1、Designation: F 288 96 (Reapproved 2009)Standard Specification forTungsten Wire for Electron Devices and Lamps1This standard is issued under the fixed designation F 288; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of la
2、st revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This specification covers three types o
3、f drawn wiresuitable for fabrication into parts for electron tubes, lamps, andother devices; and one type of rod for metal-to-glass sealing(grid wire is excepted):1.1.1 Type 1ACommercially pure nonsag wire (Note 2and Note 3).1.1.2 Type 1BCommercially pure rod suitable for metal-to-glass sealing.1.1.
4、3 Type 2AThoriated filament wire containing 1 %thoria.1.1.4 Type 2BThoriated filament wire containing 2 %thoria.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 a
5、re not considered standard.1.3 Types 1A and 1B are designated as UNS R07005. Type2A is designated as UNS R07911. Type 2B is designated asUNS R07912.1.4 The following precautionary caveat pertains only to theChemical Analysis, Section 12 of this specification: Thisstandard does not purport to address
6、 all of the safety concerns,if any, associated with its use. It is the responsibility of the userof this standard to establish appropriate safety and healthpractices and determine the applicability of regulatory limita-tions prior to use.NOTE 1A dimensional measurement method for testing nonsag tung
7、-sten wire above 0.030 in. (0.76 mm) in diameter is provided in TestMethod F 269.NOTE 2Acceptance of nonsag wire characteristics for particularapplications of size shall be by agreement between producer and consumerbased on either a flashed microstructure as shown by photomicrographs,or on dimension
8、al measurement limits determined in accordance with TestMethod F 269.2. Referenced Documents2.1 ASTM Standards:2F16 Test Methods for Measuring Diameter or Thickness ofWire and Ribbon for Electronic Devices and LampsF 204 Test Method for Surface Flaws in Tungsten Seal Rodand WireF 205 Test Method for
9、 Measuring Diameter of Fine Wire byWeighingF 219 Test Methods of Testing Fine Round and Flat Wirefor Electron Devices and LampsF 269 Test Method for Sag of Tungsten Wire2.2 Military Standards:MIL-STD-105 Sampling Procedures and Tables for Inspec-tion by Attributes3MIL-STD-129 Marking for Shipment an
10、d Storage33. Terminology3.1 Definition of Terms Specific to This Standard:3.1.1 wireThe term wire as used in this specificationapplies to all drawn material that is spooled or coiled, and toshort cut lengths 0.020 in. (0.51 mm) or less in diameter.3.1.2 nonsag or doped tungsten wireThis term designa
11、tesa wire which, when recrystallized, shows elongated interlock-ing grains.3.1.3 rodThe term rod as used in this specification appliesto centerless ground material 0.020 in. (0.51 mm) or larger indiameter, in short cut lengths or random cut lengths.4. Ordering Information4.1 Orders for wire and rod
12、furnished to this specificationshall include the following information:4.1.1 Length in metres, or quantity of short cut lengths,4.1.2 Type and UNS No. (Section 1),4.1.3 Straightness (Section 10),1This specification is under the jurisdiction of ASTM Committee F01 onElectronics and is the direct respo
13、nsibility of Subcommittee F01.03 on MetallicMaterials.Current edition approved May 1, 2009. Published July 2009. Originally approvedin 1954. Last previous edition approved in 2002 as F 288 96 (2002).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service
14、 at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from Standardization Documents Order Desk, Bldg. 4 Section D, 700Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS.1Copyright ASTM International,
