Active Standard ASTM B631 | Developed by Subcommittee: B02.05
Book of Standards Volume: 02.04
Historical (view previous versions of standard)
This specification covers electrical contact components made from silver-tungsten by powder-metallurgical procedures. The material shall conform to composition limits specified. The material shall be finished by braze alloy backing, tumbling to polish surfaces, special surface finish, silver-rich surface layer, cleaning, etc. Chemical analysis and physical test shall be made to conform to the specified requirements.
This abstract is a brief summary of the referenced standard. It is informational only and not an official part of the standard; the full text of the standard itself must be referred to for its use and application. ASTM does not give any warranty express or implied or make any representation that the contents of this abstract are accurate, complete or up to date.
Significance and Use
Proprietary methods for manufacture of these materials vary significantly among suppliers, and these methods influence such properties as arc erosion, contact resistance, and 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 variations, etc.) this specification cannot ensure performance control in the application. As part of the qualification on initial samples it is recommended that the user functionally electrically test the materials for all devices applicable to the material's use. This specification will provide a means for the contact manufacturer and contact user to reach agreement on the details of material to be supplied for a specific use and reasonable assurance that future lots will be similar in properties and microstructure to the initial test or sample contacts supplied.
1.1 This specification covers electrical contact components made from silver-tungsten by powder-metallurgical procedures.
1.2 This specification covers compositions within the silver-tungsten system normally specified by users of contacts.
1.3 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 Data Safety 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.
2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
B328 Test Method for Density, Oil Content, and Interconnected Porosity of Sintered Metal Structural Parts and Oil-Impregnated Bearings
ICS Number Code 77.120.99 (Other non-ferrous metals and their alloys)