BS ISO 19674-2017 Fine ceramics (advanced ceramics advanced technical ceramics) Methods of test for ceramic coatings Determination of internal stress in ceramic coatings by applica.pdf

1、Fine ceramics (advanced ceramics, advanced technical ceramics) Methods of test for ceramic coatings Determination of internal stress in ceramic coatings by application of the Stoney formulaBS ISO 19674:2017BSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06 ISO 2017Fine

2、 ceramics (advanced ceramics, advanced technical ceramics) Methods of test for ceramic coatings Determination of internal stress in ceramic coatings by application of the Stoney formulaCramiques fines (cramiques avances, cramiques techniques avances) Mthodes dessai des revtements cramiques Dterminat

3、ion de la contrainte interne des revtements cramiques par application de la formule de StoneyINTERNATIONAL STANDARDISO19674First edition2017-09Reference numberISO 19674:2017(E)National forewordThis British Standard is the UK implementation of ISO 19674:2017.The UK participation in its preparation wa

4、s entrusted to Technical Committee RPI/13, Advanced technical ceramics.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct appl

5、ication. The British Standards Institution 2017 Published by BSI Standards Limited 2017ISBN 978 0 580 88670 6ICS 81.060.30Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Comm

6、ittee on 30 September 2017.Amendments/corrigenda issued since publicationDate Text affectedBRITISH STANDARDBS ISO 19674:2017 ISO 2017Fine ceramics (advanced ceramics, advanced technical ceramics) Methods of test for ceramic coatings Determination of internal stress in ceramic coatings by application

7、 of the Stoney formulaCramiques fines (cramiques avances, cramiques techniques avances) Mthodes dessai des revtements cramiques Dtermination de la contrainte interne des revtements cramiques par application de la formule de StoneyINTERNATIONAL STANDARDISO19674First edition2017-09Reference numberISO

8、19674:2017(E)BS ISO 19674:2017ISO 19674:2017(E)ii ISO 2017 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2017, 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

9、 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 in the country of the requester.ISO copyright officeCh. de Blandonnet 8 CP 401CH-1214 Vernier, Geneva

10、, SwitzerlandTel. +41 22 749 01 11Fax +41 22 749 09 47copyrightiso.orgwww.iso.orgBS ISO 19674:2017ISO 19674:2017(E)ii ISO 2017 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2017, Published in SwitzerlandAll rights reserved. Unless otherwise specified, no part of this publication may be reprodu

11、ced 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 in the country of the requester.I

12、SO copyright officeCh. de Blandonnet 8 CP 401CH-1214 Vernier, Geneva, SwitzerlandTel. +41 22 749 01 11Fax +41 22 749 09 47copyrightiso.orgwww.iso.orgISO 19674:2017(E)Foreword ivIntroduction v1 Scope . 12 Normative references 13 Terms and definitions . 14 Principle 15 Apparatus . 26 Preparation of te

13、st specimens 36.1 Material . 36.2 Sample geometry 36.3 Sample surface finish . 46.4 Sample dimensions . 47 Procedure. 47.1 Measuring range and initial profile . 47.2 Deposition of the coating . 57.3 Coating thickness 57.4 Adjusting the sample geometry after deposition of the coating 57.5 Measuring t

14、he final profile . 67.6 Calculation of stress 67.7 Number of repeat measurements . 78 Limits to method . 79 Test report . 7Annex A (informative) Determination of suitable dimensions for the test sample . 8Bibliography .10 ISO 2017 All rights reserved iiiContents PageBS ISO 19674:2017ISO 19674:2017(E

15、)ForewordISO (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 t

16、echnical 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

17、 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 docume

18、nt 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 s

19、uch 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

20、 does not constitute an endorsement.For an explanation on the voluntary nature of standards, 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 T

21、rade (TBT) see the following URL: www .iso .org/ iso/ foreword .html.This document was prepared by Technical Committee ISO/TC 206, Fine ceramics.iv ISO 2017 All rights reservedBS ISO 19674:2017ISO 19674:2017(E)ForewordISO (the International Organization for Standardization) is a worldwide federation

22、 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.

23、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

24、 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 (se

25、e 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 do

26、cument 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 voluntary nature of standards

27、, 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.This document was prep

28、ared by Technical Committee ISO/TC 206, Fine ceramics.iv ISO 2017 All rights reserved ISO 19674:2017(E)IntroductionThere is an increasing use of coatings to improve the functional performance of materials and components. This can be to protect against damage due to exposure to demanding environments

29、 including high stresses and aggressive chemical environments, but can also be to modify many other properties, e.g. thermal conductivity through thermal barrier coatings, friction through low friction coatings, such as diamond like carbon (DLC), and optical reflectivity through coatings with contro

30、lled optical properties.Appropriate choice of coatings for particular applications depends on the mechanical and other functional requirements that arise. One factor that can be crucial in determining coating performance and lifetime is the residual stress that is generated by the deposition process