15、100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.1.4 Finish (Section 8),4.1.5 Weight or size (Section 7) and tolerance, and4.1.6 Specification number.NOTE 3A typical ordering description for straight chemically cleanedwire is as follows: xxxx metres, tungsten wir
16、e, Type 1A UNS R07005,straightened, Finish 2; 280.8 mg/200 mm (63 %), to ASTM F288 XX.5. Chemical Composition5.1 The wire and rod shall conform to the chemical require-ments specified in Table 1. The sample for analysis shall berepresentative of the lot submitted. Lot size, sample size, andsampling
17、method shall be as agreed upon by the supplier andpurchaser.6. Physical Properties6.1 Tensile StrengthThe tensile strength of a 10-in. (250-mm) gage length of wire in grams per milligram per 200 mmshall be within the limits specified in Table 2 when tested inaccordance with 13.1.6.2 General Ductilit
18、y RequirementsThe ductility of Types1A, 2A, and 2B wire shall be sufficient to meet the followingrequirements:6.2.1 Wire up to 75 mg/200 mm, InclusiveSix 1-m lengthsshall be tested in accordance with 13.2. The wire shall notbreak more than two times in the six tests. Where required, alower limit may
19、 be negotiated between purchaser and seller.6.2.2 Wire over 75 mg/200 mmThirty successive close-wound turns completely around mandrels shall be free ofsplitting or cracking when tested in accordance with 13.2.2 andexamined at a magnification of 303.6.2.3 Special Ductility RequirementsWire for certai
20、n ap-plications may require a special ductility as agreed uponbetween the purchaser and the seller.6.3 Surface DefectsType 1B rod shall not show faultswhen tested in accordance with 13.5.7. Dimensions, Weights, and Permissible Variations7.1 Dimensional tolerances for Type 1A (nonsag) wire foruse as
21、incandescent filaments shall conform to the require-ments specified in Table 3.NOTE 4Tolerances are industry standards; closer tolerances may beobtained in certain instances, usually at a premium.7.2 Out-of-roundness of wire or rod over 0.020 in. (0.51mm) in diameter shall be within 5 % of the maxim
22、um diameter,when measured by a method agreed upon by supplier andpurchaser. A referee method for this test is contained inProcedure B of Test Methods F16.7.3 Weight/Diameter Conversion Formulas:7.3.1 The weight of Type 1A wire and Type 1B rod (density19.17), is as follows:wt in mg/200 mm 5diameter i
23、n mils!23 1.943, ordiameter in mm!23 30117.3.2 The weight of Type 2A wire (density 18.80), is asfollows:wt in mg/200 mm 5diameter in mils!23 1.905, ordiameter in mm!23 29537.3.3 The weight of Type 2B wire (density 18.50), is asfollows:wt in mg/200 mm 5diameter in mils!23 1.875, ordiameter in mm!23 2
24、9068. Workmanship, Finish, and Appearance8.1 Furnish the wire in the following finishes:8.1.1 Finish 1Black, as-drawn,8.1.2 Finish 2Chemically cleaned,8.1.3 Finish 3Chemically cleaned and stress-relieved.8.1.4 Finish 4Reducing atmosphere cleaned and an-nealed,8.1.5 Finish 5Etched, and8.1.6 Finish 6E
25、lectropolished.8.2 The rod shall be furnished in the following finish:8.2.1 Finish 7Centerless ground.9. General Requirements9.1 The material shall be smooth, free of twists, bends,kinks, curls, and as free of dents, swaging marks, scratches, diemarks, laps, seams, splits, slivers, inclusions, bumps
26、, pits,grooves, cracks, and other physical defects when examined ata magnification of 303 as best commercial practice willpermit.9.2 Unless black finish is specified, all types of wire shallhave a clean finish, free of graphite, grease, oil, and lubricants.All finishes shall be as free of dirt, oxid
