1、Designation: E 2092 04Standard Test Method forDistortion Temperature in Three-Point Bending byThermomechanical Analysis1This standard is issued under the fixed designation E 2092; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the
2、 year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method describes the determination of thetemperature at which the specific modulus of a test speci
3、men isrealized by deflection in three-point bending. This temperatureis identified as the distortion temperature measured. Thedistortion temperature is that temperature at which a testspecimen of defined geometry deforms to a level of strainunder applied stress of 0.455 (Method A) and 1.82 MPa(Metho
4、d B) (66 and 264 psi) equivalent to those used in TestMethod D 648. The test may be performed over the range oftemperature from ambient to 300C.NOTE 1This test method is intended to provide results similar to thoseof Test Method D 648 but are performed on a thermomechanical analyzerusing a smaller t
5、est specimen. Equivalence of results to those obtained byTest Method D 648 has been demonstrated on a limited number ofmaterials. Until the user demonstrates equivalence, the results of this testmethod shall be considered to be independent and unrelated to those ofTest Method D 648.1.2 Electronic in
6、strumentation or automated data analysisand reduction systems or treatments equivalent to this testmethod may be used.NOTE 2Since all electronic data treatments are not equivalent, theuser shall verify equivalency to this test method.1.3 SI values are the standard.1.4 This standard does not purport
7、to address all of thesafety problems, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and to determine theapplicability of regulatory limitations prior to use.1.5 There is no ISO standard equivalent to this t
8、est method.2. Referenced Documents2.1 ASTM Standards:2D 648 Test Method for Deflection Temperature of PlasticsUnder Flexural LoadE 473 Terminology Relating to Thermal AnalysisE 1142 Terminology Relating to Thermophysical PropertiesE 1363 Test Method for Temperature Calibration of Ther-momechanical A
9、nalyzers3. Terminology3.1 DefinitionsSpecific technical terms used in this stan-dard are defined in Terminologies E 473 and E 1142.3.1.1 distortion temperature C, nthe temperature atwhich an arbitrary strain level is obtained in three-pointbending under an arbitrary load.3.1.2 strain, r mm/m, nthe d
10、imension change in normal-izing dimension due to an applied force.3.1.3 stress, S Pa = N/m2, nforce per unit area.4. Summary of Test Method4.1 A test specimen of known dimensions is tested inthree-point bending mode. A known stress is applied to thecenter of a test specimen supported near its ends,
11、as it is heatedat a constant rate from ambient temperature to the uppertemperature limit for the material. The deflection of the testspecimen is recorded as a function of temperature. Thetemperature at which a predetermined level of strain is ob-served in the test specimen is analyzed as the distort
12、iontemperature.5. Significance and Use5.1 Data obtained by this test method shall not be used topredict the behavior of materials at elevated temperaturesexcept in applications in which the conditions of time, tem-perature, method of loading, and stress are similar to thosespecified in the test.5.2
13、This standard is particularly suited for quality controland development work. The data are not intended for use indesign or predicting endurance at elevated temperatures.6. Apparatus6.1 A thermomechanical analyzer consisting of:1This test method is under the jurisdiction of Committee E37 on ThermalM
14、easurements and is the direct responsibility of Subcommittee E37.01 on TestMethods and Recommended Practices.Current edition approved March 1, 2004. Published April 2004. Originallyapproved in 2000. Last previous edition approved in 2003 as E209203.2For referenced ASTM standards, visit the ASTM webs
15、ite, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandardsvolume information, refer tot he standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United State
16、s.6.1.1 Rigid Specimen Holder, of inert, low expansivitymaterial 20 m m-1C-1to center the specimen in the furnaceand to fix the specimen to mechanical ground.6.1.2 Flexure Fixture, of inert, low expansivity material 20m m-1C-1, to support the test specimen in a three-pointbending mode (see Fig. 1).6
17、.1.3 Rigid Knife Edge Compression Probe, of inert, lowexpansivity material 20 m m-1C-1that contacts thespecimen with an applied compression force (see Fig. 1).6.1.4 Deflection Sensing Element, having a linear outputover a minimum range of 5 mm to measure the displacement ofthe rigid compression prob
18、e (see 6.1.3) to within 6 0.1 m.6.1.5 Programmable Weight or Force Transducer, to gener-ate a constant force (6 2.5 %) between at least 0.01 to 1.0 N,that is applied to the specimen through the rigid compressionprobe (see 6.1.3).6.1.6 Temperature Sensor, that can be positioned reproduc-ibly in close
