1、|BRITISH STANDARDBS ISO14647:2000ICS 25.220.40NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWMetallic coatings Determination ofporosity on goldcoatings on metallicsubstrates Nitric acid vapour testBS EN ISO 14647:2016(ISO 14647:2000)BS EN ISO 14647:2016ISBN 978 0 580 90539 1Am
2、endments/corrigenda issued since publicationDate Comments31 May 2016 This corrigendum renumbers BS ISO 14647:2000 as BS EN ISO 14647:2016.This British Standard, having been prepared under the direction of the Sector Committee for Materials and Chemicals, was published under the authority of the Stan
3、dards Committee and comes into effect on 15 May 2000 The British Standards Institution 2016. Published by BSI Standards Limited 2016National forewordThis British Standard is the UK implementation of EN ISO 14647:2016. It is identical to ISO 14647:2000. It supersedes BS ISO 14647:2000 which is withdr
4、awn.The UK participation in its preparation was entrusted to Technical Committee STI/33, Electrodeposited and related coatings.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 o
5、f a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 14647 April 2016 ICS 25.220.40 English Version Metallic coatings - Determination of porosity in go
6、ld coatings on metal substrates - Nitric acid vapour test (ISO 14647:2000) Revtements mtalliques - Dtermination de la porosit des revtements dor sur les substrats de mtal - Essai la vapeur dacide nitrique (ISO 14647:2000) Metallische berzge - Bestimmung der Porositt in Goldbeschichtungen auf Metalls
7、ubstraten - Salpetersure-Dampftest (ISO 14647:2000) This European Standard was approved by CEN on 2 April 2016. 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 alt
8、eration. 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 ma
9、de 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, Esto
10、nia, 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 andUnited Kingdom. EUROPEAN COMMITTEE FOR STAND
11、ARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2016 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 14647:2016 EBS EN ISO 14647:2016EN I
12、SO 14647:2016 (E)EN ISO 14647:2016 (E) 3 European foreword The text of ISO 14647:2000 has been prepared by Technical Committee ISO/TC 107 “Metallic and other inorganic coatings” of the International Organization for Standardization (ISO) and has been taken over as EN ISO 14647:2016 by Technical Comm
13、ittee CEN/TC 262 “Metallic and other inorganic coatings” the secretariat of which is held by BSI. 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 October 2016, and conflicting national standards s
14、hall be withdrawn at the latest by October 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. According to the CEN-CENELEC Internal
15、 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, Irela
16、nd, 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 14647:2000 has been approved by CEN as EN ISO 14647:2016 without any modification. ISO 14
17、647:2000(E)iiiContents PageForeword.ivIntroduction.v1 Scope 12 Normative references 13 Terms and definitions .24 Apparatus .25 Reagent.36 Safety 37 Procedure .38 Precision.59 Test report 5Annex A (informative) Time of exposure to nitric acid vapour.6Annex B (informative) Procedure recommended for av
18、oiding the use of chlorinated hydrocarbons .7Bibliography8BS EN ISO 14647:2016ISO 14647:2000(E)ISO 14647:2000(E)iv ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISOmember bodies). The work of preparing International Standards
19、 is normally carried out through ISO technicalcommittees. Each member body interested in a subject for whichatechnical committee has been established hasthe right to be represented on that committee. International organizations, governmental and non-governmental, inliaison with ISO, also take part i
20、n the work. ISO collaborates closely with the International ElectrotechnicalCommission (IEC) on all matters of electrotechnical standardization.International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3.Draft International Standards adopted by the techni
21、cal committees are circulated to the member bodies for voting.Publication as an International Standard requires approval by at least 75 % of the member bodies castingavote.Attention is drawn to the possibility that some of the elements of this International Standard may be the subject ofpatent right
22、s. ISO shall not be held responsible for identifying any or all such patent rights.International Standard ISO 14647 was prepared by Technical Committee ISO/TC 107, Metallic and other inorganiccoatings, Subcommittee SC 7, Corrosion tests.Annexes A and B of this International Standard are for informat
23、ion only.BS EN ISO 14647:2016ISO 14647:2000(E)ISO 14647:2000(E)vIntroductionGold coatings are often specified for the contacts of separable electrical connectors and other devices.Electrodeposits are the form of gold that is most used on contacts, although it is also employed as clad metal andas wel
24、dments on the contact surface. The intrinsic nobility of gold enables it to resist the formation of insulatingoxide films that could interfere with reliable contact operation.In order that the nobility of gold be assured, porosity, cracks, and other defects in the coating that expose basemetal subst
25、rates and underplates should be minimal or absent, except in those cases where it is feasible to use thecontacts in structures that shield the surface from the environment or where corrosion inhibiting surface treatmentsfor the deposit are employed. The level of porosity in the coating that may be t
26、olerable depends on the severity ofthe environment to the underplate or substrate, design factors for the contact device like the force with which it ismated, circuit parameters, and the reliability of contact operation that it is necessary to maintain. Also, whenpresent, the location of pores on th
27、e surface is important. If the pores are few in number and are outside the zoneof contact of the mating surfaces, their presence can often be tolerated.Methods for determining pores on a contact surface are most suitable if they enable their precise location andnumbers to be determined. Contact surf
28、aces are often curved or irregular in shape, and test methods should besuitable for them. In addition, the severity of porosity-determining tests may vary. The test method described in thisInternational Standard is regarded as severe.The relationship of porosity levels revealed by particular tests t
