1、Designation: D4018 17Standard Test Methods forProperties of Continuous Filament Carbon and GraphiteFiber Tows1This standard is issued under the fixed designation D4018; 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 U.S. Department of Defense.1. Scope1.1 These test methods cover the prepa
3、ration and tensiletesting of resin-impregnated and consolidated test specimensmade from continuous filament carbon and graphite yarns,rovings, and tows to determine their tensile properties.1.2 These test methods also cover the determination of thedensity and mass per unit length of the yarn, roving
4、, or tow toprovide supplementary data for tensile property calculation.1.3 These test methods include a procedure for sizingremoval to provide the preferred desized fiber samples fordensity measurement. This procedure may also be used todetermine the weight percent sizing.1.4 These test methods incl
5、ude a procedure for determiningthe weight percent moisture adsorption of carbon or graphitefiber.1.5 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.1.6 This standard does not purport to address all of thesafety concerns, if any
6、, 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.2. Referenced Documents2.1 ASTM Standards:2D70 Test Method for Density of Semi-Solid Bituminou
7、sMaterials (Pycnometer Method)D1193 Specification for Reagent WaterD3800 Test Method for Density of High-Modulus FibersD5550 Test Method for Specific Gravity of Soil Solids byGas PycnometerE4 Practices for Force Verification of Testing MachinesE83 Practice for Verification and Classification of Exte
8、n-someter Systems2.2 Other Document:CRC Handbook of Chemistry and Physics33. Terminology3.1 Definitions:3.1.1 sizing, na generic term for compounds which, whenapplied to yarn or fabric, form a more or less continuous solidfilm around the yarn and individual fibers.3.2 Definitions of Terms Specific t
9、o This Standard:3.2.1 desized fiber, nfiber which has had a sizing removedfrom it.3.2.2 fiber, ncontinuous filament carbon or graphite yarn,roving, or tow.3.2.3 sized fiber, na fiber with a sizing applied to it.3.2.4 unsized fiber, nfiber which has never had a sizingapplied to it.3.3 Symbols:3.3.1 A
10、Unit conversion factor for tensile strength3.3.2 BUnit conversion factor for tensile modulus3.3.3 Efiber chord modulus3.3.4 lLower strain limit3.3.5 uUpper strain limit3.3.6 kccorrection factor for density of size3.3.7 Lspecimen length3.3.8 MULthe mass per unit length of the sized fiber3.3.9 MULIthe
11、 mass per unit length of the impregnatedand consolidated fiber3.3.10 Pmaximum load3.3.11 Pltensile load at lower strain limit1These test methods are under the jurisdiction of ASTM Committee D30 onComposite Materials and are the direct responsibility of Subcommittee D30.03 onConstituent/Precursor Pro
12、perties.Current edition approved Jan. 15, 2017. Published January 2017. Originallyapproved in 1981. Last previous edition approved in 2011 as D4018 11. DOI:10.1520/D4018-17.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For A
13、nnual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3CRC Press Inc., Boca Raton, Ann Arbor, London, Tokyo, 73rd Edition,19921993.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United Stat
14、esThis international standard was developed 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 Tra
15、de (TBT) Committee.13.3.12 Putensile load at upper strain limit3.3.13 fdensity of the fiber3.3.14 sfdensity of the fiber with sizing3.3.15 RCweight percent of resin (resin content)3.3.16 W1specimen mass4. Summary of Test Methods4.1 These test methods include procedures for determiningthe tensile str
16、ength and modulus of a resin-impregnated andconsolidated carbon fiber tow. Also included are procedures tomeasure the mass per unit length and density of the carbonfiber and the resin content of the resin-impregnated andconsolidated specimens.4.2 MULThe MUL of the fiber is determined by dividingthe
17、mass of a sample of sized fiber by its length.4.3 DensityThe density of the fiber is determined usingArchimedes method or a pycnometer method. The recom-mended specimen is desized or unsized fiber. The idealimmersion fluid is one that completely wets the specimen andprovides minimum toxicity or envi
18、ronmental hazard.4.4 Resin ContentThe resin content (weight percent) ofthe resin-impregnated and consolidated fiber is determined bycomparing the mass per unit length of the impregnated andconsolidated specimen to the fiber mass per unit length.4.5 Tensile PropertiesThe tensile strength and tensilec
19、hord modulus of the fiber are determined by the tensileloading to failure of the resin-impregnated and consolidatedfiber. The chord modulus is determined between defined strainlimits. The purpose of the impregnating resin is to provide thefiber, when consolidated, with sufficient mechanical strength
