1、Designation: F29 97 (Reapproved 2017)Standard Specification forDumet Wire for Glass-to-Metal Seal Applications1This standard is issued under the fixed designation F29; the number immediately following the designation indicates the year of originaladoption or, in the case of revision, the year of las
2、t revision.Anumber in parentheses indicates the year of last reapproval.Asuperscriptepsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers round, copper-coated 42 %nickel-iron wire, commonly known as dumet, intended primar-ily for sealing
3、 to soft glass.1.2 The values stated in inch-pound units are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.3 This standard does not purport to address all of thesafety concern
4、s, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.1.4 This international standard was developed in accor-dance with internationally rec
5、ognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2B170 Specification
6、for Oxygen-Free Electrolytic CopperRefinery ShapesD1535 Practice for Specifying Color by the Munsell SystemD1729 Practice for Visual Appraisal of Colors and ColorDifferences of Diffusely-Illuminated Opaque MaterialsE3 Guide for Preparation of Metallographic SpecimensE29 Practice for Using Significan
7、t Digits in Test Data toDetermine Conformance with SpecificationsE53 Test Method for Determination of Copper in UnalloyedCopper by GravimetryE228 Test Method for Linear Thermal Expansion of SolidMaterials With a Push-Rod DilatometerF14 Practice for Making and Testing Reference Glass-MetalBead-Seal3.
8、 Ordering Information3.1 The wire is usually supplied with a surface coatingconsisting of a mixture of copper oxides and fused sodiumtetraborate (borax) which retards oxidation of the wire duringsealing in glass and further aids wetting of the wire by theglass. The composite wire may also be purchas
9、ed as bare wirefor specific applications.3.2 The size of the wire, if applicable, the borate color rangedesignated as light, medium (regular), or dark, shall bespecified on each purchase order.3.3 Package sizes shall be agreed upon between the pur-chaser and the seller.4. Chemical Composition4.1 The
10、 copper used in the manufacture of dumet shall be99.90 % minimum copper. Silver shall be included with thecopper. The material shall be free of reducible oxides.4.2 The chemical composition of the nickel-iron core shallbe as shown in Table 1.5. Oxide Coating5.1 The primary standards for the entire r
11、ange of colors aredivided into three groups covering light, medium (regular), anddark as shown, with their respective limits, in Fig. 1 and Table2 (Note 1). The color range of the specimens shall bedetermined in accordance with 9.2.NOTE 1Color chip 2.5R 3.90/8.0 may be included in the dark rangemere
12、ly to extend the color series for assisting the viewer in making abetter decision regarding the cut-off point between medium (regular) anddark dumet.6. Thermal Expansion6.1 The nominal values for the average coefficient of linearthermal expansion shall be as follows when determined inaccordance with
13、 9.1:6.1.1 Core63 to 72 107in./in.deg C (mm/mmdegC) over the temperature range of 30 to 400C.6.1.2 Copper177 6 3.5107in./in.C (mm/mmdegC) over the temperature range of 30 to 300C.1This specification is under the jurisdiction of ASTM-Committee F01 onElectronics and is the direct responsibility of Sub
14、committee F01.03 on MetallicMaterials.Current edition approved June 1, 2017. Published June 2017. Originallyapproved in 1963. Last previous edition approved in 2012 as F29 97(2012). DOI:10.1520/F0029-97R17.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer
15、Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed
16、in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.17. Dimensional Tolerance
17、s7.1 The specified diameters shall conform to the tolerancesgiven in Table 3.8. Workmanship and Finish8.1 Internal ConditionThe internal structure of the com-posite material, including the bond area, shall be sound andfree from pipes, porosity, or discontinuities which mightprevent the making of a s
18、atisfactory seal.8.2 Surface Condition:8.2.1 There shall be no areas of exposed core evident on thesurface of the wire.8.2.2 The wire shall contain no longitudinal scratches, folds,or lines of a depth greater than the width.8.2.3 There shall be no oil, grease, or other surface contami-nants on the w
19、ire.8.2.4 The wire shall be looped or coiled over a mandrel fivetimes the diameter of the wire. At least 75 % of the dumet areashall be free from defects consisting of damaged borate,exposing the copper, when observed at 10 magnification.8.2.5 The nickel-iron core shall be uniformly covered with18 %
20、 to 28 % copper (by weight) and the ratio of maximum tominimum sheath thickness shall not exceed 2.5 to 1 on anycross section.NOTE 2The sheath is defined as that area exclusive of the core.8.3 StorageFinished material should be stored in a con-tainer or room with a maximum relative humidity of 50 %.
