SIST EN ISO 15721:2002

Metallic coatings - Porosity tests - Porosity in gold or palladium coatings by sulfurous acid/sulfur dioxide vapour (ISO 15721:2001)

Metallische Überzüge - Porenprüfungen - Bestimmung des Porenanteils in Gold- oder Palladiumüberzügen mit schwefliger Säure/Schwefeldioxiddampf (ISO 15721:2001)

Revetements métalliques - Essais de porosité - Porosité des revetements d'or ou de palladium par essai a l'acide sulfureux/vapeur de dioxide de soufre (ISO 15721:2001)

La présente méthode d'essai couvre les équipements et techniques destinés à déterminer la porosité des revêtements d'or ou de palladium, particulièrement des dépôts électrolytiques et des métaux plaqués utilisés sur des contacts électriques.  La méthode d'essai a pour objet de vérifier si le niveau de porosité est inférieur ou supérieur à une certaine valeur qui, par expérience, est considérée comme acceptable par l'utilisateur pour l'application prévue.  Cet essai de porosité implique des réactions de corrosion dans lesquelles les produits mettent en évidence des sites de défauts dans des revêtements. Étant donné que la chimie et les propriétés de ces produits peuvent ne pas ressembler à celles rencontrées dans des environnements naturels ou de service, cet essai ne peut être recommandé pour prédire la performance électrique des contacts, à moins qu'une corrélation ne soit préalablement établie avec l'expérience de service.  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) sur des revêtements présentant une densité de pores suffisamment faible pour que les sites de corrosion soient bien séparés et puissent être facilement analysés. En règle générale, il peut s'appliquer pour des densités de pores jusqu'à environ 100/cm2. Pour des valeurs de densité plus grande, les essais sont utilisés pour une détection qualitative et des comparaisons de la porosité.  De nombreuses autres méthodes d'essai de porosité sont décrites dans la littérature technique 151161. D'autres méthodes d'essai de porosité sont données dans l'ISO 12308, l'ISO 12687, l'ISO 14647 et l'ISO 15720.

Kovinske prevleke - Preskus poroznosti - Ugotavljanje poroznosti zlatih ali paladijskih prevlek s paro H2SO3/SO2 (ISO 15721:2001)

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 15721:2001 - Metallic coatings - Porosity tests - Porosity in gold or palladium coatings by sulfurous acid/sulfur dioxide vapour (ISO 15721:2001)

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN ISO 15721:2002
01-marec-2002
Kovinske prevleke - Preskus poroznosti - Ugotavljanje poroznosti zlatih ali
paladijskih prevlek s paro H2SO3/SO2 (ISO 15721:2001)
Metallic coatings - Porosity tests - Porosity in gold or palladium coatings by sulfurous
acid/sulfur dioxide vapour (ISO 15721:2001)
Metallische Überzüge - Porenprüfungen - Bestimmung des Porenanteils in Gold- oder
Palladiumüberzügen mit schwefliger Säure/Schwefeldioxiddampf (ISO 15721:2001)
Revetements métalliques - Essais de porosité - Porosité des revetements d'or ou de
palladium par essai a l'acide sulfureux/vapeur de dioxide de soufre (ISO 15721:2001)
Ta slovenski standard je istoveten z: EN ISO 15721:2001
ICS:
25.220.40 Kovinske prevleke Metallic coatings
SIST EN ISO 15721:2002 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 15721:2002

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SIST EN ISO 15721:2002
EUROPEAN STANDARD
EN ISO 15721
NORME EUROPÉENNE
EUROPÄISCHE NORM
April 2001
ICS 25.220.40
English version
Metallic coatings - Porosity tests - Porosity in gold or palladium
coatings by sulfurous acid/sulfur dioxide vapour (ISO
15721:2001)
Revêtements métalliques - Essais de porosité - Porosité Metallische Überzüge - Porenprüfungen - Bestimmung des
des revêtements d'or ou de palladium par essai à l'acide Porenanteils in Gold- oder Palladiumüberzügen mit
sulfureux/vapeur de dioxide de soufre (ISO 15721:2001) schwefliger Säure/Schwefeldioxiddampf (ISO 15721:2001)
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 15721:2001 E
worldwide for CEN national Members.