27、e, stains, scale, andother surface defects, as best commercial practice permits.Wire for hooks, supports, springs, anchors, and mesh shallhave a bright smooth surface free of cracks, holes, or craterswhen examined at a magnification of 103.9.3 Rod of Type 1B shall have a bright smooth surface andbe
28、capable of making acceptable metal-to-glass seals whentested in accordance with Test Method F 204.10. Straightness10.1 When ordered as straightened, straightness of wire3.00 mg/200 mm and larger shall be specified as the radius ofcurvature or camber of a given length of wire as agreed uponbetween th
29、e purchaser and supplier. For wire under 3.00mg/200 mm, alternative methods for straightness requirementsmay be used as agreed upon between the purchaser and thesupplier.TABLE 1 Chemical RequirementsAType, Thoria, weight Tungsten, weightUNS number % %1A and 1B (R07005) 99.95 min2A (R07911) 0.8 min,
30、1.2 max balance2B (R07912) 1.7 min, 2.2 max balanceAFor all Types:Other elements (each)100 ppm max.Total other elements500 ppm max.F 288 96 (2009)211. Coiling and Spooling11.1 Spools and bands shall be clean and free of open seamsor projections which might catch or tangle the wire duringwinding or u
31、nwinding.11.2 Wire shall be furnished in one continuous length andwound smoothly with no loose turns. There shall be no pilingup of turns such as to prevent free unwinding or cause kinks orbends when the wire is removed from the spool. The outer endshall be attached firmly to the spool or band by su
32、itable means.11.3 Spool and band dimensions are shown in Table 4.11.4 Except for Finishes 5 and 6, no spools or bands in anyone shipment shall contain less than 300 m of wire for sizes upto 35 mg/200 mm; not less than 200 m of wire between 35 and50 mg/200 mm, and not less than 100 m between 50 and 1
33、00mg/200 mm. For wire sizes above 100 mg/200 mm each spoolor band shall contain no less than 50 g, minimum weight, ofwire.12. Chemical Analysis12.1 PurityDetermine purity gravimetrically or by a com-bination of spectrochemical and gravimetric analyses.12.2 Thoria ContentTransfer approximately 0.5 to
34、 1.0 gof the wire (weighed to the fourth decimal place) to a cleanporcelain boat. Place the boat in the combustion tube and bringthe temperature up to 600 to 700C. While the furnace is beingbrought to that temperature, pass a slow stream of air throughthe tube. When a temperature of approximately 60
35、0C has beenreached inside the tube, introduce a flow of hydrochloric acid(HCl) gas (Note 5) along with the air. Maintain a temperatureof 600 to 700C and continue the flow of HCl gas and air untilall the tungsten has been volatilized and only the white powderof thoria remains (Note 6). The thoria may
36、 be transferred to abalance pan for weighing, or weighed in the boat. If it isweighed in the boat, the weight of the boat should bedetermined both before and after the heating period, to correctfor any loss of weight by the boat during its stay in the furnace.Calculate the thoria content as follows:
37、Thoria, % 5mg of thoria/mg of sample!3100NOTE 5Hydrochloric acid (HCl) gas can be produced by dripping,from a separatory funnel, concentrated sulfuric acid on sodium chloride ina flask. (The optimum ratio of HCl gas to air and the optimum total gasflow through the tube have not been determined. A ra
38、te of approximatelyTABLE 2 Tensile Properties of Nonsag Tungsten Wire (Type 1A)AWeight of Wire, mg/200 mmDiameter of Wire, in.(mm, Approximate)Tensile Strength, g/mg/200 mmHigh TensileWire(Finishes1 and 2)MediumTensile Wire(Finish 3)Low TensileWire(Finish 4)Min Max Min Max Min MaxUp to 1.95 Up to 0.
