1、Designation: D 3171 06Standard Test Methods forConstituent Content of Composite Materials1This standard is issued under the fixed designation D 3171; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A numb
2、er in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) 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 These test methods determine the constituent content ofco
3、mposite materials by one of two approaches. Method Iphysically removes the matrix by digestion or ignition by oneof seven procedures, leaving the reinforcement essentiallyunaffected and thus allowing calculation of reinforcement ormatrix content (by weight or volume) as well as percent voidvolume. M
4、ethod II, applicable only to laminate materials ofknown fiber areal weight, calculates reinforcement or matrixcontent (by weight or volume), and the cured ply thickness,based on the measured thickness of the laminate. Method II isnot applicable to the measurement of void volume.1.1.1 These test meth
5、ods are primarily intended for two-partcomposite material systems. However, special provisions canbe made to extend these test methods to filled material systemswith more than two constituents, though not all test results canbe determined in every case.1.1.2 The procedures contained within have been
6、 designedto be particularly effective for certain classes of polymer ormetal matrices. The suggested applications are discussed inSection 4, as well as at the start of each procedure.1.1.3 Method I assumes that the reinforcement is essentiallyunaffected by the digestion or ignition medium. A procedu
7、refor correction of the results for minor changes in the reinforce-ment is included. Procedures A through F are based onchemical removal of the matrix while Procedure G removes thematrix by igniting the matrix in a furnace.1.1.4 Method II assumes that the fiber areal weight of thereinforcement mater
8、ial form is known or controlled to anacceptable tolerance. The presence of voids is not measured.Eq 9 and 10 assume zero void content to perform thecalculation.1.2 The SI units shown are considered standard.1.3 This standard does not purport to address all of thesafety concerns, if any, associated w
9、ith 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. See Section 9 foradditional information.2. Referenced Documents2.1 ASTM Standards:2D 792 Test Methods for D
10、ensity and Specific Gravity (Rela-tive Density) of Plastics by DisplacementD 883 Terminology Relating to PlasticsD 1505 Test Method for Density of Plastics by the Density-Gradient TechniqueD 3878 Terminology for Composite MaterialsD 5229/D 5229M Test Method for Moisture AbsorptionProperties and Equi
11、librium Conditioning of Polymer Ma-trix Composite MaterialsE12 Terminology Relating to Density and Specific Gravityof Solids, Liquids, and Gases3E 177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE 1309 Guide for Identification of Fiber-ReinforcedPolymer-Matrix Composite Mater
12、ials in Databases3. Terminology3.1 DefinitionsTerminology D 3878 defines terms relatingto composite materials. Terminology D 883 defines termsrelating to plastics. Terminology E 12 defines terms relating tospecific gravity. Practice E 177 defines terms relating tostatistics. In the event of a confli
13、ct between terms, TerminologyD 3878 shall have precedence over other documents.3.1.1 fiber content, nthe amount of fiber present in acomposite or prepreg expressed either as percent by weight orpercent by volume. This is sometimes stated as a fraction. If nofillers exist, this is equivalent to reinf
14、orcement content.D 38783.1.2 matrix content, nthe amount of matrix present in acomposite or prepreg expressed either as percent by weight orpercent by volume. For polymer matrix composites this is resincontent. D 38781These test methods are under the jurisdiction of ASTM Committee D30 onComposite Ma
15、terials and are the direct responsibility of Subcommittee D30.04 onLamina and Laminate Test Methods.Current edition approved April 1, 2006. Published April 2006. Originallyapproved in 1973. Last previous edition approved in 2004 as D 3171 99 (2004).2For referenced ASTM standards, visit the ASTM webs
16、ite, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Withdrawn.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,
17、United States.3.1.3 reinforcement content, nthe amount of nonmatrixmaterial (fiber and filler) in a composite or prepreg expressedeither as percent by weight or percent by volume. D 38783.1.4 resin content, nSee matrix content. D 38783.1.5 void volume, nthe volume in the specimen withoutmass, that i
18、s identified as neither matrix nor reinforcement.D 38783.2 Definitions of Terms Specific to This Standard:3.2.1 density, r23Cthe weight per unit volume measuredin air, of the impermeable portion of a material at 23C.3.2.1.1 DiscussionThe definition of specific gravity anddensity are essentially equi
