ASTM B662/B662M-20

Standard Specification for Silver-Molybdenum Electrical Contact Material

ABSTRACT
This specification covers electrical contact components made from silver-molybdenum by powder metallurgical procedures. Chemical analysis of the samples shall be done to determine their chemical composition. The material shall be finished by different methods like braze alloy backing, tumbling to polish surfaces, special surface finish, and cleaning.
SCOPE
1.1 This specification covers electrical contact components made from silver-molybdenum by powder metallurgical procedures.  
1.2 This specification covers compositions within the silver-molybdenum system for electrical contact applications.  
1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.  
1.4 This 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 standard to become familiar with all hazards including those identified in the appropriate Material Safety Data Sheet (MSDS) for this product/material as provided by the manufacturer, to establish appropriate safety, health, and environmental practices, and determine the applicability of regulatory limitations prior to use.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-Mar-2020
• ICS: 77.120.99 - Other non-ferrous metals and their alloys
• Technical Committee: B02 - Nonferrous Metals and Alloys
• Drafting Committee: B02.05 - Precious Metals and Electrical Contact Materials and Test Methods

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: B662/B662M −20
Standard Specification for
1
Silver-Molybdenum Electrical Contact Material
This standard is issued under the fixed designation B662/B662M; the number immediately following the designation indicates the year
of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval.
A superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope* B542 Terminology Relating to Electrical Contacts and Their
Use
1.1 This specification covers electrical contact components
made from silver-molybdenum by powder metallurgical pro-
3. Terminology
cedures.
3.1 For terms related to electrical contacts and their use,
1.2 Thisspecificationcoverscompositionswithinthesilver-
refer to Terminology B542.
molybdenum system for electrical contact applications.
4. Ordering Information
1.3 The values stated in either SI units or inch-pound units
are to be regarded separately as standard. The values stated in
4.1 Include the following information when placing orders
each system are not necessarily exact equivalents; therefore, to
for product under this specification:
ensure conformance with the standard, each system shall be
4.1.1 Dimensions and tolerances,
used independently of the other, and values from the two
4.1.2 Alloy composition,
systems shall not be combined.
4.1.3 Physical properties,
4.1.4 Certification, and
1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the 4.1.5 Otherrequirementsasagreeduponbetweenthemanu-
facturer and purchaser.
responsibility of the user of this standard to become familiar
with all hazards including those identified in the appropriate
5. Materials and Manufacture
Material Safety Data Sheet (MSDS) for this product/material
as provided by the manufacturer, to establish appropriate
5.1 The materials shall be of such purity and soundness so
safety, health, and environmental practices, and determine the
as to be suitable for the intended application.
applicability of regulatory limitations prior to use.
NOTE 1—Proprietary methods for the manufacture of these materials
1.5 This international standard was developed in accor-
vary significantly among suppliers, and these methods influence such
dance with internationally recognized principles on standard-
properties as arc erosion, contact resistance, and the tendency to weld in
ization established in the Decision on Principles for the
service. Since the performance of contacts in a device depends on
numerous factors outside the contact itself (opening speed, closing speed,
Development of International Standards, Guides and Recom-
contact pressure, contact bounce, environmental variations, assembly
mendations issued by the World Trade Organization Technical
technique and variations, etc.), it is recommended that, as part of the
Barriers to Trade (TBT) Committee.
qualification on initial samples, the user should functionally and electri-
callytestthematerialsforalldevicesapplicabletothematerial’suse.This
2. Referenced Documents
specification provides a means for the contact manufacturer and contact
2
user to reach agreement on the details of the material to be supplied for a
2.1 ASTM Standards:
specific use, and reasonable assurance that future lots will be similar in
B328 Test Method for Density, Oil Content, and Intercon-
properties and microstructure to the initial test or sample contacts
nected Porosity of Sintered Metal Structural Parts and
supplied.
3
Oil-Impregnated Bearings (Withdrawn 2009)
6. Chemical Composition
1
6.1 Thematerialshallconformtochemicalcompositionand
This specification is under the jurisdiction of ASTM Committee B02 on
Nonferrous Metals and Alloys and is the direct responsibility of Subcommittee
impurity limits as agreed upon between the manufacturer and
B02.05 on Precious Metals and Electrical Contact Materials.
the purchaser.
Current edition approved April 1, 2020. Published April 2020. Originally
approved in 1979. Last previous edition approved in 2012 as B662 – 94 (2012).
6.2 Thecompositionalrequirementsareaffectedbyprocess-
DOI: 10.1520/B0662_B0662M-20.
ing. Table 1 covers infiltrated silver-molybdenum contact
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
alloys, and Table 2 covers pressed, sintered, and re-pressed
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on silver-molybdenum contact alloys.
the ASTM website.
3
6.3 The chemical analysis of the alloy shall be made in
The last approved version of this
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: B662 − 94 (Reapproved 2012) B662/B662M − 20
Standard Specification for
1
Silver-Molybdenum Electrical Contact Material
This standard is issued under the fixed designation B662;B662/B662M; the number immediately following the designation indicates the
year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last
reapproval. A superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope Scope*
1.1 This specification covers electrical contact components made from silver-molybdenum by powder metallurgical procedures.
1.2 This specification covers compositions within the silver-molybdenum system normally specified by users of contacts.for
electrical contact applications.
1.3 The values stated in either SI units or inch-pound units are to be regarded as standard. No other units of measurement are
included in this standard.separately as standard. The values stated in each system are not necessarily exact equivalents; therefore,
to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems
shall not be combined.
1.4 This 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 standard to become familiar with all hazards including those identified in the appropriate Material Safety Data
Sheet (MSDS) for this product/material as provided by the manufacturer, to establish appropriate safety safety, health, and
healthenvironmental practices, and determine the applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2
2.1 ASTM Standards:
B328 Test Method for Density, Oil Content, and Interconnected Porosity of Sintered Metal Structural Parts and Oil-Impregnated
3
Bearings (Withdrawn 2009)
B542 Terminology Relating to Electrical Contacts and Their Use
3. Terminology
3.1 For terms related to electrical contacts and their use, refer to Terminology B542.
4. Ordering Information
4.1 Orders for this material under this specification shall include the following information:Include the following information
when placing orders for product under this specification:
4.1.1 Dimensions (see Section and tolerances,10),
4.1.2 Chemical composition (see tables in the appendix as a guideline),Alloy composition,
4.1.3 Physical properties (see Section properties,5 and the appendix as a guideline),
4.1.4 Certification (see Section Certification, 13), and
4.1.5 Other featuresrequirements as agreed upon between the manufacturer and purchaser.
5. Materials and Manufacture
5.1 The materials shall be of such purity and soundness so as to be suitable for the intended application.
NOTE 1—Proprietary methods for the manufacture of these materials vary significantly among suppliers, and these methods influence such properties
1
This specification is under the jurisdiction of ASTM Committee B02 on Nonferrous Metals and Alloys and is the direct responsibility of Subcommittee B02.05 on
Precious Metals and Electrical Contact Materials.
Current edition approved May 1, 2012April 1, 2020. Published May 2012April 2020. Originally approved in 1979. Last previous edition approved in 20062012 as
B662 – 94 (2006).(2012). DOI: 10.1520/B0662-94R12.10.1520/B0662_B0662M-20.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
3
The last approved version of this historical standard is referenced on www.astm.org.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

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B662/B662M − 20
as arc erosion, contact resistance, and the tendency to weld in service. Since the performance of contacts in a device depends on numerous factors outside
the contact itself (opening speed, closing speed, contact pressure, contact bounce, environmental variations, assembly technique and
...