Metallic and other inorganic coatings - Electrodeposited silver and silver alloy coatings for engineering purposes - Specification and test methods (ISO 4521:2008)

This International Standard specifies requirements for electro plated silver and silver alloy coatings for electrical, electronic and other engineering applications, including test methods. Engineering applications are defined as those in which the coating essentially serves a non-decorative purpose. Although this International Standard does not specify the condition, finish or surface roughness of the basis material prior to electroplating, the appearance and serviceability of electroplated silver and silver alloy coatings depend on the condition of the basis material. It is essential that the purchaser specifies the surface finish and roughness of the basis material in order to conform to the product requirements.

Metallische Überzüge - Galvanische Silber- und Silberlegierungs-Überzüge für technische Zwecke - Anforderungen und Prüfverfahren (ISO 4521:2008)

Diese Internationale Norm legt Anforderungen an galvanische Silber- und Silberlegierungs-Überzüge für elektrische, elektronische und andere technische Anwendungen fest, einschließlich der Prüfverfahren die angewandt werden müssen um nachzuweisen, dass die Anforderungen an die Überzüge zufriedenstellend sind. Technische Zwecke werden als solche definiert, bei denen die Überzüge im wesentlichen zu nicht dekorativen Zwecken dienen.
Diese Internationale Norm legt Beschaffenheit, Finish und Rauheit des Grundmaterials vor der elektrolytischen Abscheidung nicht fest. Da aber das Aussehen und die Brauchbarkeit von galvanischen Silberübezügen von der Beschaffenheit des Grundmaterials abhängt, sollte eine Vereinbarung zwischen den interessierten Parteien getroffen werden, dahingehend, dass Finish und Rauheit des Grundmaterials für die galvanische Metallabscheidung zufriedenstellend sind [siehe 4.1c) und 4.1e)].  
Diese Internationale Norm gilt nicht für Verbindungselemente mit Gewinden (siehe ISO 4042) oder für Überzüge auf Blechen und Bändern in unbearbeiteter Form.

Revêtements métalliques et autres revêtements inorganiques - Dépôts électrolytiques d'argent et d'alliages d'argent pour applications industrielles - Spécifications et méthodes d'essai (ISO 4521:2008)

L'ISO 4521:2008 spécifie des exigences pour les dépôts électrolytiques d'argent et d'alliages d'argent destinés à des applications électriques, électroniques ou à d'autres applications industrielles et indique des méthodes d'essai. Les applications industrielles sont celles pour lesquelles le dépôt assure essentiellement une fonction non décorative.
Bien que l'ISO 4521:2008 ne spécifie pas l'état initial, la finition ou la rugosité de surface du matériau de base avant le dépôt électrolytique, l'aspect et l'aptitude à l'usage des dépôts électrolytiques d'argent et d'alliages d'argent dépendent de l'état du matériau de base. Il est essentiel que l'acheteur spécifie la finition de surface et la rugosité du matériau de base afin de se conformer aux exigences du produit.
L'ISO 4521:2008 ne s'applique pas aux revêtements des filetages de vis ni à ceux des feuilles, bandes ou fils sous forme non-façonnée.

Kovinske in druge anorganske prevleke - Galvanske prevleke srebra in srebrovih zlitin za tehnične namene - Specifikacija in preskusne metode (ISO 4521:2008)

General Information

Status
Published
Publication Date
05-Oct-2008
Withdrawal Date
05-Apr-2007
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
10-Sep-2008
Due Date
15-Nov-2008
Completion Date
06-Oct-2008

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Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN ISO 4521:2008
01-november-2008
.RYLQVNHLQGUXJHDQRUJDQVNHSUHYOHNH*DOYDQVNHSUHYOHNHVUHEUDLQVUHEURYLK
]OLWLQ]DWHKQLþQHQDPHQH6SHFLILNDFLMDLQSUHVNXVQHPHWRGH ,62

Metallic and other inorganic coatings - Electrodeposited silver and silver alloy coatings

for engineering purposes - Specification and test methods (ISO 4521:2008)
Metallische Überzüge - Galvanische Silber- und Silberlegierungs-Überzüge für
technische Zwecke - Anforderungen und Prüfverfahren (ISO 4521:2008)

Revêtements métalliques et autres revêtements inorganiques - Dépôts électrolytiques

d'argent et d'alliages d'argent pour applications industrielles - Spécifications et méthodes

d'essai (ISO 4521:2008)
Ta slovenski standard je istoveten z: EN ISO 4521:2008
ICS:
25.220.40 Kovinske prevleke Metallic coatings
SIST EN ISO 4521:2008 en

