1、BRITISH STANDARD BS EN ISO 15720:2001 Metallic coatings Porosity tests Porosity in gold or palladium coatings on metal substrates by gel-bulk electrography The European Standard EN ISO 15720:2001 has the status of a British Standard ICS 25.220.40 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED
2、 BY COPYRIGHT LAWBS EN ISO 15720:2001 This British Standard, having been prepared under the direction of the Sector Committee for Materials and Chemicals, was published under the authority of the Standards Committee and comes into effect on 15 July 2001 BSI 07-2001 ISBN 0 580 37871 3 National forewo
3、rd This British Standard is the official English language version of EN ISO 15720:2001. It is identical with ISO 15720:2001. The UK participation in its preparation was entrusted to Technical Committee STI/37, Methods of test for metallic and related coatings including corrosion test, which has the
4、responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references Attention is drawn to the fact that CEN and CENELEC Standards normally include an annex which lists normative references to international publications with their cor
5、responding European publications. The British Standards which implement these international or European publications may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic
6、Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand th
7、e text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a fron
8、t cover, an inside front cover, the EN ISO title page, the EN ISO foreword page, the ISO title page, pages ii to v, a blank page, pages 1 to 11, the annex ZA page, an inside back cover and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued.
9、Amendments issued since publication Amd. No. Date CommentsEUROPEANSTANDARD NORMEEUROPENNE EUROPISCHENORM ENISO15720 April2001 ICS25.220.40 Englishversion MetalliccoatingsPorositytestsPorosityingoldorpalladium coatingsonmetalsubstratesbygelbulkelectrography(ISO 15720:2001) RevtementsmtalliquesEssaisd
10、eporositPorosit desrevtementsdoroudepalladiumsurmtauxpar lectrographieparglification(ISO15720:2001) MetallischeberzgePorenprfungenBestimmungdes PorenanteilsinGoldoderPalladiumberzgenauf metallischenGrundwerkstoffendurchGelElektrographie (ISO15720:2001) ThisEuropeanStandardwasapprovedbyCENon15April20
11、01. CENmembersareboundtocomplywiththeCEN/CENELECInternalRegulationswhichstipulatetheconditionsforgivingthisEurope an Standardthestatusofanationalstandardwithoutanyalteration.Uptodatelistsandbibliographicalreferencesconcernings uchnational standardsmaybeobtainedonapplicationtotheManagementCentreortoa
12、nyCENmember. ThisEuropeanStandardexistsinthreeofficialversions(English,French,German).Aversioninanyotherlanguagemadebytra nslation undertheresponsibilityofaCENmemberintoitsownlanguageandnotifiedtotheManagementCentrehasthesamestatusasthe official versions. CENmembersarethenationalstandardsbodiesofAus
13、tria,Belgium,CzechRepublic,Denmark,Finland,France,Germany,Greece, Iceland,Ireland,Italy,Luxembourg,Netherlands,Norway,Portugal,Spain,Sweden,SwitzerlandandUnitedKingdom. EUROPEANCOMMITTEEFORSTANDARDIZATION COMITEUROPENDENORMALISATION EUROPISCHESKOMITEEFRNORMUNG ManagementCentre:ruedeStassart,36B1050B
14、russels 2001CEN Allrightsofexploitationinanyformandbyanymeansreserved worldwideforCENnationalMembers. Ref.No.ENISO15720:2001EgaPe2 INESO5102702:01 Foreword ThetextoftheInternationalStandardISO15720:2001hasbeenpreparedbyTechnical CommitteeISO/TC107“Metallicandotherinorganiccoatings“incollaborationwit
15、hTechnical CommitteeCEN/TC262“Metallicandotherinorganiccoatings“,thesecretariatofwhichis heldbyBSI. ThisEuropeanStandardshallbegiventhestatusofanationalstandard,eitherbypublication ofanidenticaltextorbyendorsement,atthelatestbyOctober2001,andconflictingnational standardsshallbewithdrawnatthelatestby
16、October2001. AccordingtotheCEN/CENELECInternalRegulations,thenationalstandardsorganizationsof thefollowingcountriesareboundtoimplementthisEuropeanStandard:Austria,Belgium, CzechRepublic,Denmark,Finland,France,Germany,Greece,Iceland,Ireland,Italy, Luxembourg,Netherlands,Norway,Portugal,Spain,Sweden,S
