BS ISO 19207-2016 Thermal spraying Classification method of adhesive strength by indentation《热喷涂 压痕法测定粘结强度的分类方法》.pdf

1、BS ISO 19207:2016Thermal spraying Classification methodof adhesive strength byindentationBSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06BS ISO 19207:2016 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 19207:2016.The UK partici

2、pation in its preparation was entrusted to TechnicalCommittee STI/40, Thermal spraying and thermally sprayed coatings.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contrac

3、t. Users are responsible for its correctapplication. The British Standards Institution 2016.Published by BSI Standards Limited 2016ISBN 978 0 580 85102 5ICS 25.220.01Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authorit

4、y of theStandards Policy and Strategy Committee on 30 September 2016.Amendments/corrigenda issued since publicationDate T e x t a f f e c t e dBS ISO 19207:2016 ISO 2016Thermal spraying Classification method of adhesive strength by indentationProjection thermique Mthode de classification de la rsist

5、ance adhsive par indentationINTERNATIONAL STANDARDISO19207First edition2016-09-15Reference numberISO 19207:2016(E)BS ISO 19207:2016ISO 19207:2016(E)ii ISO 2016 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2016, Published in SwitzerlandAll rights reserved. Unless otherwise specified, no part o

6、f 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 ISOs member body

7、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 19207:2016ISO 19207:2016(E)Foreword ivIntroduction v1 Scope . 12 Normative references 13 Terms and definitions

8、. 14 Symbols and units . 15 Principle 36 Test pieces and sample preparation 36.1 Thicknesses of coating and substrate . 46.2 Sample size . 46.3 Sample cutting . 46.4 Mounting 46.5 Surface preparation 47 Apparatus . 57.1 Indentation testing machines . 57.2 Indenter . 57.3 Impression and crack measure

9、ments . 68 Procedure and conditions of testing 68.1 Indentation . 68.2 Impression and crack length measurement 78.2.1 General 78.2.2 Method A . 78.2.3 Method B . 79 Evaluation of adhesion index 99.1 Criterions of interfacial crack initiation and critical indentation force . 99.2 Classification of ad

10、hesive strength and notation of adhesion index 99.3 Test validity . 1110 Test report 1210.1 Items to be reported 1210.2 Items to be selected to report . 12Bibliography .13 ISO 2016 All rights reserved iiiContents PageBS ISO 19207:2016ISO 19207:2016(E)ForewordISO (the International Organization for S

11、tandardization) 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 ri

12、ght 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 procedure

13、s 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 ru

14、les 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 ident

15、ified 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 o

16、n 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.html.The committee responsible f

17、or this document is ISO/TC 107, Metallic and other inorganic coatings.iv ISO 2016 All rights reservedBS ISO 19207:2016ISO 19207:2016(E)IntroductionAdhesion of coatings specified here is required for three reasons: for selection of coating material and spray method; for quality assurance of thermal s

18、praying; for product design and performance assessment of coatings.This International Standard provides the classification method of adhesive strength for thermal spray coatings by using Vickers hardness testing machine generally and widely used. In the present test method, a pyramidal Vickers diamo

19、nd indenter is indented with test force at the interface of coatings. When the test force exceeds the threshold value corresponding to the adhesive strength, an interfacial crack is generated. Accordingly, it is possible to evaluate the adhesive strength of coatings by the test force applied as disc

20、rete values when using conventional Vickers testing machine. This International Standard classifies the adhesive strength, called adhesion index, evaluated from the maximum indentation force without visible cracking and can be also applied to evaluate coatings with a high adhesive, such as cermet co

21、atings. The present test method can be applied to sprayed coatings if the crack initiated by the indentation can be observed by using optical microscope.The maximum indentation force does not therefore require much more effort in the experimental procedure and can describe the property of system com

22、bination (substrate chemistry, pre-preparation/roughness of substrate surface, coating chemistry and spraying related coating properties), provided the measurements are obtained carefully in line with the methods proposed in this International Standard. This International Standard recommends good pr

23、actice to minimize levels of uncertainty in the measurement process. The procedure has been validated through underpinning technical work within the round robin test programme conducted by the Subcommittee on Standard Development, Japan Thermal Spray Society. ISO 2016 All rights reserved vBS ISO 192

24、07:2016BS ISO 19207:2016Thermal spraying Classification method of adhesive strength by indentation1 ScopeThis International Standard specifies the classification method of adhesive strength for thermal spray coatings at room temperature by using Vickers hardness testing machine. This International S

25、tandard classifies the adhesive strength, called adhesion index, evaluated from the maximum indentation force without visible cracking, and it is applicable for relative dense metal coatings, ceramic coatings and cermet coatings. This International Standard can be used within comparison within each

26、coating system.The indentation method is not recommended for very thin and very porous coatings and also for the coating system with lower cohesion strength than adhesion strength. It is recommended that this test method can be applied for a coating of which porosity is less than approximately 15 %.