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN ISO 4521:2008
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SIST EN ISO 4521:2008
EUROPEAN STANDARD
EN ISO 4521
NORME EUROPÉENNE
EUROPÄISCHE NORM
September 2008
ICS 25.220.40
English Version
Metallic and other inorganic coatings - Electrodeposited silver
and silver alloy coatings for engineering purposes - Specification
and test methods (ISO 4521:2008)

Revêtements métalliques et autres revêtements Metallische Überzüge - Galvanische Silber- und

inorganiques - Dépôts électrolytiques d'argent et d'alliages Silberlegierungs-Überzüge für technische Zwecke -

d'argent pour applications industrielles - Spécifications et Anforderungen und Prüfverfahren (ISO 4521:2008)

méthodes d'essai (ISO 4521:2008)
This European Standard was approved by CEN on 24 August 2008.

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 CEN 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 CEN Management Centre has the same status as the

official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,

France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,

Romania, Slovakia, Slovenia, 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

© 2008 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 4521:2008: E

worldwide for CEN national Members.
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SIST EN ISO 4521:2008
EN ISO 4521:2008 (E)
Contents Page

Foreword..............................................................................................................................................................3

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SIST EN ISO 4521:2008
EN ISO 4521:2008 (E)
Foreword

This document (EN ISO 4521:2008) 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 March 2009, and conflicting national standards shall be withdrawn at

the latest by March 2009.

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 Regulations, the national standards organizations of the following

countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech

Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,

Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,

Sweden, Switzerland and the United Kingdom.
Endorsement notice

The text of ISO 4521:2008 has been approved by CEN as a EN ISO 4521:2008 without any modification.

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SIST EN ISO 4521:2008
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SIST EN ISO 4521:2008
INTERNATIONAL ISO
STANDARD 4521
Second edition
2008-09-01
Metallic and other inorganic coatings —
Electrodeposited silver and silver alloy
coatings for engineering purposes —
Specification and test methods
Revêtements métalliques et autres revêtements inorganiques — Dépôts
électrolytiques d'argent et d'alliages d'argent pour applications
industrielles — Spécifications et méthodes d'essai
Reference number
ISO 4521:2008(E)
ISO 2008
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SIST EN ISO 4521:2008
ISO 4521:2008(E)
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© ISO 2008

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,

electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or

ISO's member body in the country of the requester.
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Published in Switzerland
ii © ISO 2008 – All rights reserved
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SIST EN ISO 4521:2008
ISO 4521:2008(E)
Contents Page

Foreword............................................................................................................................................................ iv

Introduction ........................................................................................................................................................ v

1 Scope ..................................................................................................................................................... 1

2 Normative references ........................................................................................................................... 1

3 Terms and definitions........................................................................................................................... 2

4 Information to be supplied by the purchaser to the electroplater................................................... 2

4.1 Essential information ........................................................................................................................... 2

4.2 Additional information.......................................................................................................................... 3

5 Designation ........................................................................................................................................... 3

5.1 General................................................................................................................................................... 3

5.2 Designation specifications .................................................................................................................. 4

5.3 Designation of the basis material ....................................................................................................... 4

5.4 Designation of heat treatment requirements ..................................................................................... 4

5.5 Examples of designations ................................................................................................................... 5

6 Requirements ........................................................................................................................................ 5

6.1 General................................................................................................................................................... 5

6.2 Appearance ........................................................................................................................................... 5

6.3 Thickness .............................................................................................................................................. 6

6.4 Porosity.................................................................................................................................................. 6

6.5 Accelerated corrosion testing ............................................................................................................. 6

6.6 Composition .......................................................................................................................................... 6

6.7 Stress-relief heat treatment prior to electroplating........................................................................... 6

6.8 Hydrogen-embrittlement-relief heat treatment after electroplating................................................. 6

6.9 Adhesion................................................................................................................................................ 7

6.10 Electrical properties ............................................................................................................................. 7

6.11 Microhardness ...................................................................................................................................... 7

6.12 Solderability .......................................................................................................................................... 7

6.13 Wear resistance .................................................................................................................................... 7

6.14 Ductility.................................................................................................................................................. 7

6.15 Undercoats ............................................................................................................................................ 7

6.16 Freedom from contamination .............................................................................................................. 8

6.17 Anti-tarnish treatments ........................................................................................................................ 8

7 Sampling................................................................................................................................................ 8

Annex A (normative) Requirements for undercoats....................................................................................... 9

Annex B (normative) Methods of measuring the thickness of electroplated silver and silver alloy

coatings ............................................................................................................................................... 11

Annex C (normative) Adhesion tests ............................................................................................................. 15

Annex D (normative) Determination of the presence of residual salts ...................................................... 17

Bibliography ..................................................................................................................................................... 19

© ISO 2008 – All rights reserved iii
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SIST EN ISO 4521:2008
ISO 4521:2008(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 2.