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SIST EN ISO 15721:2002
Page 2
EN ISO 15721:2001
Foreword
The text of the International Standard ISO 15721:2001 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 15721:2001 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 15721:2002
Page 3
EN ISO 15721:2001
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 2064 1996 Metallic and other inorganic coatings - EN ISO 2064 2000
Definitions and conventions concerning
the measurement of thickness
ISO 10308 1995 Metallic coatings - Review of porosity EN ISO 10308 1997
tests

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SIST EN ISO 15721:2002

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SIST EN ISO 15721:2002
INTERNATIONAL ISO
STANDARD 15721
First edition
2001-04-15
Metallic coatings — Porosity tests —
Porosity in gold or palladium coatings by
sulfurous acid/sulfur dioxide vapour
Revêtements métalliques — Essais de porosité — Porosité des
revêtements d'or ou de palladium par essai à l'acide sulfureux/vapeur de
dioxyde de soufre
Reference number
ISO 15721:2001(E)
©
ISO 2001

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SIST EN ISO 15721:2002
ISO 15721:2001(E)
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ii © ISO 2001 – All rights reserved

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SIST EN ISO 15721:2002
ISO 15721:2001(E)
Contents Page
Foreword.iv
Introduction.v
1 Scope .1
2 Normative references .1
3 Terms and definitions .2
4 Apparatus .2
5 Reagents.2
6 Safety hazards.2
7 Procedure .3
8 Examination.4
9 Precision.5
10 Test report .5
Annex A (informative) Significance and use .6
Bibliography.7
© ISO 2001 – All rights reserved iii

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SIST EN ISO 15721:2002
ISO 15721:2001(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 15721 was prepared by Technical Committee ISO/TC 107, Metallic and other inorganic
coatings, Subcommittee SC 7, Corrosion tests.
Annex A of this International Standard is for information only.
iv © ISO 2001 – All rights reserved

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SIST EN ISO 15721:2002
ISO 15721:2001(E)
Introduction
The test method makes use of concentrated sulfurous acid (H SO ), which emits sulfur dioxide (SO )gas
2 3 2
according to the equilibrium reaction:
H SO =SO +H O
2
2 3 2
WARNING — The sulfur dioxide gas that is released by the sulfurous acid is toxic, corrosive and irritating.
The sulfurous acid shall only be handled and used in a fume cupboard. Prior to starting the test, suitable
preparation shall be made to dispose of approximately 200 ml to 500 ml of sulfurous acid used in the test.
[4]
The procedure is similar to one first proposed by Lee and Ternowski . Exposure periods may vary, depending
upon the degree of porosity to be revealed. Reaction of the gas with a corrodible base metal at pore sites produces
reaction products that appear as discrete spots on the gold or palladium surface. Individual spots are counted with
the aid of a lens or low-power stereomicroscope.
This test method is suitable for coatings containing 95 % or more of gold or palladium on substrates of copper,
nickel and their alloys which are commonly used in electrical contacts.
This test is considered destructive because it reveals the presence of porosity by contaminating the surface with
corrosion products and it undercuts the coating at pore sites or at the boundaries of the unplated areas. Any parts
exposed to this test shall not be placed in service.
The present test method is capable of detecting virtually all porosity or other defects that could participate in
corrosion reactions with the substrate or underplate. The test is rapid, simple and inexpensive. In addition, it can be
used on contacts with a complex geometry such as pin-sockets (it may be useful to open contact structures with
deep recesses to permit reaction of the sulfur dioxide with the interior significant surfaces).
© ISO 2001 – All rights reserved v

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SIST EN ISO 15721:2002

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SIST EN ISO 15721:2002
INTERNATIONAL STANDARD ISO 15721:2001(E)
Metallic coatings — Porosity tests — Porosity in gold or palladium
coatings by sulfurous acid/sulfur dioxide vapour
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 methods for determining the porosity of gold or palladium coatings,
particularly electrodeposits and clad metals used on electrical contacts.
It is designed to show whether the porosity level is less than or greater than a given value which by experience is
considered by the user to be acceptable for the intended application.
This porosity test involves corrosion reactions in which the products delineate defect sites in coatings. Since the
chemistry and properties of these products may not resemble those found in natural or service environments this
test cannot be recommended for the prediction of the electrical performance of contacts unless correlation is first
established with service experience.
This test is intended to be used for quantitative descriptions of porosity (such as number of pores per unit area or
per contact) on coatings that have a sufficiently low pore density so that the corrosion sites are well separated and
2
can be readily resolved. As a general guideline this can be achieved for pore densities up to about 100/cm .Above
this value the tests are useful for the qualitative detection and comparisons of porosity.
[5],[6]
A variety of other porosity testing methods are described
...