17、witzerlandandtheUnited Kingdom. Endorsementnotice ThetextoftheInternationalStandardISO15720:2001wasapprovedbyCENasaEuropean Standardwithoutanymodification. NOTE:NormativereferencestoInternationalStandardsarelistedinannexZA(normative). ENISO15720:2001 Reference number ISO 15720:2001(E) INTERNATIONAL
18、STANDARD ISO 15720 First edition 2001-04-15 Metallic coatings Porosity tests Porosity in gold or palladium coatings on metal substrates by gel-bulk electrography Revtements mtalliques Essais de porosit Porosit des revtements dor ou de palladium sur mtaux par lectrographie par glification ENISO15720:
19、2001 ISO 02751:(1002)E ii ENISO15720:2001 ISO 02751:(1002)E ISO 1002 All rights rsedevre iii Contents Page Foreword.iv Introduction.v 1 Scope 1 2 Normative references 1 3 Terms and definitions .2 4 Apparatus .2 5 Reagent.4 6 Safety hazards4 7 Procedure .5 8 Examination7 9 Precision.7 10 Test report
20、8 Annex A (informative) Useful guidelines for examining samples 9 Annex B (informative) Significance and use 10 Bibliography11 ENISO15720:2001 ISO 02751:(1002)E iv ISO 1002 All rights rsedevre Foreword ISO (the International Organization for Standardization) is a worldwide federation of national sta
21、ndards 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 or
22、ganizations, 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 give
23、n in the ISO/IEC Directives, Part 3. 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 possibilit
24、y that some of the elements of this International Standard may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. International Standard ISO 15720 was prepared by Technical Committee ISO/TC 107, Metallic and other inorganic coatings, Sub
25、committee SC 7, Corrosion tests. Annexes A and B of this International Standard are for information only. ENISO15720:2001 ISO 02751:(1002)E ISO 1002 All rights rsedevre v Introduction This test method is an electrographic technique, “gel-bulk electrography.“ The specimen is made the anode in a cell
26、containing a solid or semi-solid electrolyte of gelatin, conducting salts and an indicator. Application of current to this cell results in the migration of base metal ions through continuous pores. Reaction of cations with an indicator gives rise to coloured reaction products (not to be confused wit
27、h corrosion products) at pore sites which may be counted through the clear gel. Individual spots are counted with the aid of a lense or low-power stereomicroscope. The test method is designed to show whether the porosity level is less than or greater than a given value which, from experience, is con
28、sidered by the user to be acceptable for the intended application. These porosity tests involve corrosion reactions in which the products delineate defect sites in coatings. Since the chemistry and properties of these products do not resemble those found in natural or service environments, these tes
29、ts can not be recommended for the prediction of the electrical performance of contacts unless correlation is first established with service experience. This test method is suitable for coatings containing 75 % or more of gold on substrates of silver, nickel, copper and its alloys that are commonly u
30、sed in electrical contacts. This test method is also suitable for coatings of 95 % or more of palladium on nickel, copper and its alloys, and for coatings of palladium-nickel alloy (75 % or more of palladium) on nickel, copper and its alloys. This test method is capable of detecting porosity or othe
31、r defects in gold or palladium coatings that could participate in substrate corrosion reactions. In addition, it can be used on contacts having complex geometry such as pin-socket contacts (although difficulty may be experienced in inspecting deep recesses). This test is considered destructive becau
32、se it reveals the presence of porosity by contaminating the surface with corrosion products and by it undercuts the corrodible metal at pore sites and at unplated areas. In addition, the surface is coated with a corrosive gel mixture which is difficult to remove completely. Any parts exposed to the
33、gel test shall not be placed in service. ENISO15720:2001 ENISO15720:2001 INTENRATIONAL TSANDADR ISO 02751:(1002)E ISO 1002 All rights rsedevre 1 Metallic coatings Porosity tests Porosity in gold or palladium coatings on metal substrates by gel-bulk electrography WARNING This International Standard d