31、 and/or by thermal expansion mismatch between the coating and the substrate as the component is cooled from the processing temperature.This document describes the application of a simple experimental technique using the Stoney formula to analyse the coating induced bending of coupons, of known mecha

32、nical properties, to determine the residual stress in the coating. ISO 2017 All rights reserved vBS ISO 19674:2017Fine ceramics (advanced ceramics, advanced technical ceramics) Methods of test for ceramic coatings Determination of internal stress in ceramic coatings by application of the Stoney form

33、ula1 ScopeThis document specifies a method for the determination of the internal stress in thin ceramic coatings by application of the Stoney formula to the results obtained from measurement of the radius of curvature of coated strips or discs.2 Normative referencesThere are no normative references

34、in this document.3 Terms and definitionsNo terms and definitions are listed in this document.ISO and IEC maintain terminological databases for use in standardization at the following addresses: IEC Electropedia: available at h t t p :/ www .electropedia .org/ ISO Online browsing platform: available

35、at h t t p :/ www .iso .org/ obp4 PrincipleCoating stress often plays a major role in the performance of coated tools and machine parts. Different techniques have been developed for the determination of coating stress. The technique considered in this document calculates the stress from measurement

36、of the bowing of thin discs or strips of well-characterized materials of known thickness that have been coated on one side only. It is assumed that the deformation is elastic, i.e. if the coating were to be removed the substrate would return to its initial shape.Provided that the coating is thin com

37、pared to the thickness of the substrate (coating thickness 20 m) radii of curvature using optical techniques.Before measuring the initial profile, define a measuring range (length ), along the length a of the substrate (along a diameter for the disc).In order to avoid any edge effects, the measuring

38、 range should stop at a distance from the ends equal to at least 20 times the sample thickness.Make some reference marks, e.g. Vickers indentations, on the substrate, so that the final profile can be measured at the same location and in the same direction as the initial one. This procedure is essent

39、ial when the initial profile is somewhat different from a perfect circle.4 ISO 2017 All rights reservedBS ISO 19674:2017ISO 19674:2017(E)It is recommended that, where hardness indents are used as reference marks, indentations should be produced using a microhardness tester at a load of no greater th

40、an 1 kg.For measuring the profile, the sample shall lie freely, without any external stress. Place the strip on two supports, so that it overhangs each support by a quarter of its length; proceed similarly for a disc.NOTE In many cases, supporting the sample on its ends will have negligible effect u

41、pon the curvature. However, the use of supports will avoid problems with stability of the sample if one or both ends of the sample are not perpendicular to the sides.Especially for thin samples, ensure that the weight of the sample does not change its shape: turning the strip (or disc) over on the s

42、upports should leave the profile unchanged, except for the sign.In the case of optical microscopy, for each profile, measure the coordinates (xi, zi) of about 10 points distributed uniformly along the predefined measuring range. The ordinate zicorresponds to the vertical position of the microscope o

43、bjective for which the point xiof the surface of the sample is in the image plane. The focusing axis of the microscope shall be perpendicular to the surface to be coated, and especially to its longitudinal axis.The initial curvature can be disregarded in so far as it is very low ( ) usually allow th

44、e use of the simple method that consists of approximating the arc of the circle to a parabola, i.e. zxMMxMxR()=+ +01 22. The measured radius of curvature then is RMexp=122/( ).NOTE 2 The profile is close to a circle if the radius of curvature is approximately constant along the profile. For verifyin

45、g this, in the case where the profile is represented for instance by 10 points, i.e. (xi, zi; i = 1 to 10), compare the radii of curvature obtained on considering the points i = 1 to i = 5, then i = 3 to i = 8, and then i = 5 to i = 10. The various radii should be nearly equal (2(A.2)EXAMPLE For a l

46、ow strength steel substrate (y= 220 MPa and E = 220 GPa) 1 mm thick, plastic deformation occurs for radii of curvature lower than 0,5 m.NOTE In the case of coatings deposited with substrate heating and/or submitted to high temperature annealing, it is important to note that residual stresses exert t

47、heir effect on a material with yEratios different from those determined at room temperature. The yEratio is not constant with temperature increase, with yusually being observed to decrease more strongly than E with an increase in the testing temperature.8 ISO 2017 All rights reservedBS ISO 19674:201

48、7ISO 19674:2017(E)The order of magnitude to be chosen for hsis deduced through the Stoney formula, where R is in the order of 1 m, as shown in Formula (A.3):hvERhsssf2061= (A.3)The length a of the strip (usually between 40 mm and 80 mm) determines the length of the measured profile ( is a little sma

49、ller than a; see 7.1). For measurement uncertainty in the order of zalong the z direction, the condition to be verified is shown in Formula (A.4):aRz 10 (A.4)The width b (a/b 10) should be low in order to minimize the nonlinear effects relative to geometry. The corresponding condition is as follows see Formulae (A.5) and (A.6):bhR221 10 (A.4)The width b (a/b 10) should be low in order to minimize the nonlinear effects relative to geometry. The corresponding condition is