1、BS ISO 14705:2016Fine ceramics (advancedceramics, advanced technicalceramics) Test methodfor hardness of monolithicceramics at room temperatureBSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06BS ISO 14705:2016 BRITISH STANDARDNational forewordThis British Standard is
2、the UK implementation of ISO 14705:2016. The UK participation in its preparation was entrusted to TechnicalCommittee RPI/13, Advanced technical ceramics.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all t
3、he necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2016. Published by BSI Standards Limited 2016ISBN 978 0 580 91302 0ICS 81.060.30Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Stand
4、ard was published under the authority of theStandards Policy and Strategy Committee on 31 December 2016.Amendments/Corrigenda issued since publicationDate Text affectedBS ISO 14705:2016 ISO 2016Fine ceramics (advanced ceramics, advanced technical ceramics) Test method for hardness of monolithic cera
5、mics at room temperatureCramiques techniques Mthode dessai de duret des cramiques monolithiques temprature ambianteINTERNATIONAL STANDARDISO14705Third edition2016-12-15Reference numberISO 14705:2016(E)BS ISO 14705:2016ISO 14705:2016(E)ii ISO 2016 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2
6、016, Published in SwitzerlandAll 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
7、. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester.ISO copyright officeCh. de Blandonnet 8 CP 401CH-1214 Vernier, Geneva, SwitzerlandTel. +41 22 749 01 11Fax +41 22 749 09 47copyrightiso.orgwww.iso.orgBS ISO 14705:2016ISO 14705:2016
8、(E)Foreword iv1 Scope . 12 Normative references 13 Terms and definitions . 14 Vickers hardness 24.1 Principle 24.2 Symbols, abbreviated terms and designations 24.3 Significance and use . 44.4 Apparatus 54.5 Test pieces . 54.6 Procedure 54.7 Accuracy and uncertainties 74.8 Test report . 85 Knoop hard
9、ness 115.1 Principle . 115.2 Symbols and designations 115.3 Significance and use 135.4 Apparatus . 145.5 Test pieces 145.6 Procedure . 145.7 Accuracy and uncertainty . 155.8 Test report 16Bibliography .20 ISO 2016 All rights reserved iiiContents PageBS ISO 14705:2016ISO 14705:2016(E)ForewordISO (the
10、 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 committe
11、e 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 electrotechni
12、cal 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
13、 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. D
14、etails 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
15、 endorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL: www.iso.org/iso/foreword
16、.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 reservedBS ISO 14705:2016INTERNATIONAL STANDARD ISO 14705:2016(E)Fine ceramics (advanc
17、ed ceramics, advanced technical ceramics) Test method for hardness of monolithic ceramics at room temperature1 ScopeThis document specifies a test method for determining the Vickers and Knoop hardness of monolithic fine ceramics at room temperature.2 Normative referencesThe following documents are r
18、eferred 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 materi
19、als Knoop hardness test Part 1: Test methodISO 4545-2, Metallic materials Knoop hardness test Part 2: Verification and calibration of testing machinesISO 4545-4, Metallic materials Knoop hardness test Part 4: Table of hardness valuesISO 6507-1, Metallic materials Vickers hardness test Part 1: Test m
20、ethodISO 6507-2, Metallic materials Vickers hardness test Part 2: Verification and calibration of testing machines3 Terms and definitionsFor the purposes of this document, the following terms and definitions apply.ISO and IEC maintain terminological databases for use in standardization at the follow
21、ing addresses: IEC Electropedia: available at http:/www.electropedia.org/ ISO Online browsing platform: available at http:/www.iso.org/obp3.1Vickers hardnessvalue obtained by dividing the applied force by the surface area of the indentation computed from the mean of the measured diagonals of the ind
22、entations, assuming that the indentation is an imprint of the undeformed indenterNote 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 mm2;b) Vickers hardness number, obtained
23、by dividing the applied force in kgf by the surface area of the indentation in mm2. ISO 2016 All rights reserved 1BS ISO 14705:2016ISO 14705:2016(E)3.2Vickers indenterindenter in the shape of a right-angle pyramid with a square base and an angle between opposite faces of 136Note 1 to entry: See Tabl
24、e 1 and Figure 1.3.3Knoop hardnessvalue 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 indenterNote 1 to entry: The Knoop hardness may