29、o contact behavior should be made by the user ofthese tests through practical experience or by judgement. Thus, absence of porosity in the coating may be arequirement for some applications, whileafew pores on the critical surfaces may be acceptable for another. Suchacceptance (or pass-fail) criteria
30、 should be part of the product specification for the particular product or partrequiring the porosity test.The test method described is highly sensitive and is capable of detecting virtually all porosity or other defects ingold coatings that could participate in substrate corrosion reactions. It is
31、rapid, simple and inexpensive. In addition,it can be used on contacts having complex geometry such as pin-socket contacts. However, it is preferred thatdeeply recessed sockets are opened to expose their critical surfaces prior to testing.The test method described is considered destructive in that it
32、 reveals the presence of porosity by contaminating thesurface with corrosion products and by undercutting the coating at pore sites or at the boundaries of unplatedareas. Any parts exposed to these tests should not be placed in service.The test described involves corrosion reactions in which the pro
33、ducts delineate defect sites in coatings. Since thechemistry, and properties of these products may not resemble those found in natural or service environments,these tests are not recommended for prediction of the electrical performance of contacts unless correlation is firstestablished with service
34、experience.The test method described employs nitric acid (HNO3) vapour at low relative humidity. Reaction of the gas mixturewith a corrodible base metal at pore sites produces reaction products that appear as discrete spots on the goldsurface. Individual spots are counted with the aid of a lens or l
35、ow-power stereomicroscope.The test method described is intended to be used for quantitative descriptions of porosity (such as number of poresper unit area or per contact) only on coatings that have a pore density sufficiently low that the corrosion sites arewell separated and can be readily resolved
36、. As a general guideline this can be achieved for pore densities up toabout 100 per square centimetre or per 100 contacts. Above this value the tests are useful for the qualitativedetection and comparison of porosity.BS EN ISO 14647:2016ISO 14647:2000(E)INTERNATIONAL STANDARD ISO 14647:2000(E)1Metal
37、lic coatings Determination of porosity in gold coatings onmetal substrates Nitric acid vapour testWARNING: This International Standard does not purport to address all of the safety problems, if any,associated with its use. It is the responsibility of the user of this International Standard to establ
38、ishappropriate safety and health practices and to determine the applicability of regulatory limitations prior touse. Specific precautionary measures are given in clause 6 and in 7.4, note 2.1 ScopeThis International Standard specifies equipment andamethod for using nitric acid vapour to determine po
39、rosity ingold coatings, particularly electrodeposits and clad metals used on electrical contacts.This method is designed to show whether the porosity level is less than or greater than some value that, byexperience, is considered by the user to be acceptable for the intended application.It is suitab
40、le for inlays or claddings containing 75 % or more of gold, for electrodeposits containing 95 % or more ofgold or for substrates of copper, nickel and their alloys that are commonly used in electrical contacts.The nitric acid vapour test is too severe to be used for gold coatings less than 0,6 G6dm
41、thick. It is also not suitable forcoatings that are less noble than gold or platinum, such as palladium and its alloys, or gold-flashed palladium andits alloys.Several other porosity testing methods are described in ISO 10308 and in the literature (see e.g. Bibliography, 1and 2).2 Normative referenc
42、esThe following normative documents contain provisions which, through reference in this text, constitute provisions ofthis International Standard. For dated references, subsequent amendments to, or revisions of, any of thesepublications do not apply. However, parties to agreements based on this Inte
43、rnational Standard are encouraged toinvestigate the possibility of applying the most recent editions of the normative documents indicated below. Forundated references, the latest edition of the normative document referred to applies. Members of ISO and IECmaintain registers of currently valid Intern
44、ational Standards.ISO 2064, Metallic and other inorganic coatings Definitions and conventions concerning the measurement ofthickness.ISO 2079, Surface treatment and metallic coatings General classification of terms.ISO 2080, Electroplating and related processes Vocabulary.ISO 10308, Metallic coating
45、s Review of porosity tests.BS EN ISO 14647:2016ISO 14647:2000(E)2 3 Terms and definitionsFor the purposes of this International Standard, the terms and definitions given in ISO 2079, ISO 2080, ISO 10308and the following apply.3.1corrosion productsthose reaction products emanating from the pores that
46、 protrude from, or are otherwise attached to, the coatingsurface after a vapour test exposure3.2significant surfacesee ISO 2064:1996, 3.1NOTE It is essential that the significant surfaces or measuring areas of the part to be tested are indicated on the drawing ofthe part or by provision of suitably
47、marked samples.3.3measuring areasee ISO 2064:1996, 3.23.4metallic coatingselectrodeposits, claddings, or other metallic layers applied to the substrateNOTE The coating can comprise a single metallic layer or a combination of metallic layers.3.5porositypresence of any discontinuity, crack, or hole in
48、 the coating that exposes a different underlying metal3.6underplatemetallic coating layer between the substrate and the topmost layer or layersNOTE The thickness of an underplate is usually greater than 0,8 G6dm.4 Apparatus4.1 Test chamberThis may be any convenient size glass vessel capable of being
49、 sealed with a glass lid, such as a glass desiccatorof 9 l to 12 l capacity. The ratio of the air space in the chamber (in cubic centimetres) to the nitric acid surface area(in square centimetres) shall be no greater than 25:1.4.2 Specimen holders or supportsSupports or hangers shall be made from glass, polytetrafluoroethylene or other inert materials. It is essential thatthe holders are so designed, and the specimens so arra