34、oes not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this International Standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For specific hazard
35、 statements, see clause 6. 1 Scope This test method covers equipment and techniques for determining porosity in noble metal coatings, particularly electrodeposits of gold, palladium and palladium-nickel alloy (70 % to 90 % palladium) and clad metals used on electrical contacts. The gel-bulk procedur
36、e is not as sensitive to small pores and is more complex than porosity tests involving gaseous corrodants (see ISO 14647 and ISO 15721). It also involves more chemicals, preparation and auxiliary equipment. This test is intended to be used for quantitative descriptions of porosity (such as number of
37、 pores per unit area or per contact) only on measurement areas where coatings have a sufficiently low pore density such that the corrosion sites are well separated and can be readily resolved. As a general guideline this can be achieved for pore densities up to about 25/cm 2 . Other porosity testing
38、 methods are outlined in ISO 10308. Detailed critical reviews of porosity testing are also available. Other porosity test methods are described in ISO 12687, ISO 14647 and ISO 15721. 2 Normative references The following normative documents contain provisions which, through reference in this text, co
39、nstitute provisions of this International Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent e
40、ditions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards. ISO 2064, Metallic and other inorganic coatings Definitions and conventi
41、ons concerning the measurement of thickness. ISO 2079, Surface treatment and metallic coatings General classification of terms. ISO 2080, Electroplating and related processes Vocabulary. ISO 10308, Metallic coatings Review of porosity tests. ENISO15720:2001 ISO 02751:(1002)E 2 ISO 1002 All rights rs
42、edevre 3 Terms and definitions For the purposes of this International Standard, the terms and definitions given in ISO 2064, ISO 2079, ISO 2080 and ISO 10308 as well as the following apply. 3.1 decorations coloured reaction products emanating from the pores that provide visual contrast with the gel
43、medium NOTE While non-standard terms are deprecated, the term decorations has had long-standing use in differentiating between coloured pore indicators and true corrosion products. The term can be found in the technical literature. 3.2 metallic coatings Includes platings, claddings, or other metalli
44、c layers applied to the substrate NOTE The coatings can comprise a single metallic layer or a combination of metallic layers. 3.3 porosity The presence of any discontinuity, crack, or hole in the coating that exposes a different underlying metal 4 Apparatus 4.1 Test vessel, of glass, acrylic resin o
45、r other inert colourless transparent material. It shall have thin-walled flat sides and be of a size appropriate to the sample to be tested. 4.2 Power supply, rated at 0 A to 1 A and 0 V to 10 V dc; an electronically regulated, constant-current ( 5%) apparatus is preferred. 4.3 dc milliammeter. 4.4
46、Separate dc voltmeter. 4.5 Cathode material, in the form of plain expanded foil or wire and made of titanium and coated with platinum, gold or other inert coating. Alternatively, platinum, gold or other inert metals may be used. The cathode and specimen (anode) areas shall be approximately the same.
47、 Additional, gold or platinum wires for cathode and anode are needed for that portion of the electrical connection that is in the reagent solution. If small alligator clips are used to secure the lead wires to the cathode and anode they shall be heavily gold-plated so as to be entirely free of poros
48、ity. A variation of this procedure, suitable for samples with relatively few pores, is to use a second identical test sample as the cathode. The test can be run with current first in the forward, then in the reverse direction so that the porosity in both samples may be determined. Figure 1 is a diagram of the test cell setup. NOTE A commonly used alternative cell design incorporates the cathode as part of the
