1、Designation: D 4102 82 (Reapproved 2008)Standard Test Method forThermal Oxidative Resistance of Carbon Fibers1This standard is issued under the fixed designation D 4102; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of l
2、ast 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 test method covers the apparatus
3、and procedure forthe determination of the weight loss of carbon fibers, exposedto ambient hot air, as a means of characterizing their oxidativeresistance.1.2 The values stated in SI units are to be regarded asstandard. The values given in parentheses are mathematicalconversions to inch-pound units w
4、hich are provided for infor-mation only and are not considered standard.1.3 This standard does not purport to address all of thesafety concerns, 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 t
5、he applica-bility of regulatory limitations prior to use. For specific hazardinformation, see Section 8.2. Referenced Documents2.1 ASTM Standards:2C 613/C 613M Test Method for Constituent Content ofComposite Prepreg by Soxhlet Extraction3. Definitions3.1 carbon fibersfibers containing at least 90 %
6、carbon byweight made by pyrolysis from synthetic polymeric or pitchfibers and having moduli $70 GPa ($107psi).3.2 precursororganic fiber from which carbon fibers areprepared via pyrolysis. Polyacrylonitrile (PAN), rayon, andpitch are commonly used.3.3 fiber finishsurface coating applied to fibers to
7、 facili-tate handling or provide better wetting and compatibility offiber and matrix, or both.4. Summary of Test Method4.1 The test method is composed of two parts. The first onespecifies exposure conditions for an accelerated measurement,determining weight loss of the carbon fiber after 24 h in air
8、 at375C (707F). The second part specifies conditions for anextended measurement, determining the weight loss resultingfrom 500-h exposure in air at 315C (600F).5. Significance and Use5.1 The test is used to determine the oxidative resistances ofcarbon fibers as a means of selecting the most stable f
9、ibers forincorporation in high-temperature fiber-reinforced compositesystems. It can be used for quality control, material specifica-tion, and for research and development of improved carbonfibers. Factors that influence the oxidative resistance andshould be reported are fiber identification, precur
10、sor type, fibermodulus, and any information on impurities, particularlymetals. Also note that the presence of finish on the fiber canaffect the oxidative resistance, and thus, alternative specimenpreparations that enable the evaluation of finish effects areincluded.6. Apparatus6.1 Balance, capable o
11、f weighing to the nearest 0.1 mg.6.2 Vacuum Oven, capable of providing vacuum of 10 torr(1.3 kPa) or less at 80C (177F).6.3 Circulating Air Oven, with sufficient flow rate andcapability to change the ambient air in the chamber once aminute, while maintaining the temperature within 10C (18F)over the
12、25C (77F) to 375C (707F) range.6.4 Glass Beakers, borosilicate, 250-mL (8.45 oz) or othersize, appropriate for the oven (one per sample).6.5 Wire Mesh Covers, for the beakers to reduce excessiveair turbulence during the exposure.36.6 Boiling Flasks or Erlenmeyer Flasks, borosilicate glass,250- or 50
13、0-mL (8.45- or 16.91-oz) size, with standard-taperjoint.1This test method is under the jurisdiction of ASTM Committee D30 onComposite Materials and is the direct responsibility of Subcommittee D30.03 onConstituent/Precursor Properties.Current edition approved Nov. 1, 2008. Published December 2008. O
14、riginallyapproved in 1982. Last previous edition approved in 2004 as D 4102 82 (2004).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary
15、 page onthe ASTM website.320-mesh nickel-chromium wire gauze from Fisher Scientific Co. has beenfound satisfactory for this purpose.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.7 Glass Condensers, borosilicate for the above flas
16、ks.6.8 Hot Plate.6.9 Tweezers, stainless steel.7. Reagents and Materials7.1 Methyl Ethyl Ketone (2-butanone) 99.5 % pure, boilingrange 70.0 to 81.0C (158 to 177.8F), or other suitablesolvents recommended in Test Method C 613/C 613M.8. Hazards8.1 The methyl ethyl ketone, classified as an irritant and
17、 afire hazard, should be handled in a well-ventilated area andshould not be exposed to direct heat or open flame.9. Test Specimen and Sampling9.1 Using clean gloves to prevent any contamination, par-ticularly with salt, unwrap the outer layers, which may havebeen contaminated by previous handling or
18、 environmentalexposure, from the test package of carbon-fiber yarn anddiscard. Form a small coil of fresh fiber weighing approxi-mately 2 g around two gloved fingers and tuck the ends in toobtain a specimen in the form of an easily handleable loop.9.2 Number of SpecimensFor quality control purposes,
19、test a minimum of two specimens from each sample. For aquantitative assessment of the fiber performance, however, testa minimum of ten specimens and evaluate the results statisti-cally as described in 12.4.9.3 Finish Removal from the FiberMany carbon fibers arecoated with an organic finish to improv
20、e handleability, wetta-bility, and adhesion to the matrix. These materials are generallypresent at about 1 % levels and are usually not stable at theexposure temperatures prescribed herein. The finish, if present,may be removed by extraction with hot solvent, such as methylethyl ketone or dimethyl f
