Significance and Use
9.1 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.
Abstract
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.
Scope
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 Data Safety Sheet (SDS) 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.
1.4 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.