27、2 Normative referencesThe 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 amendm

28、ents) applies.ISO 6507-1, Metallic materials Vickers hardness test Part 1: Test methodISO 6507-2, Metallic materials Vickers hardness test Part 2: Verification and calibration of testing machinesISO 14917, Thermal spraying Terminology, classificationISO 14923, Thermal spraying Characterization and t

29、esting of thermally sprayed coatings3 Terms and definitionsFor the purposes of this document, the terms and definitions given in ISO 14917, ISO 14923 and the following apply.3.1critical indentation forcemaximum indentation force without visible cracking between substrate and coating3.2adhesion index

30、AIindex of adhesive strength of coatings defined by the critical indentation force4 Symbols and unitsFor the purposes of this document, the following symbols and units apply (see Figures 1 and 2).INTERNATIONAL STANDARD ISO 19207:2016(E) ISO 2016 All rights reserved 1BS ISO 19207:2016ISO 19207:2016(E

31、)Table 1 Symbols and designationsSymbol Designation Unita Impression-diagonal half-length parallel to interface mme Visible crack length mean value mme1, e2Individual crack lengths at corner of an impression (lengths from crack tip to edge of impression diagonal, parallel with the macroscopic interf

32、ace)mmF Test force (indentation force) NFeqEquivalent indentation force when using the special conical indenter NH Mean value in impression position mmH1, H2Individual impression position mml Sample length mmT Mean value in crack tip position mmT1, T2Individual crack tip position mmt Coating thickne

33、ss mmtsSubstrate thickness mmw Sample width mmCF Visible cracking frequency %NcNumber of indentations with visible cracking NtTotal number of indentations Key1 coating2 substrate (or bond coat)3 interface4 impression5 visible crackFigure 1 Schematic diagram of indentation characteristics2 ISO 2016 A

34、ll rights reservedBS ISO 19207:2016ISO 19207:2016(E)Key1 coating2 substrate (with bond coat)Figure 2 Sample geometry5 PrincipleWhen a pyramidal Vickers diamond indenter is indented with the indentation force at the interface (see Figure 3), an interfacial crack opening force that acts perpendicularl

35、y to the interface is generated. This crack opening force is proportional to the test force. When the crack opening force exceeds, the adhesive strength of the test piece, an interfacial crack is generated. Accordingly, it is possible to classify the adhesive strength of the test piece by the indent

36、ation force applied using the Vickers indenter.Key1 coating2 substrate (with bond coat)3 visible crack4 Vickers diamond indenterFigure 3 Interfacial indentation test6 Test pieces and sample preparationThe surface of the substrate to be coated by spraying shall be flat. After thermal spraying, sample

37、s are cut from the coated plate. Samples shall be coated of resin so as to obtain the specimen to be polished before proceeding to the test (see Figure 4).In the samples, the thermal spray coating shall be adhered to the base material (or bond coating) and any cracking is not acceptable in the evalu

38、ation section before the test. ISO 2016 All rights reserved 3BS ISO 19207:2016ISO 19207:2016(E)Key1 coating samples2 resinFigure 4 Test piece for indentation test6.1 Thicknesses of coating and substrateThe substrate shall have sufficient thickness in order to eliminate the effect of that in the expe

39、rimental results. It is recommended that the thickness of substrate, ts, (see Figure 2) is at least 5 mm.The minimum thickness of the thermal spray coating, t, (see Figure 2) shall be at least twice the half-length of the impression in the case of high stiffness coatings, such as WC-12Co cermet coat

40、ing. It is recommended that the thickness of coating is at least five times the half-length of the impression in the case of low stiffness coatings, such as thermal barrier coating which has very low elastic modulus.6.2 Sample sizeThe width of the cut samples, w, (see Figure 2) shall be sufficiently

41、 greater than the depth of the indentation. It is recommended that the width of the cut sample is at least 5 mm.The length of the cut samples, l, (see Figure 2) shall be of a sufficient length to enable the indenter to be applied at adequate intervals. It is recommended that the length of the cut sa

42、mples, l, is longer than 20 mm.6.3 Sample cuttingThe appropriate cutting method and condition shall be selected in order to prevent the cutting to damage the sample. Wheel cutting or electro spark discharge machines are convenient to use for the cutting.6.4 MountingThe samples shall be embedded in r

43、esin without the gap between the resin and the samples. It is recommended that the sample is embedded in resin after it has been bonded to a rigid supporting jig when higher testing force is applied.6.5 Surface preparationThe test surfaces shall be polished. The polished sample surface finish should

44、 be adequate enough to enable determination of the lengths of the impression diagonal and the crack. It is recommended that the test surface is buffed with the alumina or diamond powder to mirror surface as the final polishing.The test shall be carried out on a surface which is free from the damaged

45、 layer induced by cutting and other specimen preparations.4 ISO 2016 All rights reservedBS ISO 19207:2016ISO 19207:2016(E)7 Apparatus7.1 Indentation testing machinesThe indentation testing machine shall have the capability of applying predetermined indentation forces within the required scope and sh

46、all fulfil the requirements of ISO 6507-2.7.2 IndenterThe indenter for use with testing machines shall be a standard Vickers indenter in the shape of a right pyramid with a square base specified in ISO 6507-2.When no interfacial visible crack is generated using a standard Vickers indenter due to the

47、 high adhesive strength of coatings, a special conical diamond indenter with a point angle of 70 and a point radius of 0,05 mm can be used (see Figure 5).When the special conical indenter is used, the dimensions are defined as shown in Figure 6.Figure 5 Shape of special conical indenter ISO 2016 All

48、 rights reserved 5BS ISO 19207:2016ISO 19207:2016(E)Key1 coating2 substrate3 interface4 impression5 visible crackFigure 6 Schematic diagram of indentation characteristics for special conical indenter7.3 Impression and crack measurementsThe diagonal and crack dimensions can be measured using an optic

49、al microscope attached or separated with the indentation testing machine, but it shall have been calibrated against a standard.It is recommended that the lengths of impression diagonal and crack can be measured at a magnification satisfying the resolution of at least 10 m. (The recommended magnification is 200.)8 Procedure and conditions of testing8.1 IndentationIndentation shall be carried out on a Vickers hardness testing machine in accordance with the method in ISO 6507-1 for the Vickers hardness test.The te