19、valent to the definitions of apparentspecific gravity and apparent density in Terminology E 12,because no correction is made for buoyancy of the material inair. However, this difference is insignificant for most engineer-ing purposes.3.2.2 specific gravity, SG23Cthe ratio of the weight in airof a un
20、it volume of the impermeable portion of a material at23C referenced to the standard unit volume weight of water at23C.3.3 Symbols:A = area of the specimen.Ar= calculated mass of one layer of reinforcement/unitarea.rc= density of the composite specimen.rm= density of the cured matrix.rr= density of t
21、he reinforcement or fiber.h = thickness of the specimen.hp= cured ply thickness, mm.Mc= mass of the dry crucible or sintered glass filter.Mcr= mass of the dry crucible or sintered glass filter withreinforcement residue.Mi= initial mass of specimen before digestion or com-bustion.Mf= final mass of sp
22、ecimen after digestion or combus-tion.Np= number of plies in the laminate.Vm= volume percent of matrix in specimen.Vr= volume percent of reinforcement in the specimen.Vv= void volume percent in the specimen.Wm= weight percent of matrix in the specimen.Wr= weight percent of reinforcement in the speci
23、men.4. Summary of Test Method4.1 Test Method IThe matrix portion of a material speci-men of known mass is removed in a hot liquid medium (fordissolution) or furnace (for combustion). When dissolving in ahot liquid medium,the remaining residue, containing the rein-forcement, is then filtered, washed,
24、 dried, cooled, and weighed.The weight percent of the reinforcement is calculated, andfrom this value, and if densities of both the composite and thereinforcement are known, the volume percent is calculated. Anadditional calculation for void volume may be made if thedensity of the matrix is known or
25、 determined.4.1.1 Acorrection for weight change of the reinforcement orretention of the matrix may be made (13.3 and 13.4), if thischange is sufficiently reproducible under the conditions of thetest and has the same value for the reinforcement or matrixalone as for the constituents in the composite.
26、4.1.1.1 Procedure A, for matrices such as epoxy resin, steel,copper, or others digestible by concentrated nitric acid.NOTE 1Many reinforcements are attacked by nitric acid. If reinforce-ment is attacked, an alternative method is recommended, depending on thematrix. See Annex A1.4.1.1.2 Procedure B,
27、for matrices such as epoxy, phenolic,polyamide, or thermoplastic resin, or others digestible by anaqueous mixture of sulfuric acid and hydrogen peroxide. SeeAnnex A2.4.1.1.3 Procedure C, for matrices such as epoxy resin andothers digestible by a mixture of ethylene glycol and potassiumhydroxide. See
28、 Annex A3.NOTE 2Procedure C is especially applicable to anhydride-curedepoxy systems containing aramid or carbon reinforcement.4.1.1.4 Procedure D, for matrices such as aluminum, brass,or others digestible by sodium hydroxide solution. See AnnexA4.4.1.1.5 Procedure E, for matrices such as steel, tit
29、anium,copper, aluminum, or others digestible by hydrochloric acid.See Annex A5.4.1.1.6 Procedure F, a version of Procedure A formicrowave-aided heating. See Annex A6.4.1.1.7 Procedure G, for reinforcements such as glass, orceramic that are not affected by high-temperature environ-ments, or reinforce
30、ments such as carbon where temperature isadequately controlled so that reinforcement does not char. SeeAnnex A7.4.2 Test Method IIThe thickness of a relatively flat panelmade with reinforcement of known and consistent areal weightis measured. By the thickness of the panel, the reinforcementand matri
31、x content is calculated.5. Significance and Use5.1 A constituent content of a composite material must beknown in order to analytically model the material properties(mechanical, physical, thermal, or electrical) of the compositewhich are affected by the reinforcement or matrix. Also,knowledge of the
32、constituent content is required for evaluationof the quality of a fabricated material and the processes usedduring fabrication.5.2 The void volume of a composite material may signifi-cantly affect some of its mechanical properties. Higher voidvolumes usually mean lower fatigue resistance, greater su
33、scep-tibility to moisture penetration and weathering, and increasedvariation or scatter in strength properties. Knowledge of thevoid volume of a composite material is desirable as anindication of the quality of a composite.5.3 Reinforcement content may be used to normalize me-chanical properties aff
34、ected by amount of reinforcement in thecoupon.6. Interferences6.1 Density of ConstituentsCalculation of the void vol-ume assumes that reinforcement density and matrix densityobtained on a lot or material basis are held in the laminatesample. There is a normal variation in reinforcement andD3171062ma
