 N
HV 5 49,03 N
HV 10 98,07 N
HV 20 196,1 N
==
Figure 1 — Vickers indenter (diamond pyramid)
Figure 2 — Vickers indentation
4.3 Significance and use
Vickers indentation diagonal lengths are approximately 2,8 times shorter than the long diagonal
of Knoop indentations, and the indentation depth is approximately 1,5 times deeper than Knoop
indentations made at the same force. Vickers indentations are influenced less by the specimen surface
flatness, parallelism of the diamond axis to the test piece surface normal, and surface finish than Knoop
indentations, but these parameters should be considered nonetheless. Vickers indentations are much
more likely to cause cracks in fine ceramics than Knoop indentations. Conversion between hardness
scales shall not be made.
Vickers indentations on metallic materials are mainly formed by the plastic deformation. However,
Vickers indentations on fine ceramics are formed by micro-cracking and micro-fracture, besides plastic
deformation. This difference shall be noted for comparing the hardness of metals and ceramics.
4 © ISO 2016 – All rights reserved
4.4 Apparatus
4.4.1 Testing machine, capable of applying a predetermined test force in the range of 4,903 N (0,5 kgf)
to 98,07 N (10 kgf), preferably 9,807 N (1 kgf), in accordance with ISO 6507-2. Verification of the test
force shal
...
NORME ISO
INTERNATIONALE 14705
Troisième édition
2016-12-15
Céramiques techniques — Méthode
d'essai de dureté des céramiques
monolithiques à température
ambiante
Fine ceramics (advanced ceramics, advanced technical ceramics) —
Test method for hardness of monolithic ceramics at room temperature
Numéro de référence
©
ISO 2016
DOCUMENT PROTÉGÉ PAR COPYRIGHT
© ISO 2016
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publication ne peut être reproduite ni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique,
y compris la photocopie, ou la diffusion sur l’internet ou sur un intranet, sans autorisation écrite préalable. Une autorisation peut
être demandée à l’ISO à l’adresse ci-après ou au comité membre de l’ISO dans le pays du demandeur.
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Publié en Suisse
ii © ISO 2016 – Tous droits réservés
Sommaire Page
Avant-propos .iv
1 Domaine d’application . 1
2 Références normatives . 1
3 Termes et définitions . 1
4 Dureté Vickers . 2
4.1 Principe . 2
4.2 Symboles, abréviations et désignations . 2
4.3 Portée et utilisation . 4
4.4 Appareillage. 5
4.5 Éprouvettes . 5
4.6 Mode opératoire . 5
4.7 Exactitude et incertitudes . 8
4.8 Rapport d’essai . 9
5 Dureté Knoop .12
5.1 Principe .12
5.2 Symboles et désignations .12
5.3 Portée et utilisation .14
5.4 Appareillage.14
5.5 Éprouvettes .15
5.6 Mode opératoire .15
5.7 Exactitude et incertitudes .16
5.8 Rapport d’essai .17
Bibliographie .21
Avant-propos
L’ISO (Organisation internationale de normalisation) est une fédération mondiale d’organismes
nationaux de normalisation (comités membres de l’ISO). L’élaboration des Normes internationales est
en général confiée aux comités techniques de l’ISO. Chaque comité membre intéressé par une étude
a le droit de faire partie du comité technique créé à cet effet. Les organisations internationales,
gouvernementales et non gouvernementales, en liaison avec l’ISO participent également aux travaux.
L’ISO collabore étroitement avec la Commission électrotechnique internationale (IEC) en ce qui
concerne la normalisation électrotechnique.
Les procédures utilisées pour élaborer le présent document et celles destinées à sa mise à jour sont
décrites dans les Directives ISO/IEC, Partie 1. Il convient, en particulier de prendre note des différents
critères d’approbation requis pour les différents types de documents ISO. Le présent document a été
rédigé conformément aux règles de rédaction données dans les Directives ISO/IEC, Partie 2 (voir www
.iso .org/ directives).
