（2）美国钨铜标准，ASTMB 702-93 (2019) Copper-Tungsten Electrical Contact Material.pdf

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: B702 − 93 (Reapproved 2019) Standard Speciﬁcation for Copper-Tungsten Electrical Contact Material 1 This standard is issued under the ﬁxed designation B702; 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 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 speciﬁed 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 copper tungsten by powder metallurgical procedures. 1.2 This speciﬁcation covers compositions within the cop- per tungsten system normally speciﬁed by users of contacts. 1.3 The values stated in inch-pound units are to be regarded as standard. No other units of measurement are included in this standard. 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 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. 1.5 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. 4. Ordering Information 4.1 Orders for this material under this speciﬁcation shall include the following information: 4.1.1 Dimensions (see Section 8), 4.1.2 Chemical composition (see reference tables in Related Material as possible guideline), 4.1.3 Physical properties (see Section 6 and reference tables as guideline), 4.1.4 Certiﬁcation (see Section 11), and 4.1.5 Other features as agreed upon between the vendor and the user. 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 Bearings (Withdrawn 2009) 3 5. Chemical Requirements 5.1 The material shall conform to composition limits as agreed upon between the manufacturer and the user. 3. Signiﬁcance and Use 3.1 Proprietary methods for manufacture of these materials vary signiﬁcantly among suppliers and these methods inﬂuence 5.2 The chemical analysis shall be made in accordance with the methods prescribed in the newest edition of Annual Book of ASTM Standards, or by any other approved method agreed upon between the manufacturer and the purchaser. 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 Nov. 1, 2019. Published November 2019. Originally approved in 1982. Last previous edition approved in 2015 as B702 – 93 (2015). DOI: 10.1520/B0702-93R19. 6. Other Properties 6.1 The manufacturer and the purchaser shall agree on qualiﬁcation tests for determination of physical properties. 2 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 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. 6.2 The tests shall be performed on production parts, wherever practical or applicable. (Small size contacts do not lend themselves to accurate conductivity measurement.) Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States 1 B702 − 93 (2019) 9.2.1 These speciﬁcation limits do not preclude the possible presence of other unnamed elements, impurities or additives. Analysis shall be regularly made only for the minor elements listed in the table. However, if a user knows of elements that might be detrimental to their application or has other reasons for requiring analysis for speciﬁc elements, then agreement between manufacturer and purchaser for both limits and methods of analysis should be required for elements not speciﬁed. 6.3 The tests shall be determined after consideration of the function of the part. 6.4 The typical properties of ﬁve most common types of copper-tungsten contacts are given in Appendix X1. 7. Dimensions and Permissible Variations 7.1 Permissible variations in dimensions shall be within the limits speciﬁed on drawings describing the contacts and accompanying the order, or shall be within the limits speciﬁed in the purchase order. 9.3 Physical Tests—The manufacturer and the purchaser shall agree on a representative number of specimens for physical tests including microstructure. 8. Workmanship, Finish, and Appearance 8.1 The parts shall be free of defects in material or processing, which would seriously affect their performance. 10. Rejection and Rehearing 10.1 Unless otherwise speciﬁed, rejections based on tests made in accordance with the speciﬁcation shall be reported to the manufacturer within 30 days of the receipt of shipment. 9. Sampling and Inspection 9.1 Lot—Unless otherwise speciﬁed, a lot shall consist of parts of the same form, and dimensions, made of powders of the same particle size range and composition, processed under the same conditions, and submitted for inspection at one time. 11. Certiﬁcation 11.1 A certiﬁcation, when requested by the user, based on the manufacturer’s quality control, that the material conforms to the requirements of this speciﬁcation shall be furnished upon request of the purchaser, provided the request is made at the time of cost quotation and at the time of order placement. 9.2 Chemical Analysis—At least one sample for chemical analysis shall be taken from each lot. A representative sample of chips may be obtained by milling, drilling, or crushing at least two pieces with dry tools, without lubrication. In order to obtain oil-free chips, the parts selected for test shall have the oil extracted in accordance with Test Method B328, if neces- sary. 12. Keywords 12.1 contacts; copper; copper–tungsten; powder metallurgy; tungsten; tungsten–copper APPENDIX (Nonmandatory Information) X1. TYPICAL PROPERTY VALUES X1.1 Scope application should be mutually decided between the purchaser and the supplier using their mutual experience and application engineering knowledge. X1.1.1 The following information provides guidelines for users and manufacturers of copper-tungsten contact material. Typical ranges of chemistry and properties are given for the range of compositions available. Some manufacturers offer speciﬁc compositions other than those listed. Properties are inﬂuenced by the particle size, shape, and distribution of the tungsten as well as by the presence of additives or other manufacturing process variables. The best choice for a given X1.1.2 With the knowledge that several types of material are available, care should be taken to ensure that production lots are the same in all respects as samples and that if a vendor change is made, noticeable property or performance variables are possible. See Table X1.1. 2 B702 − 93 (2019) TABLE X1.1 Chemical Requirements Copper, % Tungsten, % Additives (Individual or total), max,% Hardness, Rockwell B 3 Density, Mg/m at 96 % theoretical C Electrical conductivity, % IACS Electrical conductivity, D % IACS Note—Hardness and density values cover both types. Tensile Strength, ksi MPa Modulus of Rupture, ksi MPa Coefficient of Expansion, in./in.· °F m/m·K A Class A Class B Class C Class D Class E 48–52 balance 1.00 38–42 balance 1.00 23–27 balance 1.00 18–22 balance 1.00 Class A 69–83 11.7 56–64 38–56 Class B 77–90 12.7 49–57 34–49 28–32 balance 1.00 Physical Properties Class C 85–98 13.7 44–52 29–43 Class D 89–102 14.3 41–48 27–41 Class E 94–106 15.0 38–45 25–37 Class B 55–65 379–448 110–120 758–827 −6 6.6 × 10 −6 11.9 × 10 Physical Properties Class C 75–85 516–585 130–140 896–965 −6 5.7 × 10 −6 10.3 × 10 Class D 85–95 585–654 140–150 965–1034 −6 5.3 × 10 −6 9.5 × 10 Class E 90–100 620–689 150–160 1034–1103 −6 4.9 × 10 −6 8.8 × 10 Class A 50–60 344–413 75–85 517–586 −6 7.2 × 10 −6 13 × 10 B E Analysis is regularly made for the elements for which speciﬁc limits are listed. If, however, the presence of “other” elements is suspected or indicated in the course of routine analysis, further analysis shall be made to determine that the total of these “other” elements and the listed impurities are not in excess of the total impurities limit. B These data do not constitute a part of the speciﬁcations. They indicate to the purchaser the properties that may be expected from a given particle size of powder. The values will vary to some degree with the size of part, conﬁguration of part, composition, and microstructure. Certain speciﬁc applications may require modiﬁcation of these basic materials. In such case, the properties required are determined by agreement between the purchaser and the supplier. C Typical values for inﬁltrated type. D Typical values for liquid phase sintered type. E Items that are normally useful for engineering calculations in contact design but are not speciﬁed. 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