19、 proximity to the specimen to measure its tempera-ture within the range between 25 and 300C to 6 0.1C.6.1.7 Temperature Programmer and Furnace, capable oftemperature programming the test specimen from ambient to300C at a linear rate of at least 2 6 0.1C/min.6.1.8 Means of Providing a Specimen Enviro
20、nment, of inertgas at a purge rate of 50 mL/min 6 5%.NOTE 3Typically, inert purge gases that inhibit specimen oxidationare 99.9+ % pure nitrogen, helium or argon. Dry gases are recommendedfor all experiments unless the effect of moisture is part of the study.6.1.9 Recording Device, to record and dis
21、play the experi-mental parameters of deflection on the Y axis (ordinate) to asensitivity of 6 0.1 m and of temperature on the X axis(abscissa) to a sensitivity of 6 0.1C.6.1.10 While not required, it is convenient to have a dataanalysis device, that will perform and display the calculationsof this s
22、tandard.6.2 Micrometer, calipers, film gage or other length-measuring device capable of measuring lengths of 0.01 to 20mm with a precision of 6 0.001 mm.7. Hazards7.1 Toxic or corrosive effluents, or both, may be releasedwhen heating some materials and could be harmful to person-nel and to apparatus
23、.7.2 Because the specimen size is small, care must be takento ensure that each specimen is homogeneous and representa-tive of the sample as a whole.7.3 The test specimen shall be isotropic. See 8.3.8. Sampling8.1 The specimens may be cut from sheets, plates, ormolded shapes, or may be molded to the
24、desired finisheddimensions.8.2 The specimens used in this test method are ordinarily inthe form of rectangular beams with aspect ratios of 1: 3: 10 forthickness or specimen depth (d), width (b) and length (l),depending upon the modulus of the sample and length of thesupport span (L).NOTE 4Other spec
25、imen and support dimensions may be used but caremust be taken that the support length to specimen thickness ratio (L/d)begreater than 10.NOTE 5The specimen shall be long enough to allow overhanging oneach end of at least 10 % of the support span, that is, 1 $ 1.2 L.NOTE 6The overhang shall be suffic
26、ient to prevent the specimen fromslipping from the supports.8.3 This test method assumes that the material is isotropic.Should the specimen be anisotropic, such as in reinforcedcomposites, the direction of the reinforcing agent shall bereported relative to the specimen dimensions.8.4 Since duplicate
27、 determinations are required, at least 2specimens shall be prepared from each sample.9. Calibration9.1 Calibrate the temperature display of the apparatus ac-cording to Test Method E 1363 using a heating rate of 2 60.1C/min.9.2 Calibrate the deflection display of the apparatus accord-ing to the instr
28、ument manufacturers instructions.9.3 Calibrate the mechanism for applying force to the testspecimen according to the instrument manufacturers instruc-tions.10. Procedure10.1 Measure the test length (L) of the test specimen as thedistance between the two support points of the flexure supportgeometry
29、to three significant figures (see Fig. 1).10.2 Measure the width (b) and thickness (d) of the testspecimen to three significant figures (see Fig. 2).10.3 Select the stress (S) to be applied to the test specimen.This value is typically 0.455 (Method A) or 1.82 MPa MPa(Method B) (66 or 264 psi) to cor
30、respond with the values usedin Test Method D 648.FIG. 1 Flexure Support GeometryE2092042NOTE 7Other values may be used but shall be reported.10.4 Select the strain (r) to be used to identify the heatdistortion temperature.NOTE 8This value is typically 2.0 mm/m (0.20 %) to correspond withthe values u
31、sed in Test Method D 648.10.5 Using Eq 1, calculate the force (F) to be applied to thetest specimen to three significant figures.10.6 Using Eq 3, calculate the deflection (D) to be used asthe experimental endpoint to three significant figures.10.7 Center the specimen on the supports, with the long a
32、xisof the specimen perpendicular to the loading nose and supports(see Fig. 1).NOTE 9The typical rectangular test beam is tested flatwise on thesupport span, with the applied force through its thinnest dimension.10.8 Set initial experimental conditions by placing the testspecimen into flexure support
33、, loading the compression probeonto the center of the test specimen in the three-point bendingmode with the force calculated in 10.5. Set the deflection-axissignal to be zero at ambient temperature.10.9 Program the temperature from ambient temperature at2 6 0.1C/min until the deflection, D 6 10 %, d
34、etermined in10.6, is obtained while recording specimen deflection andtemperature. Once the deflection value is achieved, terminatethe temperature program and remove the load from the testspecimen. Cool the apparatus to ambient temperature.NOTE 10Should the approximate distortion temperature of the m