L’attention est attirée sur le fait que certains des éléments du présent document peuvent faire l’objet de
droits de propriété intellectuelle ou de droits analogues. L’ISO ne saurait être tenue pour responsable
de ne pas avoir identifié de tels droits de propriété et averti de leur existence. Les détails concernant
les références aux droits de propriété intellectuelle ou autres droits analogues identifiés lors de
l’élaboration du document sont indiqués dans l’Introduction et/ou dans la liste des déclarations de
brevets reçues par l’ISO (voir www .iso .org/ brevets).
Les appellations commerciales éventuellement mentionnées dans le présent document sont données
pour information, par souci de commodité, à l’intention des utilisateurs et ne sauraient constituer un
engagement.
Pour une explication de la signification des termes et expressions spécifiques de l'ISO liés à l'évaluation
de la conformité, ou pour toute information au sujet de l'adhésion de l'ISO aux principes de l'OMC
concernant les obstacles techniques au commerce (OTC), voir le lien suivant: www .iso .org/ iso/ fr/
avant-propos.
Le présent document a été élaboré par le comité technique ISO/TC 206, Céramiques techniques.
Cette troisième édition annule et remplace la deuxième édition (ISO 14705:2008) qui a fait l’objet d’une
révision technique.
iv © ISO 2016 – Tous droits réservés
NORME INTERNATIONALE ISO 14705:2016(F)
Céramiques techniques — Méthode d'essai de dureté des
céramiques monolithiques à température ambiante
1 Domaine d’application
Le présent document spécifie une méthode d’essai pour déterminer la dureté Vickers et Knoop des
céramiques techniques monolithiques à température ambiante.
2 Références normatives
Les documents suivants sont cités dans le texte de sorte qu’ils constituent, pour tout ou partie de leur
contenu, des exigences du présent document. Pour les références datées, seule l’édition citée s’applique.
Pour les références non datées, la dernière édition du document de référence s’applique (y compris les
éventuels amendements).
ISO 4545-1, Matériaux métalliques — Essai de dureté Knoop — Partie 1: Méthode d'essai
ISO 4545-2, Matériaux métalliques — Essai de dureté Knoop — Partie 2: Vérification et étalonnage des
machines d'essai
ISO 4545-4, Matériaux métalliques — Essai de dureté Knoop — Partie 4: Tableau des valeurs de dureté
ISO 6507-1, Matériaux métalliques — Essai de dureté Vickers — Partie 1: Méthode d'essai
ISO 6507-2, Matériaux métalliques — Essai de dureté Vickers — Partie 2: Vérification et étalonnage des
machines d'essai
3 Termes et définitions
Pour les besoins du présent document, les termes et définitions suivants s’appliquent.
L’ISO et l’IEC tiennent à jour des bases de données terminologiques destinées à être utilisées en
normalisation, consultables aux adresses suivantes:
— IEC Electropedia: disponible à l’adresse http:// www .electropedia .org/
— ISO Online browsing platform: disponible à l’adresse https:// www .iso .org/ obp
3.1
dureté Vickers
valeur obtenue en divisant la force appliquée par l’aire de l’empreinte calculée à partir de la moyenne des
diagonales mesurées des empreintes, en supposant que l’empreinte est celle du pénétrateur non déformé
Note 1 à l'article: La dureté Vickers peut être exprimée en deux unités différentes:
a) avec l’unité GPa, obtenue en divisant la force appliquée en N par l’aire de l’empreinte en mm ;
b) avec l’indice de dureté Vickers, obtenu en divisant la force appliquée en kgf par l’aire de l’empreinte en mm .
3.2
pénétrateur Vickers
pénétrateur en forme de pyramide à angle droit et base carrée, avec un angle de 136° entre les faces
opposées
Note 1 à l'article: Voir le Tableau 1 et la Figure 1.
