ASTM E2092-2018a Standard Test Method for Distortion Temperature in Three-Point Bending by Thermomechanical Analysis.pdf

1、Designation: E2092 18aStandard Test Method forDistortion Temperature in Three-Point Bending byThermomechanical Analysis1This standard is issued under the fixed designation E2092; 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 () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method describes the determination of thetemperature at which the specific modulus of a test specim

3、en isrealized by deflection in three-point bending. This temperatureis identified as the distortion temperature. The distortiontemperature is that temperature at which a test specimen ofdefined geometry deforms to a level of strain under appliedstress of 0.455 MPa (66 psi) (Method A) and 1.82 MPa (2

4、64psi) (Method B) equivalent to those used in Test Method D648.The test is applicable over the range of temperature fromambient to 300 C.NOTE 1This test method is intended to provide results similar to thoseof Test Method D648 but is performed on a thermomechanical analyzerusing a smaller test speci

5、men. Equivalence of results to those obtained byTest Method D648 has been demonstrated on a limited number ofmaterials. The results of this test method shall be considered to beindependent and unrelated to those of Test Method D648 unless the userdemonstrates equivalence.1.2 The values stated in SI

6、units are to be regarded asstandard. No other units of measurement are included in thisstandard.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, health, and

7、 environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International S

8、tandards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D648 Test Method for Deflection Temperature of PlasticsUnder Flexural Load in the Edgewise PositionE473 Terminology Relating to Thermal A

9、nalysis and Rhe-ologyE1142 Terminology Relating to Thermophysical PropertiesE1363 Test Method for Temperature Calibration of Thermo-mechanical AnalyzersE2113 Test Method for Length Change Calibration of Ther-momechanical AnalyzersE2206 Test Method for Force Calibration of Thermome-chanical Analyzers

10、3. Terminology3.1 DefinitionsSpecific technical terms used in this stan-dard are defined in Terminologies E473 and E1142, includingstress, strain, and thermomechanical analyzer.3.1.1 distortion temperature C, nthe temperature atwhich an arbitrary strain level is obtained in three-pointbending under

11、an arbitrary load.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, as it is heatedat a constant rate from ambient temperature to the uppertemperature limit for the

12、 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 distortiontemperature.1This test method is under the jurisdiction of Committee E37 on ThermalMeasuremen

13、ts and is the direct responsibility of Subcommittee E37.10 onFundamental, Statistical and Mechanical Properties.Current edition approved Dec. 1, 2018. Published January 2019. Originallyapproved in 2000. Last previous edition approved in 2018 as E2092 18. DOI:10.1520/E2092-18A.2For referenced ASTM st

14、andards, visit the ASTM website, 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.*A Summary of Changes section appears at the end of this standardCopyright ASTM Inter

15、national, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,

16、Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.15. 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

17、time,temperature, method of loading, and stress are similar to thosespecified in the test.5.2 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 a

18、nalyzer consisting of:6.1.1 Rigid Specimen Holder, of inert, low coefficient ofexpansion material 20 m m-1C-1to center the specimen inthe furnace and to fix the specimen to mechanical ground.6.1.2 Flexure Fixture, of inert, low coefficient of expansionmaterial 20 m m-1C-1, to support the test specim

19、en in athree-point bending mode (see Fig. 1).6.1.3 Rigid Knife Edge Compression Probe, of inert, lowcoefficient of expansion material 20 m m-1C-1thatcontacts the specimen with an applied compression force (seeFig. 1).6.1.4 Deflection Sensing Element, having a linear outputover a minimum range of 5 m

20、m to measure the displacement ofthe rigid compression probe (see 6.1.3) to within 60.1 m.6.1.5 Programmable Weight or Force Transducer, to gener-ate a constant force (62.5 %) between at least 0.01 N to 1.0 N,that is applied to the specimen through the rigid compressionprobe (see 6.1.3).6.1.6 Tempera

21、ture Sensor, that can be positioned reproduc-ibly in close proximity to the specimen to measure its tempera-ture within the range between 25 C and 300 C readable to 60.1 C.6.1.7 Temperature Programmer and Furnace, capable oftemperature programming the test specimen from ambient to300 C at a linear r

22、ate of at least 2 6 0.1 C/min.6.1.8 Means of Providing a Specimen Environment, of inertgas at a purge rate of 50 mL/min 6 5%.NOTE 2Typically, inert purge gases that inhibit specimen oxidationare 99.9+ % pure nitrogen, helium or argon. Dry gases are recommendedfor all experiments unless the effect of

23、 moisture is part of the study. Thepurge gas used for the test specimen shall be the same as that used duringcalibration.6.1.9 Data Collection Device, to provide a means ofacquiring, storing, and displaying measured or calculatedsignals, or both. The minimum output signals required for athermomechan

24、ical analyzer are dimension ion change, tem-perature and time.6.1.10 While not required, it is convenient to have a dataanalysis device, that will perform and display the calculationsof this standard.6.2 Micrometer, calipers, film gage or other length-measuring device capable of measuring lengths of

25、 0.01 mm to20 mm readable to within 60.001 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.7.2 Because the specimen size is small, care must be takento ensure that each specimen is homogeneous and

26、representa-tive of the sample as a whole.8. Sampling8.1 The specimens may be cut from sheets, plates, ormolded shapes, or may be molded to the 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 forthickn