21、ormamide (DMF). Soxhlet extractionas described in Test Method C 613/C 613M is recommendedfor difficult-to-remove finishes and as a reference control.However, other finishes may be extracted by the proceduregiven in 11.3.1-11.3.4.9.4 Finish Left on the FiberSince the fiber will normallybe used with t
22、he finish intact, it is most useful to know theoxidative resistance of the fiber containing finish. To charac-terize and select fibers with optimum finishes, it is also veryuseful to know the relative effects of a variety of finishes. Forthis reason, it is desirable to have approaches for the determ
23、i-nation of oxidative resistance both with and without finish.10. Conditioning and Drying10.1 Place the test specimens, beakers, and gauze covers ina vacuum oven at 77C (170F) and dry for 16 h at a reducedpressure during the procedural steps described in 11.4.1 and11.4.2.11. Procedure11.1 Weigh each
24、 specimen as removed from the samplepackage to the nearest 0.1 mg. Record the initial weight, Wi.Inthis and all subsequent weighings, use clean dry stainless steeltweezers for the transfer of specimens.11.2 If finish is to be removed (see 9.3), then either use aSoxhlet extraction as recommended in T
25、est Method C 613/C 613M or follow Steps 11.3.1-11.3.4. If finish is not to beremoved, skip Steps 11.3.1-11.3.4 and proceed with Step 11.4.11.3 Removal of the Finish:11.3.1 Put the specimen in a dry flask and cover with 100 to200 mL (3.38 to 6.76 oz) of methyl ethyl ketone solvent. Placethe condenser
26、 onto the flask and start the cooling water. Heatthe flask on the hot plate or heating bath to bring the solvent toboil. Soak the specimen in the boiling solvent for 15 min. Takeoff the condenser, decant the solvent, and remove the speci-men.11.3.2 Dry the specimen in the vacuum oven at 77C(170F) at
27、 a reduced pressure of 10 torr (1.3 kPa) or less for 30min.11.3.3 Weigh the dried specimen to the nearest 0.1 mg.Record the weight.11.3.4 Repeat Steps 11.3.1-11.3.3 until the weight remainsconstant, within 60.1 mg. Record the final weight, We.11.4 Drying:11.4.1 Dry each specimen for 16 h in a vacuum
28、 oven at77C (170F) at a reduced pressure of 10 torr (1.3 kPa) or less.11.4.2 After drying, weigh the specimen to the nearest 0.1mg and record the weight, Wd. Weigh each specimen in a taredbeaker or crucible.11.5 TestingProcedure A (Short Term):11.5.1 Preheat the air oven to 375C (707F) and make sure
29、that the specimen positions in the oven are at 375 6 5C (7076 9F) at the air circulation rate specified in 6.3.11.5.2 Place the beakers with the specimens in the oven andrecord the starting time.11.5.3 After 24.0 h remove the specimens from the oven,cool in a desiccator, weigh to the nearest 0.1 mg,
30、 and record theweight, Wa.11.6 TestingProcedure B (Long-Term):11.6.1 Preheat the air oven to 315C (600F) and make surethat the specimen positions in the oven are at 315 6 5C (6006 9F) at the air circulation rate specified in 6.3.11.6.2 Place the beakers with the specimens in the oven andrecord the s
31、tarting time.11.6.3 After 500.0 h, remove the specimens and containersfrom the oven, cool in a dry atmosphere, weigh the specimensto the nearest 0.1 mg, and record the weight, Wa. (Weightlosses can be obtained at intermediate times to obtain rateinformation.)12. Calculations12.1 Fiber FinishDetermin
32、e the amount of finish, inweight percent, as follows:Wf5 Wi2 We/Wi! 3 100 (1)where:Wf= percent finish on the fiber,Wi= specimen weight before finish removal, mg, andWe= final specimen weight after the finish removal, as in11.3.4, mg.D 4102 82 (2008)212.2 Weight Loss in DryingCalculate the weight los
33、s indrying as follows:Wdr5 We2 Wd/ We! 3 100, or (2)Wi2 Wd/Wi! 3 100where:Wdr= percent weight loss in drying,We=asin12.1,Wi=asin12.1, andWd= specimen weight after drying, as in 11.4.2, mg.12.3 Weight Loss in Air OxidationCalculate the relativeoxidative weight loss, in weight percent, as follows:Wh5
34、Wd2 Wa/Wd! 3 100 (3)where:Wh= percent weight loss in hot air,Wa= specimen weight after the hot air exposure, mg, andWd=asin12.2.12.4 Statistical EvaluationCalculate the average, X, thestandard deviation, s, and the coefficient of variation, % CV, foreach sample, comprised of ten or more tested speci
35、mens, asfollows:X 5(i 5 1nXiN(4)s 5F(i 5 1NXi2 X!2N 2 1G1/2%CV5 s/X! 3 100where:N = number of test specimens, $10, andXi= weight loss of the ith specimen.13. Report13.1 The report shall include the following:13.1.1 Complete identification of the material evaluated,including fiber type, source, manuf
36、acturers code number(s)form, previous history, precursor type, type and nature offinish, and levels of impurities, if known.13.1.2 Finish removal and conditioning procedures, if otherthan specified herein.13.1.3 Number of specimens tested for given sample.13.1.4 Identification of the test procedure
37、used.13.1.5 Weight loss in drying; average value, and standarddeviation plus coefficient of variation if N $ 10.13.1.6 Percent finish on the fiber; average value, standarddeviation, and coefficient of variation if N $ 10.13.1.7 Percent weight loss in air; average value, standarddeviation, and coeffi
38、cient of variation if N $ 10.13.1.8 Date of test.14. Precision and Accuracy14.1 No estimate of accuracy can be offered as no acceptedreference level is available. The precision, defined as thedegree of mutual agreement between individual measurements,cannot yet be estimated because of insufficient a
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42、e 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 States. 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).D 4102 82 (2008)3
