ASTM F29-97(2022)

Standard Specification for Dumet Wire for Glass-to-Metal Seal Applications

ABSTRACT
This specification covers the properties and requirements for round, copper-coated 42 % nickel-iron wire, commonly known as dumet, intended primarily for sealing to soft glass. The wires shall conform to requirements stated for chemical composition, oxide coatings, dimension, internal and surface workmanship, and storage characteristics. Materials shall also undergo tests for thermal expansion, color of coating, diameter, reducible oxides, copper analysis, and metallography.
SCOPE
1.1 This specification covers round, copper-coated 42 % nickel-iron wire, commonly known as dumet, intended primarily for sealing to soft glass.  
1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.  
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 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.

General Information

• Status: Published
• Publication Date: 30-Apr-2022
• ICS: 31.240 - Mechanical structures for electronic equipment
• Technical Committee: F01 - Electronics
• Drafting Committee: F01.03 - Metallic Materials, Wire Bonding, and Flip Chip

Relations

• Refers: ASTM F14-80(2019) - Standard Practice for Making and Testing Reference Glass-Metal Bead-Seal
• Effective Date: 01-Nov-2019
• Refers: ASTM E228-11(2016) - Standard Test Method for Linear Thermal Expansion of Solid Materials With a Push-Rod Dilatometer
• Effective Date: 01-Sep-2016
• Refers: ASTM B170-99(2015) - Standard Specification for Oxygen-Free Electrolytic Copper—Refinery Shapes
• Effective Date: 15-Oct-2015
• Refers: ASTM F14-80(2015) - Standard Practice for Making and Testing Reference Glass-Metal Bead-Seal
• Effective Date: 01-May-2015
• Refers: ASTM D1535-14 - Standard Practice for Specifying Color by the Munsell System
• Effective Date: 01-Nov-2014
• Refers: ASTM D1535-13 - Standard Practice for Specifying Color by the Munsell System
• Effective Date: 01-Jan-2013
• Refers: ASTM D1535-12a - Standard Practice for Specifying Color by the Munsell System
• Effective Date: 15-Jul-2012
• Refers: ASTM D1535-12 - Standard Practice for Specifying Color by the Munsell System
• Effective Date: 01-Feb-2012
• Refers: ASTM F14-80(2010) - Standard Practice for Making and Testing Reference Glass-Metal Bead-Seal
• Effective Date: 01-Apr-2010
• Refers: ASTM B170-99(2010) - Standard Specification for Oxygen-Free Electrolytic Copper—Refinery Shapes
• Effective Date: 01-Apr-2010
• Refers: ASTM D1729-96(2009) - Standard Practice for Visual Appraisal of Colors and Color Differences of Diffusely-Illuminated Opaque Materials
• Effective Date: 01-Dec-2009
• Refers: ASTM E29-08 - Standard Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
• Effective Date: 01-Oct-2008
• Refers: ASTM D1535-08 - Standard Practice for Specifying Color by the Munsell System
• Effective Date: 01-Jan-2008
• Refers: ASTM D1535-08e1 - Standard Practice for Specifying Color by the Munsell System
• Effective Date: 01-Jan-2008
• Refers: ASTM E53-07 - Standard Test Method for Determination of Copper in Unalloyed Copper by Gravimetry
• Effective Date: 15-Nov-2007

Standards Content (Sample)