27、ess or specimen depth (d), width (b) and length (l),depending upon the modulus of the sample and length of thesupport span (L).NOTE 3Other specimen and support dimensions may be used but caremust be taken that the support length to specimen thickness ratio (L/d)begreater than 10.NOTE 4The specimen s

28、hall be long enough to allow overhanging oneach end of at least 10 % of the support span, that is, l 1.2 L.NOTE 5The overhang shall be sufficient to prevent the specimen fromslipping from the supports.8.3 This test method assumes that the material is isotropic.Should the specimen be anisotropic, suc

29、h as in reinforcedcomposites, the direction of the reinforcing agent shall bereported relative to the specimen dimensions.9. Calibration9.1 Calibrate the temperature display of the apparatus ac-cording to Test Method E1363 using a heating rate of 2 C/min6 0.1 C/min.FIG. 1 Flexure Support GeometryE20

30、92 18a29.2 Calibrate the deflection (length change) display of theapparatus according to the instrument manufacturers instruc-tions (see Test Method E2113).9.3 Calibrate the mechanism for applying force to the testspecimen according to the instrument manufacturers instruc-tions (see Test Method E220

31、6).10. Procedure10.1 Measure the test length (L) of the test specimen as thedistance between the two support points of the flexure supportgeometry 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

32、 Select the stress (S) to be applied to the test specimen.This value is typically 0.455 (Method A) or 1.82 MPa (MethodB) to correspond with the values used in Test Method D648.NOTE 6Other values may be used but shall be reported.10.4 Select the strain (r) to be used to identify the heatdistortion te

33、mperature.NOTE 7This value is typically 2.0 mm/m (0.20 %) to correspond withthe values used in Test Method D648.10.5 Using Eq 1, calculate to three significant figures theforce (F) to be applied to the test specimen.10.6 Using Eq 3, calculate to three significant figures thedeflection (D) to be used

34、 as the experimental endpoint.10.7 Center the specimen on the supports, with the long axisof the specimen perpendicular to the loading nose and supports(see Fig. 1).NOTE 8The typical rectangular test beam is tested flatwise on thesupport span, with the applied force through its thinnest dimension.10

35、8 Set initial experimental conditions by placing the testspecimen into flexure support, 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 th

36、e temperature from ambient temperature at2 C/min 6 0.1 C/min until the deflection, D 6 10 %,determined in 10.6, is obtained while recording specimendeflection and temperature. Once the deflection value isachieved, terminate the temperature program and remove theload from the test specimen. Cool the

37、apparatus to ambienttemperature.NOTE 9Should the approximate distortion temperature of the materialbe known, the temperature program might be started at an elevatedtemperature that shall be at least 50 C below the anticipated distortiontemperature.10.10 Perform a baseline determination similar to se

38、ction10.9 except that the test specimen is the inverted flexurefixture.NOTE 10This step measures the deflection of the rigid specimenholder, flexure fixture and rigid knife edge compression probe.10.11 For ease of interpretation, display the thermal curvesfrom sections 10.9 and 10.10 with deflection

39、 displayed on theY-axis and temperature on the X-axis as illustrated in Fig. 3,both axes set to the same scale sensitivity.10.12 Using the same Y-axis scale sensitivity, subtract thebaseline curve from 10.11 from the test specimen curve from10.9.FIG. 2 Test Specimen GeometryE2092 18a310.13 The disto

40、rtion temperature is taken as the temperatureat which the test specimen achieves a distortion of the value ofD from the initial condition in the baseline subtracted curve of10.12.11. Calculation11.1 Calculate force value as follows:F 5 2 Sbd2!/3 L! (1)where:F = force, N,S = stress, MPa,b = sample wi

41、dth, mm,d = sample thickness, mm, andL = length of the flexure fixture support span, mm.11.1.1 As an example, if:S = 0.455 MPa,b = 2.7 mm,d = 0.44 mm, andL = 5.08 mm.then:F 52 30.455 MPa 32.7 mm 30.44 mm 30.44 mm!3 35.08 mm!5 0.0312 N(2)11.2 Calculate deformation value as follows:D 5 rL2!/6 d! (3)wh

42、ere:r = strain, mm/m.11.2.1 As an example, if:r = 2.0 mm/m.then:D 52.0 mm/m 35.08 mm 35.08 mm!6 30.44 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, manufacturer code, and anythermal or mechanica

43、l 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 strain, as well as specimen dimensions

44、including 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 value of the distortion temperature in three-pointbending, C, and12.1.7 The specific dated version of this test method used.13. Precision and Bias13.1 An i

45、nterlaboratory test was conducted in 2003 todevelop the precision and bias statement for this test method.Eight laboratories, using apparatus from two manufacturersand two stress levels, characterized a poly(vinyl chloride)sample in quintuplicate. Six laboratories produced results at aFIG. 3 Thermal

46、 Curve for Poly(vinyl chloride)E2092 18a4stress level of 0.455 MPa (Method A) and two laboratories at1.82 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 re

47、peatability valuesestimates 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

48、0.455 MPa stress level (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 11Twenty degrees o

49、f freedom is the minimum acceptable for asound interlaboratory test. Insufficient laboratories were available toprovide results at the 1.82 MPa stress level. Thus the information providedhere for this load level is for informational purposes only.13.2.2 Between laboratory variability may be describedusing the reproducibility value (R) obtained by multiplying thereproducibility standard deviation by 2.8. The reproducibilityvalue estimates the 95 % confidence limit. That is, resultsobtained in two different laboratories should