The main task of technical committees is to prepare International Standards. 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 document may be the subject of patent

rights. ISO shall not be held responsible for identifying any or all such patent rights.

ISO 4521 was prepared by Technical Committee ISO/TC 107, Metallic and other inorganic coatings,

Subcommittee SC 3, Electrodeposited coatings and related finishes.

This second edition cancels and replaces the first edition (ISO 4521:1985), and also ISO 4522-1:1985,

ISO 4522-2:1985 and ISO 4522-3:1988, which have been technically revised.
iv © ISO 2008 – All rights reserved
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SIST EN ISO 4521:2008
ISO 4521:2008(E)
Introduction

Electrodeposited silver and silver alloy coatings are often specified for their extremely good electrical

conductivity, but corrosion protection is often an additional requirement for electrical, electronic and other

applications. In many conditions of service, sulfide films may form on the coatings, increasing the contact

resistance at the silver electroplated mating surface and making them unsuitable for use in low-voltage

electronic circuits. Sulfide films are not especially detrimental to other electronic applications where higher

voltage and higher contact pressures are used, because the films are not completely insulating.

Because the appearance and serviceability of electroplated silver coatings depend on the condition of the

basis material, agreement should be reached between interested parties that the surface finish and roughness

of the basis material are satisfactory for electroplating.

Electroplated silver coatings have been used as bearing surfaces for many decades and are particularly

useful where the load-bearing surfaces are not well lubricated.

Electroplated silver coatings have largely replaced electroplated gold coatings on metallic lead frames, the

devices that support the majority of silicon chips.
© ISO 2008 – All rights reserved v
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SIST EN ISO 4521:2008
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SIST EN ISO 4521:2008
INTERNATIONAL STANDARD ISO 4521:2008(E)
Metallic and other inorganic coatings — Electrodeposited silver
and silver alloy coatings for engineering purposes —
Specification and test methods

WARNING — This International Standard may not be compliant with some countries’ health and safety

legislations and calls for the use of substances and/or procedures that may be injurious to health if

adequate safety measures are not taken. This International Standard does not address any health

hazards, safety or environmental matters and legislations associated with its use. It is the

responsibility of the user of this International Standard to establish appropriate health, safety and

environmentally acceptable practices, and take suitable actions to comply with any national and

international regulations. Compliance with this International Standard does not, in itself, confer

immunity from legal obligations.
1 Scope

This International Standard specifies requirements for electroplated silver and silver alloy coatings for

electrical, electronic and other engineering applications, including test methods. Engineering applications are

defined as those in which the coating essentially serves a non-decorative purpose.

Although this International Standard does not specify the condition, finish or surface roughness of the basis

material prior to electroplating, the appearance and serviceability of electroplated silver and silver alloy

coatings depend on the condition of the basis material. It is essential that the purchaser specifies the surface

finish and roughness of the basis material in order to conform to the product requirements.

This International Standard does not apply to coatings on screw threads or to coatings on sheet, strip or wire

in the non-fabricated form.
2 Normative references

The following referenced documents are indispensable for the application of this document. For dated

references, only the edition cited applies. For undated references, the latest edition of the referenced

document (including any amendments) applies.

ISO 1463, Metallic and oxide coatings — Measurement of coating thickness — Microscopical method

ISO 2064, Metallic and other inorganic coatings — Definitions and conventions concerning the measurement

of thickness

ISO 2080, Metallic and other inorganic coatings — Surface treatment, metallic and other inorganic coatings —

Vocabulary

ISO 2177, Metallic coatings — Measurement of coating thickness — Coulometric method by anodic

dissolution

ISO 2178, Non-magnetic coatings on magnetic substrates — Measurement of coating thickness — Magnetic

method

ISO 3497, Metallic coatings — Measurement of coating thickness — X-ray spectrometric methods

© ISO 2008 – All rights reserved 1
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SIST EN ISO 4521:2008
ISO 4521:2008(E)

ISO 3543, Metallic and non-metallic coatings — Measurement of thickness — Beta backscatter method

ISO 3868, Metallic and other non-organic coatings — Measurement of coating thicknesses — Fizeau multiple-

beam interferometry method

ISO 4516, Metallic and other inorganic coatings — Vickers and Knoop microhardness tests

ISO 4518, Metallic coatings — Measurement of coating thickness — Profilometric method