3.3
dureté Knoop
valeur obtenue en divisant la force appliquée par l’aire projetée de l’empreinte calculée à partir de la
mesure de la grande diagonale de l’empreinte, en supposant que l’empreinte est celle du pénétrateur
non déformé
Note 1 à l'article: La dureté Knoop peut être exprimée en deux unités différentes:
a) avec des unités de GPa, obtenues en divisant la force appliquée en N par l’aire projetée de l’empreinte en mm ;
b) avec l’indice de dureté Knoop, obtenu en divisant la force appliquée en kgf par l’aire projetée de l’empreinte
en mm , sans unités spécifiées.
3.4
pénétrateur Knoop
pénétrateur en forme de pyramide à base rhombique, dont les deux angles entre les bords opposés sont
égaux à 172,5° et 130°
Note 1 à l'article: Voir le Tableau 3 et la Figure 6.
4 Dureté Vickers
4.1 Principe
Imprimer à la surface d’une éprouvette un pénétrateur en diamant en forme de pyramide à angle droit
et base carrée, avec un angle spécifié entre les faces opposées au sommet et mesurer la longueur des
diagonales de l’empreinte laissée sur la surface après suppression de la force d’essai, F. Voir la Figure 1
et la Figure 2.
4.2 Symboles, abréviations et désignations
4.2.1 Voir le Tableau 1, la Figure 1 et la Figure 2.
4.2.2 La dureté Vickers est désignée par le symbole HV, précédé de la valeur de dureté et suivi d’un
nombre représentant la force d’essai (voir le Tableau 2).
Exemples
a) utilisation de l’unité SI (GPa):
15,0 GPa HV 9,807 N représente une dureté Vickers de 15,0 GPa, déterminée avec une force d’essai
de 9,807 N (1 kgf);
b) utilisation de l’indice de dureté Vickers (aucune unité spécifiée):
1 500 HV 1 représente un indice de dureté Vickers de 1 500, déterminé avec une force d’essai de
9,807 N (1 kgf).
2 © ISO 2016 – Tous droits réservés
Tableau 1 — Symboles, abréviations et désignations pour les essais de dureté Vickers
Symbole ou
Désignation
abréviation
α Angle entre les faces opposées au sommet du pénétrateur pyramidal (136° ± 0,5°)
F Force d’essai, en newtons
d Moyenne arithmétique, en millimètres, des deux diagonales d et d
1 2
HV Dureté Vickers
Force d'essai
=×Constante
Aire de l'empreinte
a) Unités de GPa
136°
2Fsin
F
=0,001 =0,001 854
d d
b) Indice de dureté (aucune unité spécifiée)
136°
2Fsin
F
=0,102 =0,1891
d d
c Moyenne arithmétique de la moitié des deux longueurs médianes de fissures, 2c et 2c
1 2
SD Écart-type
HV −HV
()
∑ n
=
n−1
où
HV
∑ n
HV est la moyenne arithmétique de la dureté Vickers = ;
n
HV est la HV obtenue à partir de la nème empreinte;
n
n est le nombre d’empreintes.
NOTE Constante== =0,102 , où g est l’accélération due à la gravité.
g 9,807
Tableau 2 — Symboles de dureté et valeurs nominales des forces d’essai, F, pour les essais de
dureté Vickers
Force d’essai, F
Symbole de la dureté
(valeur nominale)
HV 0,5 4,903 N
HV 1 9,807 N
HV 2 19,61 N
HV 3 29,42 N
HV 5 49,03 N
HV 10 98,07 N
HV 20 196,1 N
Figure 1 — Pénétrateur Vickers (pyramide en diamant)
Figure 2 — Empreinte Vickers
4.3 Portée et utilisation
Les longueurs diagonales des empreintes Vickers sont environ 2,8 fois plus courtes que la grande
diagonale des empreintes Knoop, et la profondeur d’empreinte est environ 1,5 fois plus profonde que les
empreintes Knoop faites à la même force. Les empreintes Vickers sont moins influencées par la planéité
de la surface de l’échantillon, le parallélisme de l’axe du diamant par rapport à la normale de la surface
de l’éprouvette et le fini de surface que les empreintes Knoop, mais il convient toutefois de prendre
ces paramètres en compte. Les empreintes Vickers sont beaucoup plus susceptibles de provoquer des
fiss
...
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