SIST EN ISO 15720:2002

Metallic coatings - Porosity tests - Porosity in gold or palladium coatings on metal substrates by gel-bulk electrography (ISO 15720:2001)

Metallische Überzüge - Porenprüfungen - Bestimmung des Porenanteils in Gold- oder Palladiumüberzügen auf metallischen Grundwerkstoffen durch Gel-Elektrographie (ISO 15720:2001)

Revetements métalliques - Essais de porosité - Porosité des revetements d'or ou de palladium sur métaux par électrographie par gélification (ISO 15720:2001)

Cette méthode d'essai couvre les équipements et techniques destinés à déterminer la porosité dans des revêtements de métaux nobles, particulièrement des dépôts électrolytiques d'or, de palladium et d'alliage palladium-nickel (70 % à 90 % de palladium) et dans des métaux plaqués utilisés sur les contacts électriques.  Le mode opératoire par gélification n'est pas aussi sensible aux petits pores et est plus complexe que des essais de porosité impliquant des corrodants gazeux (voir l'ISO 14647 et l'ISO 15721). Il implique aussi davantage de produits chimiques, de préparation et d'équipements auxiliaires.  Cet essai est destiné à être utilisé pour des descriptions quantitatives de la porosité (comme le nombre de pores par unité de surface ou par contact) uniquement sur les zones de mesurage où les revêtements ont une densité de pores suffisamment faible, de sorte que les sites de corrosion sont bien séparés et peuvent être facilement séparés. À titre de ligne directrice générale, il peut s'appliquer pour les densités de pores allant jusqu'à environ 25/cm2.  D'autres méthodes d'essai de porosité sont indiquées dans l'ISO 10308. Des revues critiques détaillées d'essais de porosité sont également disponibles. D'autres méthodes d'essai de porosité sont décrites dans l'ISO 12687, l'ISO 14647 et l'ISO 15721.

Kovinske prevleke - Preskus poroznosti - Ugotavljanje poroznosti zlatih ali paladijskih prevlek na kovinskih podlagah z gelsko elektrografijo (ISO 15720:2001)

General Information

• Status: Published
• Publication Date: 28-Feb-2002
• ICS: 25.220.40 - Metallic coatings
• Technical Committee: IPKZ - Protection of metals against corrosion
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Mar-2002
• Due Date: 01-Mar-2002
• Completion Date: 01-Mar-2002
• Ref Project: EN ISO 15720:2001 - Metallic coatings - Porosity tests - Porosity in gold or palladium coatings on metal substrates by gel-bulk electrography (ISO 15720:2001)

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN ISO 15720:2002
01-marec-2002
Kovinske prevleke - Preskus poroznosti - Ugotavljanje poroznosti zlatih ali
paladijskih prevlek na kovinskih podlagah z gelsko elektrografijo (ISO 15720:2001)
Metallic coatings - Porosity tests - Porosity in gold or palladium coatings on metal
substrates by gel-bulk electrography (ISO 15720:2001)
Metallische Überzüge - Porenprüfungen - Bestimmung des Porenanteils in Gold- oder
Palladiumüberzügen auf metallischen Grundwerkstoffen durch Gel-Elektrographie (ISO
15720:2001)
Revetements métalliques - Essais de porosité - Porosité des revetements d'or ou de
palladium sur métaux par électrographie par gélification (ISO 15720:2001)
Ta slovenski standard je istoveten z: EN ISO 15720:2001
ICS:
25.220.40 Kovinske prevleke Metallic coatings
SIST EN ISO 15720:2002 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 15720:2002

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SIST EN ISO 15720:2002
EUROPEAN STANDARD
EN ISO 15720
NORME EUROPÉENNE
EUROPÄISCHE NORM
April 2001
ICS 25.220.40
English version
Metallic coatings - Porosity tests - Porosity in gold or palladium
coatings on metal substrates by gel-bulk electrography (ISO
15720:2001)
Revêtements métalliques - Essais de porosité - Porosité Metallische Überzüge - Porenprüfungen - Bestimmung des
des revêtements d'or ou de palladium sur métaux par Porenanteils in Gold- oder Palladiumüberzügen auf
électrographie par gélification (ISO 15720:2001) metallischen Grundwerkstoffen durch Gel-Elektrographie
(ISO 15720:2001)
This European Standard was approved by CEN on 15 April 2001.
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 alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the Management Centre or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,
Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2001 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 15720:2001 E
worldwide for CEN national Members.