ISO 4519:1980, Electrodeposited metallic coatings and related finishes — Sampling procedures for inspection

by attributes
ISO 4538, Metallic coatings — Thioacetamide corrosion test (TAA test)

ISO 9587, Metallic and other inorganic coatings — Pretreatment of iron or steel to reduce the risk of hydrogen

embrittlement

ISO 9588, Metallic and other inorganic coatings — Post-coating treatments of iron and steel to reduce the risk

of hydrogen embrittlement

ISO 10111, Metallic and other inorganic coatings — Measurement of mass per unit area — Review of

gravimetric and chemical analysis methods

ISO 10289, Methods for corrosion testing of metallic and other inorganic coatings on metallic substrates —

Rating of test specimens and manufactured articles subjected to corrosion tests
ISO 10308, Metallic coatings — Review of porosity tests

ISO 10587, Metallic and other inorganic coatings — Test for residual embrittlement in both metallic-coated

and uncoated externally-threaded articles and rods — Inclined wedge method

ISO 12687, Metallic coatings — Porosity tests — Humid sulfur (flowers of sulfur) test

ISO 14647, Metallic coatings — Determination of porosity in gold coatings on metal substrates — Nitric acid

vapour test

ISO 15724, Metallic and other inorganic coatings — Electrochemical measurement of diffusible hydrogen in

steels — Barnacle electrode method

IEC 60068-2-20, Basic environmental testing procedures — Part 2: Tests. Test T: Soldering

3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 2064 and ISO 2080 apply.

4 Information to be supplied by the purchaser to the electroplater
4.1 Essential information

The following information shall be supplied by the purchaser to the electroplater in writing, for example, in the

purchase order or contract, or on engineering drawings:

a) the number of this International Standard (ISO 4521) and the designation (see Clause 5);

b) the significant surface indicated, for example, on drawings or by the provision of suitably marked

samples;
2 © ISO 2008 – All rights reserved
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SIST EN ISO 4521:2008
ISO 4521:2008(E)

c) the nature, condition and finish of the basis metal, if they are likely to affect the serviceability and/or the

appearance of the coating;

d) the position on the surface of unavoidable defects, such as rack marks (see 6.2);

e) the finish required, for example, bright, dull or another type, preferably accompanied by approved

samples of the finish (see 6.2);

f) the requirements for thickness, accelerated corrosion and adhesion testing (see 6.3, 6.5 and 6.9);

g) the tensile strength of parts and the requirements for heat treatment before and/or after electrodeposition

(see 6.7 and 6.8);

h) sampling methods, acceptance levels or any other inspection requirements if different from those

specified in ISO 4519:1980, Clause 7.
4.2 Additional information

If the following additional information is required, it shall be specified by the purchaser in writing, for example,

in the contract, purchase order or on the drawing with the definition.

a) the minimum silver content of the coating, details of any alloying elements, the methods of determining

the minimum silver content (see 6.6) and presence of residual salts (see 6.16);
b) any cleaning precautions to be followed;
c) any special requirements for undercoats (see 6.15 and Annex A);

d) any requirements for an anti-tarnish treatment, the type of treatment and the test method to be applied

(see 6.17);

e) the method of porosity testing to be applied, and the number and location of acceptable pores (see 6.4);

f) the electrical properties of the coating and the methods of test to be used (see 6.10);

g) the microhardness of the coating and the test method to be used (see 6.11);
h) requirements for solderability and the test method to be used (see 6.12);

i) any requirements for wear resistance and the test method to be used (see 6.13);

j) the ductility of the coating and the method of test to be used (see 6.14);

k) any requirements for freedom from contamination of the finished articles (see 6.16);

l) the density of the silver coating, if the thickness method requires a density correction (see Annex B).

5 Designation
5.1 General

The designation shall appear on engineering drawings, in the purchase order, the contract or in the detailed

product specification. The designation specifies, in the following order, the basis material, stress-relief

requirements, the type and thickness of undercoats, if present; the thickness of the silver coating, heat

treatment requirements after electroplating, and the type of conversion coating and/or supplementary

treatment.
© ISO 2008 – All rights reserved 3
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SIST EN ISO 4521:2008
ISO 4521:2008(E)
5.2 Designation specifications
The designation shall comprise the following:
a) the term, Electrodeposited coating;
b) the number of this International Standard, ISO 4521;
c) a hyphen;

d) the chemical symbol of the basis material followed by its standard designation (see 5.3);

e) a solidus (/);

f) if appropriate, the chemical symbol for an undercoat metal followed by a solidus and by a number giving

the thickness of the undercoat, in micrometres (see 6.15 and Annex A);
g) a solidus(/);

h) the chemical symbol for silver, Ag, followed by a number in parentheses giving the minimum mass

fraction of silver in the coating, expressed as a percent to one decimal place;

i) a number indicating the minimum local thickness, in micrometres, of the silver coating.

