ASTM B780-98(2004)
(Specification)Standard Specification for 75% Silver, 24.5% Copper, 0.5% Nickel Electrical Contact Alloy
Standard Specification for 75% Silver, 24.5% Copper, 0.5% Nickel Electrical Contact Alloy
ABSTRACT
This specification covers electrical contact alloys with the nominal composition of 75% silver, 24.5% copper, and 0.5% nickel in the form of rods, wires, strips, and sheets. Raw materials shall be of such quality and purity that the products, which shall be finished by such operations as cold working, heat treatment, annealing, turning, grinding, or pickling, shall adhere to the chemical composition and mechanical property requirements prescribed here. Besides analysis for the elements silver, copper, and nickel, further analysis is to be made for suspected or indicated impurities, such as zinc, iron, cadmium, and lead, to make sure that their total does not exceed specified limits. Mechanical tests, which are to be conducted at room temperature, shall evaluate the materials' tensile strength, elongation, Rockwell hardness, and area and thickness reduction.
SCOPE
1.1 This specification covers an electrical contact material with the nominal composition of 75 % silver, 24.5 % copper, and 0.5 % nickel in the form of rod, wire, strip, and sheet.
This standard does not purport to address all 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 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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: B780 – 98 (Reapproved 2004)
Standard Specification for
75 % Silver, 24.5 % Copper, 0.5 % Nickel Electrical Contact
Alloy
This standard is issued under the fixed designation B780; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
TABLE 1 Chemical Composition
1. Scope
1.1 This specification covers an electrical contact material NOTE 1—Analysisisregularlymadefortheelementsforwhichspecific
limitsarelisted.Ifhowever,thepresenceof“other”elementsissuspected
with the nominal composition of 75% silver, 24.5% copper,
or indicated in the course of routine analysis, further analysis shall be
and 0.5% nickel in the form of rod, wire, strip, and sheet.
made to determine that the total of these “other” elements and the listed
1.2 This standard does not purport to address all the safety
impurities is not in excess of the total impurities limit.
concerns, if any, associated with its use. It is the responsibility
NOTE 2—Refer to 5.2.
of the user of this standard to become familiar with all hazards
including those identified in the appropriate Material Safety
Element Weight,%
Data Sheet for this product/material as provided by the
Silver 74.0–76.0
manufacturer, to establish appropriate safety and health prac-
Copper (23.5 min) report by difference
tices, and determine the applicability of regulatory limitations Nickel 0.35–0.65
prior to use.
Impurities
Zinc 0.06 max
2. Referenced Documents
Iron 0.05 max
Cadmium 0.05 max
2.1 ASTM Standards:
Lead 0.03 max
B476 Specification for General Requirements for Wrought
Total of all impurities 0.15 max
Precious Metal Electrical Contact Materials
3. Ordering Information
5.2 These specification limits do not preclude the possible
3.1 Refer to Specification B476.
presence of other unnamed elements, impurities, or additives.
Analysis shall be regularly made only for the minor elements
4. Materials and Manufacture
listed in the table. However, if a user knows of elements that
4.1 Raw materials shall be of such quality and purity that
might be detrimental to their application or has other reasons
thefinishedproductwillhavethepropertiesandcharacteristics
for requiring analysis for specific elements, then agreement
prescribed in this specification.
between manufacturer and purchaser for both limits and
4.2 The material shall be finished by such operations (cold
methods of analysis should be required for elements not
working, heat-treating, annealing, turning, grinding, or pick-
specified.
ling) as are required to produce the prescribed properties.
6. Mechanical Properties
5. Chemical Composition
6.1 Thematerialshallconformtotheapplicablemechanical
5.1 Materialproducedunderthisspecificationshallconform
properties prescribed in Table 2 or Table 3.
to the chemical composition limits prescribed in Table 1.
6.2 Alltestspecimensshallbethefullthicknessordiameter
as the size supplied when practical. The test procedures shall
follow the ASTM specifications referred to in Specification
This specification is under the jurisdiction of ASTM Committee B02 on
B476.
Nonferrous Metals and Alloys and is the direct responsibility of Subcommittee
6.3 Alltestsaretobeconductedatroomtemperature,about
B02.05 on Precious Metals and Electrical Contact Materials
...
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