20、 toproduce an easily handled test specimen capable of sustaininguniform loading of the individual filaments in the specimen.The resin shall be compatible with the fiber and any sizeapplied to it. The strain capability of the consolidated resinshall be at least twice the strain capability of the fibe
21、r.5. Significance and Use5.1 The properties determined by these test methods are ofvalue in material specifications, qualifications, data basegeneration, certification, research, and development.5.2 These test methods are intended for the testing of fibersthat have been specifically developed for us
22、e as reinforcingagents in advanced composite structures. The test results of animpregnated and consolidated fiber should be representative ofthe strength and modulus that are available in the materialwhen used as intended. The performance of fibers in differentresin systems can vary significantly so
23、 that correlations be-tween results using these test methods and composite testingmay not always be obtained.5.3 The reproducibility of test results is dependent uponprecise control over all test conditions. Resin type, content anddistribution, curing process, filament alignment, gripping in thetest
24、ing machine, and alignment in the testing machine are ofspecial importance.5.4 The measured strengths of fibers are not unique quan-tities and test results are strongly dependent on the test methodsused. Therefore the test method described here will notnecessarily give the same mean strengths or sta
25、ndard devia-tions as those obtained from single filaments, dry fibers,composite laminas, or composite laminates.6. Apparatus6.1 Three sets of apparatus are required. One set is for resinimpregnation of the fiber. A second set is for curing theresin-impregnated specimens. A third set is for tensile t
26、estingthe resin-impregnated and consolidated specimens. Optionalapparatus may be used for applying end tabs to the specimensand removing sizing.6.1.1 Resin ImpregnationThe goal of the resin-impregnation apparatus is to apply and uniformly impregnateresin into the fiber. This is normally achieved by
27、dipping thefiber into the resin and then working the wet fiber over rolls orthrough a die, or both. While automated apparatuses arepreferred for consistency, any apparatus which achieves uni-form impregnation of 35 to 60 % resin by weight and does notdamage the fiber is acceptable.6.1.2 Consolidatio
28、nAn apparatus to hold the impregnatedspecimens under tension during consolidation is required.6.1.3 Optional End TabsAn apparatus to cast resin endtabs on specimens may be used.Apparatuses to apply and alignother forms of end tabs such as bonded on cardboard or metaltabs may also be used.6.1.4 Testi
29、ngA tensile testing machine and recorder meet-ing the requirements of Practices E4 at the maximum expectedtest load are required. The load recording device shall becoordinated with the extensometer and strain recorder to assurethat the corresponding load and elongation of the specimen arerecorded at
30、 essentially the same time. The testing machineshall also have the following features:6.1.4.1 GripsGrips suitable for loading the tabbed oruntabbed specimen without damaging it are required. For resintabbed specimens a custom grip is generally required. Foruntabbed or cardboard tabbed specimens pneu
31、matic or hydrau-lically powered grips are typically used. Different grip pressuresettings may be required for different fibers.6.1.4.2 JawsJaws compatible with the grips and capableof holding a specimen without damaging it are required. Foruntabbed specimens, flat jaws with rubber or other compliant
32、materials bonded to the face are generally used. Sandpapermay also be placed on the grips to reduce slippage. Forcardboard tabbed specimens serrated jaws are generally used.Jaws should be inspected regularly and cleaned or repaired asrequired.6.1.4.3 Extensometer and RecorderAn extensometer andrecor
33、ding device in accordance with the requirements ofPractice E83 Class B-2 are required. The extensometer andrecorder shall be coordinated with the tensile testing machineso that the corresponding load and elongation of the specimenare recorded at essentially the same time.6.1.4.4 Balance, AnalyticalA
34、ccuracy of 6 0.0002 g formass per unit length, density, and resin or size contentdeterminations.D4018 1726.1.4.5 Balance, LaboratoryAccuracy of 6 0.1 g formeasuring components of resin.6.1.4.6 Length Measuring DevicesDevices to measure thelength of impregnated and consolidated specimens and dryfiber