5.3 Designation of the basis material

The basis material shall be designated by its chemical symbol, or its principal constituent if it is an alloy. For

example:
a) Fe for iron or steel;
b) Zn for zinc alloys;
c) Cu for copper and copper alloys;
d) Al for aluminium and aluminium alloys.

For plateable plastics materials, the letters PL shall be used. and for non-metallic materials, the letters NM

shall be used.

It is recommended that the specific material be designated by its standard designation; for example, by its

UNS number or the local national equivalent, in parentheses, following the chemical symbol for the basis

material. For example, Fe(G43400) is the UNS designation of a high-strength steel (see References. [2] to [8]

in the Bibliography).
5.4 Designation of heat treatment requirements
The heat-treatment requirements shall be designated as follows:

a) the letters SR for stress-relief heat treatment prior to electroplating, and/or the letters ER for hydrogen-

embrittlement-relief heat treatment after electroplating;
b) in parentheses, the minimum temperature, in degrees Celsius (°C);
c) the duration of the heat treatment, in hours (h).
For example, SR(210)1 designates stress-relief heat treatment at 210 °C for 1 h.

When heat treatment prior to or after electrodeposition is specified, the requirements shall be included in the

designation as shown in the examples (see 5.5).
4 © ISO 2008 – All rights reserved
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SIST EN ISO 4521:2008
ISO 4521:2008(E)
5.5 Examples of designations

A silver coating (Ag) with a minimum thickness of 20 µm on brass (Cu) shall have the following designation:

Electrodeposited coating ISO 4521 - Cu/Ag(98,8)20

A silver alloy coating containing 98,9 % silver, Ag (98,9), with a minimum thickness of 10 µm on steel (Fe) with

a nickel undercoat (Ni) of unspecified thickness shall have the following designation:

Electrodeposited coating ISO 4521 – Fe/Ni/Ag(98,9)10

A silver alloy coating on steel containing 99,8 % silver [Ag(99,8)] with a minimum thickness of 10 µm with a

nickel undercoat (Ni) that is 5 µm thick shall have the following designation:
Electrodeposited coating ISO 4521 – Fe/Ni5/Ag(99,8)10

A silver coating with a minimum thickness of 15 µm (Ag15) deposited over a copper undercoat that is 5 µm

thick (Cu5) on steel that has an ultimate tensile strength of 1 200 MPa heat treated prior to electroplating for

stress relief at 200 °C for 3 h, SR(200)3, and after electroplating to reduce the risk of hydrogen embrittlement

at 190 °C for at least 12 h, ER(190)12, shall have the following designation:
Electrodeposited coating ISO 4521 – Fe/SR(200)3/Cu5/Ag(98,8)15/ER(190)12

The designation describes the heat treatment and electroplating steps in the order that they are performed.

The standard designation of the basis material shall be placed in parentheses immediately after the chemical

symbol for steel, Fe, in the above example. It is especially important to know the standard designation of a

metal or alloy that is difficult to prepare for electroplating and that is susceptible to hydrogen embrittlement.

6 Requirements
6.1 General

The test procedures specified in 6.2, 6.3, 6.7, 6.8, 6.9 and 6.11 for electroplated silver and silver alloy coatings

are to be performed in the absence of any anti-tarnish treatment. The tests specified in 6.6 and 6.10 shall be

carried out after the anti-tarnish treatment.
Mercury compounds shall not be used in the pretreatment of basis materials.
6.2 Appearance

Over the significant surface, the electroplated article shall be free from clearly visible defects, such as blisters,

pits, roughness, cracks or uncoated areas other than those that arise from defects in the basis material. The

electroplated article shall be free from extraneous soil and mechanical damage. On articles where a contact

mark is unavoidable, its position shall be specified by the purchaser [see 4.1 d)].

In the case of selectively electroplated articles, the amount of stain at the boundary between the areas of the

article that have been electroplated with silver and those that are not electroplated with silver shall be agreed

between the parties concerned [see 4.1 e)].

Silver and silver alloy coatings that are to be subsequently machined shall be free from excessive nodulation

and treeing at edges, and from other imperfections detrimental to subsequent fabrication.

If required, a preliminary sample with the required finish shall be supplied or approved by the purchaser [see

4.1 e)].
© ISO 2008 – All rights re
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