ASTM B662-94(2006)
(Specification)Standard Specification for Silver-Molybdenum Electrical Contact Material
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 normally specified by users of contacts.
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 and health practices, and determine the applicability of regulatory limitations prior to use.
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: B662 – 94 (Reapproved 2006)
Standard Specification for
Silver-Molybdenum Electrical Contact Material
This standard is issued under the fixed designation B662; 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 4. Chemical Composition
1.1 This specification covers electrical contact components 4.1 The material shall conform to composition limits as
made from silver-molybdenum by powder metallurgical pro- agreed upon between the manufacturer and the purchaser.
cedures. 4.2 The chemical analysis shall be made in accordance with
1.2 Thisspecificationcoverscompositionswithinthesilver- the methods prescribed in the newest edition of Volume 01.02
molybdenum system normally specified by users of contacts. of the Annual Book of ASTM Standards or by any other
1.3 This standard does not purport to address all of the approved method agreed upon between the manufacturer and
safety concerns, if any, associated with its use. It is the the purchaser.
responsibility of the user of this standard to become familiar
5. Physical Properties
with all hazards including those identified in the appropriate
5.1 The manufacturer and the purchaser shall agree on
Material Safety Data Sheet (MSDS) for this product/material
as provided by the manufacturer, to establish appropriate qualification tests for determination of physical properties.
5.2 The tests shall be performed on production parts,
safety and health practices, and determine the applicability of
regulatory limitations prior to use. wherever practical or applicable. (Small size contacts do not
lend themselves to accurate conductivity measurement.)
2. Referenced Documents
5.3 The tests shall be determined after consideration of the
2.1 ASTM Standards: function of the part.
B328 Test Method for Density, Oil Content, and Intercon- 5.4 The typical properties of two most common types of
nected Porosity of Sintered Metal Structural Parts and silver-molybdenum contacts are given in the appendix.
Oil-Impregnated Bearings
6. Finishing of Contacts
3. Ordering Information
6.1 The material shall be finished by such operations as
3.1 Orders for this material under this specification shall necessary to meet requirements agreed upon between the
include the following information: manufacturer and the purchaser of the contacts (braze alloy
3.1.1 Dimensions (see Section 10), backing, tumbling to polish surfaces, special surface finish,
3.1.2 Chemical composition (see tables in the appendix as a silver-rich surface layer, cleaning, etc.).
guideline),
7. Dimensions, Mass and Permissible Variations
3.1.3 Physical properties (see Section 5 and the appendix as
a guideline), 7.1 Permissible variations in dimensions shall be within the
limits specified on drawings describing the contacts and
3.1.4 Certification (see Section 13), and
3.1.5 Other features as agreed upon between the manufac- accompanying the order; or shall be within the limits specified
in the purchase order.
turer and purchaser.
8. Workmanship, Finish, and Appearance
This specification is under the jurisdiction of ASTM Committee B02 on
8.1 The parts shall be free of defects in material or process-
Nonferrous Metals and Alloys and is the direct responsibility of Subcommittee
B02.05 on Precious Metals and Electrical Contact Materials. ing that would seriously affect their performance.
Current edition approved June 1, 2006. Published June 2006. Originally
approved in 1979. Last previous edition approved in 2000 as B662 – 94 (2000).
9. Significance and Use
DOI: 10.1520/B0662-94R06.
9.1 Proprietary methods for the manufacture of these mate-
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM rials vary significantly among suppliers, and these methods
Standards volume information, refer to the standard’s Document Summary page on
influence such properties as arc erosion, contact resistance, and
the ASTM website.
the tendency to weld in service. Since the performance of
Withdrawn. The last approved version of this historical standard is referenced
contacts in a device depends on numerous factors outside the
on www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
B662 – 94 (2006)
contact itself (opening speed, closing speed, contact pressure, elements that might be detrimental to their application or has
contact bounce, environmental variations, assembly technique other reasons for requiring analysis for specific elements, then
and variations, etc.), this specification cannot ensure perfor- agreement between manufacturer and purchaser for both limits
mance control in the application.As part of the qualification on and methods of analysis should be required for elements not
initial samples, it is recommended that the user functionally specified.
and electrically test the materials for all devices applicable to 10.3 Physical Tests—The manufacturer and the purchaser
the material’s use. This specification will provide a means for shall agree on a representative number of specimens for
the contact manufacturer and contact user to reach agreement physical tests including microstructure.
on the details of the material to be supplied for a specific use,
11. Inspection
and reasonable assurance that future lots will be similar in
properties and microstructure to the initial test or sample 11.1 Unlessotherwisespecified,inspectionofpartssupplied
on contract shall be made by the purchaser.
contacts supplied.
10. Sampling 12. Rejection
10.1 Lot—Unless otherwise specified, a lot shall consist of
12.1 Unless otherwise specified, rejections based on tests
partsofthesameformanddimensions,madeofpowdersofthe made in accordance with the specification
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