35、 to 6 2 mm accuracy are required.6.1.4.7 Density Measuring DeviceSee Test Methods D70,D3800,orD5550.6.1.4.8 Forced Air OvenA forced air oven of sufficientsize and temperature capabilities to cure the impregnated fiberon the curing device. The temperature shall be controlled to610C.7. Reagents and Ma
36、terials7.1 Reagent WaterUnless otherwise indicated, referencesto water shall be understood to mean reagent water as definedby Type III of Specification D1193.7.2 Resin.7.3 Commercial Grade Solvent, (optional) for resin dilution.7.4 Hardener or Catalyst.7.5 Surfactant (optional).8. Test Specimens8.1
37、Mass per Unit Length SpecimenThe specimen tomeasure mass per unit length isa1mminimum length of fiberin the form in which it is intended to be used. Test onespecimen per sample. Coil the specimen into a usable form fortesting. Care is required to not damage and lose filaments fromthe specimen.8.2 De
38、nsity SpecimenDensity specimens may be sized,unsized, or desized material. Unsized or desized samples arepreferred. Test one specimen per sample. A 1 m minimumlength is required for Test Method D3800. For methods in TestMethods D70 and D5550, a suitable volume to fill thecontainer is recommended. Co
39、il the specimen into a usableform for testing. Care is required to not damage and losefilaments from the specimen.8.3 Tensile Test SpecimenThe tensile specimen shall be atabbed or untabbed resin-impregnated and consolidated fiber.Tabbed specimens shall have a 150 6 5 mm gage lengthbetween the tabs.
40、Untabbed specimens shall be of sufficientlength to allow a 150 6 5 mm gage length between the gripswhen they are tested. Samples with 3000 filaments or less maybe tested using specimens of more than one fiber bundle tofacilitate handling. Combine the bundles before resin impreg-nation and count the
41、test results as one specimen. Test aminimum of four test specimens per sample. Separate testspecimens for modulus and strength determination are permit-ted; however, four specimens for each test are required.Specimens that are fuzzy, curved, not uniform in cross section,have broken filaments, resin
42、lumps, or other observable defectsshould be rejected unless they are representative of the materialbeing tested.9. Conditioning9.1 Fibers that adsorb less than 0.5 % moisture by weight at23 6 2C and 90 % or greater relative humidity require noconditioning before testing. Conduct mass per unit length
43、,density, and tensile testing for these materials at 23 6 7C and50 6 20 % relative humidity unless other conditions are thevariables of interest.9.2 Fibers that adsorb more than 0.5 % moisture by weightat 23 6 2C and 90 % or greater relative humidity requireconditioning before testing. Condition fib
44、ers at 23 6 2C and50 6 10 % relative humidity for a minimum of 24 h. Conductmass per unit length and density testing at 23 6 2C and 50 610 % relative humidity unless other conditions are the vari-ables of interest. Conduct tensile testing at 23 6 7C and 50 610 % relative humidity unless other condit
45、ions are the vari-ables of interest.9.3 To determine moisture adsorption, dry a minimum offive mass per unit-type specimens at 120 6 5C for 24 h in acirculating air oven. Cool samples in a desiccator. Removesamples from desiccator one at a time and immediately weighthem. Place samples in a humidity
46、chamber and maintain at 236 2C and 90 % or greater relative humidity for 24 h. Removesamples from the humidity chamber one at a time and weighimmediately.9.4 If all specimens are conditioned for 24 h and mass perunit length and density testing are performed at 23 6 2C and50 6 10 % relative humidity,
47、 then no testing for moistureadsorption is required.9.5 Moisture adsorption testing is only required once annu-ally for a standard product.10. Specimen Preparation10.1 Mass per Unit LengthNo preparation is required.Thesample is taken from a package of material as it is intended tobe used.10.2 Densit
48、yThe preferred density specimen is a desizedor unsized fiber. This eliminates any need to correct for thedensity of the sizing. The sizing may be removed using solventextraction, pyrolysis, or other means. An example method isdescribed in Appendix X1. An unsized sample of a sized fiberwould have to
49、be collected during the production of the fiberand is therefore not recommended.10.3 Tensile TestThe tensile test specimen must be im-pregnated with resin and consolidated before testing.10.3.1 Resin PreparationAny resin that meets the require-ments of 4.5 may be used. The resin when combined with thefiber shall produce a composite (reinforcement/matrix) failure.A resin generally found satisfactory is a combination ofbisphenolA(or bisphenol F) epoxy and diethyltoluene diaminein the weight ratio of 3.9:1. A solvent that low
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