35、ate-rial be known, the temperature program might be started at an elevatedtemperature that shall be at least 50C below the anticipated distortiontemperature.10.10 Perform a baseline determination similar to section10.9 except that the test specimen is the inverted flexurefixture.NOTE 11This step mea
36、sures the deflection of the rigid specimenholder, flexture fixture and rigid knife edge compression probe.10.11 For ease of interpretation, display the thermal curvesfrom sections 10.9 and 13.1 with deflection displayed on theY-axis and temperature on the X-axis as illustrated in Fig. 3,both axes se
37、t to the same scale sensitivity.10.12 Using the same Y-axis scale sensitivity, subtract thebaseline curve from 13.1 from the test specimen curve from10.9.10.13 The distortion temperature is taken as the temperatureat which the test specimen achieves a distortion of the value ofD from the initial con
38、dition in the baseline subtracted curve of10.12.10.14 Repeat the experiment on a second, different testspecimen. Report the result as the mean value of duplicatedeterminations.11. Calculation11.1 Calculate force value as follows:F 5 2 Sbd2!/3 L! (1)where:F = force, N,S = stress, MPa,b = sample width
39、, mm,d = sample thickness, mm, andL = length of the flexure fixture support span, mm.11.1.1 As an example, if:S = 0.455 MPab = 2.7 mmd = 0.44 mmL = 5.08 mmthen:FIG. 2 Test Specimen GeometryE2092043F 52 3 0.455 MPa 3 2.7 mm 3 0.44 mm 3 0.44 mm!3 3 5.08 mm!5 0.0312 N(2)11.2 Calculate deformation value
40、 as follows:D 5 rL2!/6 d! (3)where:r = strain, mm/m.11.2.1 As an example, if r = 2.0 mm/m, then:D 52.0 mm/m 3 5.08 mm 3 5.08 mm!6 3 0.44 mm!5 19.6 m (4)12. Report12.1 Report the following information:12.1.1 Complete identification and description of the mate-rial tested including source, manufacture
41、r code, and anythermal or mechanical pretreatment,12.1.2 Description of the instrument used, including modelnumber and location of the temperature sensor,12.1.3 Details of the procedure used to calculate the heatdistortion temperature including strain and the resultant force,stress and resultant str
42、ain, as well as specimen dimensionsincluding flexure distance,12.1.4 Heating rate, C/min, and temperature range,12.1.5 A copy of all original records that are presented,12.1.6 The mean value of the distortion temperature inthree-point bending, C, and12.1.7 The specific dated version of this test met
43、hod used.13. Precision and Bias13.1 An interlaboratory test was conducted in 2003 todevelop the precision and bias statement for this method. Eightlaboratories, using apparatus from two manufacturers and twostress levels, characterized a poly(vinyl chloride) sample inquntuplicate. Six laboratories p
44、roduced results at a stress levelof 0.455 MPa (Method A) and two laboratories at 1.82 MPa(Method B).313.2 Precision:13.2.1 Within laboratory variability may be described usingthe repeatability value (r) obtained by multiplying the repeat-ability standard deviation by 2.8. The repeatability valuesest
45、imates the 95 % confidence limit. That is, two results fromthe same laboratory should be considered suspect (at the 95 %confidence level) if they differ by more than the repeatabilityvalue.13.2.1.1 The within laboratory repeatability standard devia-tion from results obtained at 0.455 MPa stress leve
46、l (MethodA) was found to be 0.92 C with 20 degrees of experimentalfreedom.13.2.1.2 The within laboratory repeatability standard devia-tion for results obtained at 1.82 MPa stress level (method B)was found to be 0.84 C with 4 degrees of experimentalfreedom.NOTE 12Twenty degress of freedom is the mini
47、mum acceptable for asound interlaboratory test. Insufficient laboratories were available toprovide results at the 1.82 MPA stress level. Thus the informationprovided here for this load level is for informational purposes only.13.2.2 A Between laboratory variability may be describeusing the reproduci
48、bility value (R) obtained by multiplying thereproducibility standard deviation by 2.8. The reproducibilityvalue estimates the 95 % confidence limit. That is, results3A Research Report is available from ASTM. Request RR:E371032.FIG. 3 Thermal Curve for Poly(vinyl chloride)E2092044obtained in two diff
49、erent laboratories should be consideredsuspect (at the 95 % confidence level) if they differ by morethat the reproducibility value.13.2.2.1 The between laboratory reproducibility standarddeviation for results obtained at 0.455 MPa stress (Method A)was found to be 3.9 C.13.2.2.2 The between laboratory range for results obtainedat 1.82 MPa (Method B) was found to be 3.9 C for resultsform 2 laboratories (see Note 11).13.3 Bias:13.3.1 Bias is the difference between the mean value ob-tained and an an accepted reference value for