35、trix densities that is dependent on the constituent material.This assumption used by the void calculation equations istypically minor, changing the void calculation by less than0.2 %. One indication of this variation is the possibility ofobtaining a negative void volume in low-void volume compos-ite
36、s. If procedural errors can be ruled out, then it is reasonableto believe that constituent density variation is responsible.Negative void content is a physical impossibility, but apossibility in these calculations. It is useful to report negativevoid contents to assess if constituent density values
37、areincorrect or within a typical range of material variation. Thenegative void value then sets an upper bound on error of thistest method for any material.6.2 Coupon SizeAbility to estimate void content is alsodetermined by coupon size and limitations of measuringapparatus. For example, with just li
38、mitations of the analyticalbalance (accurate to 0.2 mg), a coupon of 0.2 g with a voidvolume of 1.0 % would have an uncertainty of 10 % (reportedvoid volume in the range of 0.9 to 1.1 %) on the void volumecalculation as a result of possible balance error. A 1-g samplewould have an uncertainty of 2 %
39、 in the void volume calcula-tion (reported void volume in the range of 0.98 to 1.02 %)because of possible balance error for the same 1.0 % voidvolume.6.3 Error in Previous Measures4,5Ability to estimate voidcontent is also determined by the accuracy of previous mea-sures. Density measures of constit
40、uents and laminate havesome limitations. Good measures of these properties shouldhave an uncertainty of less than 0.0005 g/mL. For a typicalcarbon/epoxy laminate, uncertainty in the void volume becauseof the limitation of the constituent density measurement wouldbe approximately 1 %.6.4 Mass Change
41、of ReinforcementFibers may lose massby any of the techniques in Test Method I. This may beinvestigated by subjecting the reinforcement without matrix tothe test conditions of the composite. Once the technique isestablished for a material, no significant changes are expectedbetween samples unless the
42、 product or test conditions varysignificantly.6.5 Residual Matrix RetainedMatrix may be retained byany of the techniques of Test Method I. This may be investi-gated quantitatively by subjecting the matrix to the testconditions of the composite. Qualitatively, matrix appears ashardened pieces in the
43、sample at the end of the test. Once thetechnique is established for a material, no significant changesare expected between samples unless the product or testconditions vary significantly.6.6 Micrometer InterfaceThe thickness of the laminatecontinuously changes, particularly for surfaces with a relea
44、secloth or irregular surface. Test Method II measures the laminateat certain areas. The micrometer gives an indication of thethickness of the material at a point. The micrometer thicknessmeasure is dependent on (1) variation in thickness of the panel,(2) type and diameter of thickness measuring devi
45、ce, (3) abilityto hold panel perpendicular to the measurement device, and (4)sensitivity of the measurement device.6.6.1 Ball micrometer geometry tends to give a thicknessmeasure for Test Method II that more closely approximatesfiber volume if there is a rough surface texture than a flat-facedmicrom
46、eter that tends to overstate laminate thickness. Forsome material forms, such as open weaves, the ball geometryis not practical, so that a flat face micrometer is recommended.7. Apparatus7.1 General Requirements:7.1.1 Thermal ShockLaboratory equipment, which is sub-jected to nonambient temperatures
47、(hot or cold), shall be oftempered glass or polytetrafluoroethylene (PTFE) materials.7.1.2 Post-Test Elemental AnalysisIf a post-test elementalanalysis of the reinforcement residue is to be performed,laboratory equipment contacting the specimen shall be con-structed of PTFE, and specimen cutting per
48、formed only bydiamond-tipped tools.7.2 General Usage:7.2.1 Analytical BalanceThe analytical balance shall becapable of reading to within 60.1 mg.7.2.2 Laboratory Desiccator.7.3 Test Method I:7.3.1 Heating Equipment:7.3.1.1 Constant Heat SourceHeating mantle, hot plate,or controlled temperature bath,
49、 capable of heating material tothe required temperature for the particular digestion mediumand shall be capable of maintaining the temperature to 610C.7.3.1.2 Microwave, capable of maintaining a constant poweroutput. The microwave setup shall include an overpressurefail-safe device. Used exclusively for Procedure F (see AnnexA6).7.3.1.3 Drying Oven, air circulating, capable of maintaininga temperature of 100 6 3C or other target temperature within63C.7.3.1.4 Muffle Furnace, capable of maintaining a tempera-ture where the polymer matrix is removed, but th