39、001 (0.03), incl 80 110 70 90 55 95Over 1.95 to 7.91, incl Over 0.001 to 0.002 (0.030.05, incl) 75 105 70 90 55 90Over 7.91 to 17.60, incl Over 0.002 to 0.003 (0.050.08, incl) 70 100 60 90 55 90Over 17.60 to 48.25, inclOver 48.25 to 198.00, inclOver 198.00 to 760.00, inclOver 0.003 to 0.005 (0.080.1
40、3), inclOver 0.005 to 0.0010 (0.130.25), inclOver 0.010 to 0.020 (0.250.51), incl65605095908060605585858050508585ATensile properties for Types 2A and 2B wire are governed by the ductility requirements specified in 6.2.TABLE 3 Permissible Variations in Weight and Size for All Types of Wire and RodWei
41、ght of Wire, mg/200 mm Dimensional TolerancesSize Uniformity Within aSpoolUp to 0.36 60.02 mg/200 mm 0.02 mg/200 mmOver 0.36 to 0.67, incl 60.03 mg/200 mm 0.02 mg/200 mmOver 0.67 to 2.0, incl 63 weight % 0.02 mg/200 mmOver 2.0 to 760.0, incl 63 weight % 1 weight %Over 760.0 61.5 % of diameter .TABLE
42、 4 Size of Spool, Band, or CoilFlange or Head Diameter,in. (mm)Mandrel or Hub Diameter,in. (mm)Inside or Hole Diameter,in. (mm)ATraverse,in. (mm)0.715 to 0.785 0.580 to 0.605 0.437 to 0.450 0.420 to 0.435(18to20) (15to15) (11to11) (11to11)0.745 to 0.755 0.620 to 0.630 0.250 to 0.260 0.620 to 0.630(1
43、9 to 19) (16 to 16) (6 to 7) (16 to 16)1.88 to 2.38 1.13 to 1.63 0.340 to 0.375 0.75 to 1.0(48 to 60) (29 to 41) (8.6 to 9.5) (19 to 25)3.50 to 4.63 3.0 to 4.13 0.375 0.625(89 to 118) (76 to 105) (9.5) (16)4.0 to 4.75 3.88 to 4.0 3.50 to 3.88 0.75 to 1.0(102 to 121) (98 to 102) (89 to 98) (19 to 25)
44、AExcept on conical chamfered center mount spools.F 288 96 (2009)3three bubbles of HCl gas per second has been found satisfactory.)NOTE 6In the ordinary carbon furnace two samples can be runsimultaneously. The approximate time for volatilization is 5 h.13. Test Methods13.1 Tensile StrengthDetermine t
45、he tensile strength of thewire in accordance with Test Methods F 219. Use a flat blackbackground when testing fine wire below 0.005 in. (0.13 mm)in diameter.13.2 DuctilityDetermine the ductility of the wire as fol-lows:13.2.1 Wire up to 75 mg/200 mm, InclusiveDraw the wireover a 90 steel bar edge ha
46、ving a radius approximately equalto the diameter of the wire to be tested. Hold the wire againstthe edge of the bar with the thumb and draw the wire at anangle of 45 to the bar edge at a rate of approximately 1 m/suntil the tension on the wire is sufficient to cause a tight helicalcoil to be formed
47、after the tension is released.13.2.2 Wire over 75 mg/200 mmWind 30 successiveclose-wound turns completely around mandrels of sizes asspecified in Table 5 at the recommended forming temperatures.13.3 Visual InspectionCheck conformance of the wire tothe requirements specified in 9.2 by visual inspecti
48、on, exceptthat wire for hooks, supports, springs, anchors, and mesh shallbe checked with a magnification of 103.NOTE 7Orders placed by agencies of the U.S. government requirespecial acceptance criteria applied to visual inspection (13.3) and dimen-sional measurement (13.4). In these instances, sampl
49、es shall be selectedfor examination in accordance with MIL-STD-105 at Inspection Level I.The acceptance quality level (AQL) shall be 1.5 % defective. A unit shallbe one reel, coil, band, or spool of wire.13.4 Dimensional MeasurementsDetermine the size anduniformity of wire up to 760 mg/200 mm in accordance withTest Method F 205 (Note 7).13.5 Surface Flaws, Type 1BExamination of randomlengths and cut lengths of seal rod for surface flaws shall beconducted in accordance with Test Method F 204. A fault shallconsist of a tungste