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SIST EN ISO 15720:2002
Page 2
EN ISO 15720:2001
Foreword
The text of the International Standard ISO 15720:2001 has been prepared by Technical
Committee ISO/TC 107 "Metallic and other inorganic coatings" in collaboration with Technical
Committee 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 2001, and conflicting national
standards shall be withdrawn at the latest by October 2001.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of
the following countries are bound to implement this European Standard: Austria, Belgium,
Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy,
Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United
Kingdom.
Endorsement notice
The text of the International Standard ISO 15720:2001 was approved by CEN as a European
Standard without any modification.
NOTE: Normative references to International Standards are listed in annex ZA (normative).

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SIST EN ISO 15720:2002
Page 3
EN ISO 15720:2001
Annex ZA (normative)
Normative references to international publications
with their relevant European publications
This European Standard incorporates by dated or undated reference, provisions from other
publications. These normative references are cited at the appropriate places in the text and the
publications are listed hereafter. For dated references, subsequent amendments to or revisions
of any of these publications apply to this European Standard only when incorporated in it by
amendment or revision. For undated references the latest edition of the publication referred to
applies (including amendments).
NOTE Where an International Publication has been modified by common modifications,
indicated by (mod.), the relevant EN/HD applies.
Publication Year Title EN Year
ISO 10308 1995 Metallic coatings - Review of porosity EN ISO 10308 1997
tests

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SIST EN ISO 15720:2002

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SIST EN ISO 15720:2002
INTERNATIONAL ISO
STANDARD 15720
First edition
2001-04-15
Metallic coatings — Porosity tests —
Porosity in gold or palladium coatings on
metal substrates by gel-bulk electrography
Revêtements métalliques — Essais de porosité — Porosité des
revêtements d'or ou de palladium sur métaux par électrographie par
gélification
Reference number
ISO 15720:2001(E)
©
ISO 2001

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SIST EN ISO 15720:2002
ISO 15720:2001(E)
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ii © ISO 2001 – All rights reserved

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SIST EN ISO 15720:2002
ISO 15720:2001(E)
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 hazards.4
7 Procedure .5
8 Examination.7
9 Precision.7
10 Test report .8
Annex A (informative) Useful guidelines for examining samples .9
Annex B (informative) Significance and use .10
Bibliography.11
© ISO 2001 – All rights reserved iii

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SIST EN ISO 15720:2002
ISO 15720:2001(E)
Foreword
ISO (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 technical 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 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 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 possibility 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, Subcommittee SC 7, Corrosion tests.
Annexes A and B of this International Standard are for information only.
iv © ISO 2001 – All rights reserved

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SIST EN ISO 15720:2002
ISO 15720:2001(E)
Introduction
This test method is an electrographic technique, "gel-bulk electrography." The specimen is made the anode in a
cell 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 with 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 considered 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
tests 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 used 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 other 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 because 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 gel
test shall not be placed in service.
© ISO 2001 – All rights reserved v

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SIST EN ISO 15720:2002

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SIST EN ISO 15720:2002
INTERNATIONAL STANDARD ISO 15720:2001(E)
Metallic coatings — Porosity tests — Porosity in gold or palladium
coatings on metal substrates by gel-bulk electrography
WARNING — This International Standard does 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 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 procedure 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 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
2
densities up to about 25/cm .
Other porosity testing 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, constitute 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 editions 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 conventions 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.
© ISO 2001 – All rights reserved 1

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SIST EN ISO 15720:2002
ISO 15720:2001(E)
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 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 metallic 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 or 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 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 cat
...