25、 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 mm2;b) Knoop hardness number, obtained by dividing the applied force in kgf by the projected area of the indentation in mm2, without units specified.3.4K
26、noop indenterindenter in the shape of a rhombic-based pyramid with the two angles between the opposite edges at 172,5 and 130Note 1 to entry: See Table 3 and Figure 6.4 Vickers hardness4.1 PrincipleForcing a diamond indenter in the form of a right-angle pyramid with a square base, and with a specifi
27、ed 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 designations4.2.1 See Table 1, Figure 1 and
28、 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
29、(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 reservedBS ISO 14705:2016ISO 14705:2016(E)Table 1 Symbols, abbreviated terms and designations for Vickers
30、 hardness testingSymbol or abbreviated termDesignation Angle between the opposite faces at the vertex of the pyramidal indenter (136 0,5)F Test force, in newtonsd Arithmetic mean, in millimetres, of the two diagonals, d1and d2HV Vickers hardness=ConstantTest forceSurfaceareaofindentationa) Units of
31、GPa=0 001213620 001 85422,sin,FdFdb) Hardness number (no units specified)=0 102213620 189122,sin,FdFdc Arithmetic mean of the half of the two median crack lengths, 2c1and 2c2SD Standard deviation=()HV HVnn21whereHV is the arithmetic mean of the Vickers hardness =HVnn;HVnis the HV obtained from nth i
32、ndentation;n is the number of indentations.NOTE Constant = = =119 8070 102g , , where g is the acceleration due to gravity.Table 2 Hardness symbols and the nominal values of test forces, F, for Vickers hardness testingHardness symbolTest force, F (nominal value)HV 0,5 4,903 NHV 1 9,807 NHV 2 19,61 N
33、HV 3 29,42 NHV 5 49,03 NHV 10 98,07 NHV 20 196,1 N ISO 2016 All rights reserved 3BS ISO 14705:2016ISO 14705:2016(E)Figure 1 Vickers indenter (diamond pyramid)Figure 2 Vickers indentation4.3 Significance and useVickers indentation diagonal lengths are approximately 2,8 times shorter than the long dia
34、gonal 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 tha
35、n 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 pl
36、astic 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 reservedBS ISO 14705:2016ISO 14705:2016(E)4.4 Apparat
37、us4.4.1 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 s
38、hape 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 m or finer. A numerical
39、 aperture (NA) 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-
40、3, following ISO 6507-2, or other approved and traceable ceramic standard reference blocks.4.5 Test pieces4.5.1 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 th
41、e indentation. Preparation shall be carried out in such a way that any alteration of the surface hardness is minimized. Surfaces shall not be thermally or chemically etched. If applicable, residual surface stresses shall be removed by suitable polishing or annealing procedures.4.5.2 The thickness of
42、 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 upon completion of the test.4.6 Procedure4.6.1 In general,
43、 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 test force shall be 9,807 N (1 kgf). In cases where significant chipping or lateral crack-spalling occurs or where
44、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
45、 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 perform
46、ing a test on a certified test block.d) Check the condition of the indenter by examining the indentation made in the test block. Replace the indenter, if necessary, by taking into account the conditions given in 4.6.10.e) A test block with high hardness has to be used in order to obtain impressions
47、in the same size range as expected during tests on ceramics.4.6.4 The indenter shall be cleaned prior to and during the test series, as ceramic powders or fragments from the ceramic test piece can adhere to the diamond indenter. ISO 2016 All rights reserved 5BS ISO 14705:2016ISO 14705:2016(E)4.6.5 T
48、he test piece shall be placed on a rigid support. The support surface shall be clean and free from foreign matter. It is important that the test piece lies firmly on the support, so that displacement cannot occur during the test.4.6.6 Carefully adjust the illumination and focusing conditions, in ord
49、er to obtain the optimum view and clarity of the indentation. Both indentation tips shall be in focus at the same time. Do not change the focus when measuring the distance from tip to tip.4.6.7 Bring the indenter into contact with the test surface and apply the test force in a direction perpendicular to the surface, without shock or vibration, until the applied force attains the specified value. The time from the initial application of the force until the full test forc