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:F29 −97 (Reapproved 2022)
Standard Specification for
Dumet Wire for Glass-to-Metal Seal Applications
ThisstandardisissuedunderthefixeddesignationF29;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope E228Test Method for Linear Thermal Expansion of Solid
Materials With a Push-Rod Dilatometer
1.1 This specification covers round, copper-coated 42%
F14Practice for Making andTesting Reference Glass-Metal
nickel-ironwire,commonlyknownasdumet,intendedprimar-
Bead-Seal
ily for sealing to soft glass.
1.2 The values stated in inch-pound units are to be regarded
3. Ordering Information
as standard. The values given in parentheses are mathematical
3.1 The wire is usually supplied with a surface coating
conversions to SI units that are provided for information only
consisting of a mixture of copper oxides and fused sodium
and are not considered standard.
tetraborate (borax) which retards oxidation of the wire during
1.3 This standard does not purport to address all of the
sealing in glass and further aids wetting of the wire by the
safety concerns, if any, associated with its use. It is the
glass. The composite wire may also be purchased as bare wire
responsibility of the user of this standard to establish appro-
for specific applications.
priate safety, health, and environmental practices and deter-
3.2 Thesizeofthewire,ifapplicable,theboratecolorrange
mine the applicability of regulatory limitations prior to use.
designated as light, medium (regular), or dark, shall be
1.4 This international standard was developed in accor-
specified on each purchase order.
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
3.3 Package sizes shall be agreed upon between the pur-
Development of International Standards, Guides and Recom-
chaser and the seller.
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
4. Chemical Composition
4.1 The copper used in the manufacture of dumet shall be
2. Referenced Documents
99.90% minimum copper. Silver shall be included with the
2.1 ASTM Standards:
copper. The material shall be free of reducible oxides.
B170Specification for Oxygen-Free Electrolytic Copper—
4.2 The chemical composition of the nickel-iron core shall
Refinery Shapes
be as shown in Table 1.
D1535Practice for Specifying Color by the Munsell System
D1729Practice for Visual Appraisal of Colors and Color
5. Oxide Coating
Differences of Diffusely-Illuminated Opaque Materials
E3Guide for Preparation of Metallographic Specimens
5.1 The primary standards for the entire range of colors are
E29Practice for Using Significant Digits in Test Data to dividedintothreegroupscoveringlight,medium(regular),and
Determine Conformance with Specifications
dark as shown, with their respective limits, in Fig. 1 and Table
E53Test Method for Determination of Copper in Unalloyed 2 (Note 1). The color range of the specimens shall be
Copper by Gravimetry (Withdrawn 2022)
determined in accordance with 9.2.
NOTE 1—Color chip 2.5R 3.90/8.0 may be included in the dark range
merely to extend the color series for assisting the viewer in making a
This specification is under the jurisdiction of ASTM-Committee F01 on
better decision regarding the cut-off point between medium (regular) and
Electronics and is the direct responsibility of Subcommittee F01.03 on Metallic
dark dumet.
Materials.
Current edition approved May 1, 2022. Published May 2022. Originally
approved in 1963. Last previous edition approved in 2017 as F29–97(2017). DOI:
6. Thermal Expansion
10.1520/F0029-97R22.
6.1 The nominal values for the average coefficient of linear
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
thermal expansion shall be as follows when determined in
Standards volume information, refer to the standard’s Document Summary page on
accordance with 9.1:
the ASTM website.
−7
6.1.1 Core—63 to 72×10 in./in.·deg °C (mm/mm·deg
The last approved version of this historical standard is referenced on
www.astm.org. °C) over the temperature range of 30 to 400°C.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F29−97 (2022)
TABLE 1 Chemical Requirements: Core Material
9.1.1 Heat the core rod specimen in a hydrogen atmosphere
Element Composition, % for1hat900°C; then cool it from 900 to 200 °C at a rate not
Nickel 41 to 43 exceeding 5°C/min.
Manganese 0.75 to 1.25
9.1.2 Determine the thermal expansion charateristics in
Silicon, max 0.30
accordance with Test Method E228.
Carbon, max 0.10
Sulfur, max 0.02
9.2 Color of Coating— Mount the color chips on a neutral
Phosphorus, max 0.02
Iron (by difference) remainder background (middle gray to white) as shown in Fig. 1. Wind
the specimen to be tested or compared on a flat surface similar
tothatshowninFig.1.Eachturnofthewireshouldlieparallel
TABLE 2 Color Ranges and Limits
and as close as possible to the preceding turn without overlap-
Medium (Regular)
ping. View the specimen in natural or artificial daylight in
Dark Range Light Range
Range
accordancewitheitherorbothMethodD1535,(Note3)orTest
Colors darker than chip 3.5R 3.5R 3.94/8.0 to 6.5R 7.5R 4.22/8.0 to 0.5YR
Method D1729, Fig. 2.
3.94/8.0 4.06/8.0, incl 4.56/8.0 incl
NOTE 3—Coated wire carries a mixture of copper oxides and fused
sodiumtetraborateonthesurfaceofthedumet,whichdissolves,whollyor
TABLE 3 Dimensional Tolerances in part, into the glass during the sealing operation. The sealing technique
is influenced by the amount of coating, and color has been established as
Diameter, in. (mm) Tolerance, in.
a means of estimating the thickness of this mixture.The color varies from
(mm)
a dark red-purple to a light yellow-red as the thickness decreases. The
0.007 to 0.013 (0.18 to 0.33) ±0.0003 (±0.008)
method,describedinTestMethodD1535,isbasedonthecolor-perception
Over 0.013 to 0.018 (0.33 to 0.46) ±0.0004 (±0.010)
attributes of hue, lightness, and saturation and is used as the means for
Over 0.018 (0.46) ±0.0005 (±0.013)
specifying color.This method employs the Munsell color-notation system
in which visual scales are assigned to each of the color-perception
attributes. In this system, the attributes are called hue, H, value, V, and
−7
6.1.2 Copper—177 6 3.5×10 in./in.·°C (mm/mm·deg
chroma,C,writt
...