21、9. Test Methods9.1 Thermal ExpansionDetermine the thermal expansioncharacteristics in accordance with Test Method E228, exceptthat the specimen shall be preheated as follows:9.1.1 Heat the core rod specimen in a hydrogen atmospherefor1hat900C; then cool it from 900 to 200C at a rate notexceeding 5C/
22、min.9.1.2 Determine the thermal expansion charateristics inaccordance with Test Method E228.9.2 Color of Coating Mount the color chips3on a neutralbackground (middle gray to white) as shown in Fig. 1. Windthe specimen to be tested or compared on a flat surface similarto that shown in Fig. 1. Each tu
23、rn of the wire should lie paralleland as close as possible to the preceding turn without overlap-ping. View the specimen in natural or artificial daylight inaccordance with either or both Method D1535,(Note 3) or TestMethod D1729, Fig. 2.NOTE 3Coated wire carries a mixture of copper oxides and fused
24、sodium tetraborate on the surface of the dumet, which dissolves, wholly orin part, into the glass during the sealing operation. The sealing techniqueis influenced by the amount of coating, and color has been established asa means of estimating the thickness of this mixture. The color varies froma da
25、rk red-purple to a light yellow-red as the thickness decreases. Themethod, described in Test Method D1535, is based on the color-perceptionattributes of hue, lightness, and saturation and is used as the means forspecifying color. This method employs the Munsell color-notation systemin which visual s
26、cales are assigned to each of the color-perceptionattributes. In this system, the attributes are called hue, H, value, V, andchroma, C, written in the form H V/C. By using a combination of numbersand letters, apparent color may be exactly specified. The dimensions of thesurface-color-perception soli
27、d are illustrated in Fig. 2.9.3 DiameterThe diameter of the wire in coils shall bemeasured at each end. When wire is spooled, approximately 6ft (1.8 m) shall be unreeled and the diameter of the wiremeasured between the second and sixth foot from the end. Theaverage of the measurements obtained on an
28、y coil or spoolshall be within the limits specified in Section 7.9.4 Reducible Oxides Copper shall be tested for reducibleoxides in accordance with the methods described in Specifica-tion B170.9.5 Copper Analysis Copper shall be analyzed by wetchemical methods in accordance with Methods E53.9.6 Meta
29、llographic TestThe internal structure of the wireshall be checked by standard metallographic methods asdescribed in Method E3.10. Rejection10.1 Any spool or coil not conforming to the requirementsof this specification may be rejected. If 15 % or more of thespools in any shipment do not conform to th
30、e specifiedrequirements, the entire shipment may be rejected.11. Packaging and Marking11.1 Unless otherwise specified, wire supplied on spools orcoils shall be continuous with no joints of any type.3The sole source of supply of the color standards known to the committee at thistime is the Munsell Co
31、lor Company, Inc., 2441 N. Calvert St., Baltimore, MD21218. If you are aware of alternative suppliers, please provide this information toASTM Headquarters.Your comments will receive careful consideration at a meetingof the responsible technical committee11, which you may atttend.TABLE 1 Chemical Req
32、uirements: Core MaterialElement Composition, %Nickel 41 to 43Manganese 0.75 to 1.25Silicon, max 0.30Carbon, max 0.10Sulfur, max 0.02Phosphorus, max 0.02Iron (by difference) remainderTABLE 2 Color Ranges and LimitsDark RangeMedium (Regular)RangeLight RangeColors darker than chip 3.5R3.94/8.03.5R 3.94
33、/8.0 to 6.5R4.06/8.0, incl7.5R 4.22/8.0 to 0.5YR4.56/8.0 inclTABLE 3 Dimensional TolerancesDiameter, in. (mm) Tolerance, in.(mm)0.007 to 0.013 (0.18 to 0.33) 0.0003 (0.008)Over 0.013 to 0.018 (0.33 to 0.46) 0.0004 (0.010)Over 0.018 (0.46) 0.0005 (0.013)F29 97 (2017)211.2 The wire shall be spooled in
34、 such a manner that it canbe unwound under reasonable tension without binding orotherwise becoming distorted.11.3 Each spool or coil shall be marked as to wire size,color, date, net weight, and lot number.11.4 Containers shall be free from any dirt, dust, oil, orother agents that may contaminate the
35、 material.11.5 Each individual spool shall be packaged in a suitableplastic bag, such as polyethylene.12. Keywords12.1 gloss-to-metal sealing; iron-nickel/copper compositewire; vacuum electronicsNOTE 1Wire winding shall be in the same plane as shown and the specimen in the same plane as the color ch
36、ips. The specimen shall be viewed alongdirection AB at an inclined angle as illustrated.FIG. 1 Arrangement of Color Chips for Specimen ComparisonNOTE 1The circular band represents the hues in their proper sequence. The upright center axis is the scale of value. The paths pointing outward fromthe cen
37、ter show the steps of chroma, increasing in strength as indicated by the numerals.FIG. 2 Hue, Value, and Chroma in Their Relationship to One AnotherF29 97 (2017)3SUPPLEMENTARY REQUIREMENTSSUPPLEMENTARY NOTESNOTE S1For the purpose of calculating weights, cross sections, etc.,the density of the copper
38、 shall be taken as 8.89 g/cm3at 20C and thenickel-iron core as 8.12 g/cm3at 20C.NOTE S2Dumet is not generally used in sizes above 0.040 in. (1.0mm).NOTE S3Expansion values have been listed for information purposesonly.NOTE S4Several references and calculated values indicate the radialexpansion of du
39、met to be 90 107in. in.deg C (mm/mmdeg C) overthe temperature range of 25 to 400C.NOTE S5This material is intended for average applications. It isrealized that for special cases a more precise definition of requirementsmay be necessary, but these are subject to individual agreement betweenthe manufa
40、cturer and the purchaser.NOTE S6Some users may require a metal-to-glass seal test similar tothat described in Practice F14.NOTE S7Observed or calculated values obtained from analyses,measurements, or tests shall be rounded off in accordance with therounding-off method given in Practice E29. These va
41、lues shall be roundedoff to the nearest unit in the last right-hand place of figures used inexpressing the specified limit.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expr
42、essly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revise
43、d, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may
44、attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United State
45、s. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 97 (2017)4
