1、Designation: E2092 09E2092 13Standard 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 revisio
2、n, the 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. Scope1.1 This test method describes the determination of the temperature at which the specific modulus of a test
3、 specimen is realizedby deflection in three-point bending. This temperature is identified as the distortion temperature measured. temperature. Thedistortion temperature is that temperature at which a test specimen of defined geometry deforms to a level of strain under appliedstress of 0.455 MPa (66
4、psi) (Method A) and 1.82 MPa (264 psi) (Method B) (66 and 264 psi) equivalent to those used in TestMethod D648. The test may be performed over the range of temperature from ambient to 300C.NOTE 1This test method is intended to provide results similar to those of Test Method D648 but are performed on
5、 a thermomechanical analyzer usinga smaller test specimen. Equivalence of results to those obtained by Test Method D648 has been demonstrated on a limited number of materials. Untilthe user demonstrates equivalence, the The results of this test method shall be considered to be independent and unrela
6、ted to those of Test Method D648.unless the user demonstrates equivalence.1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.3 This standard does not purport to address all of the safety problems, if any, associated with it
7、s use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and to determine the applicability of regulatorylimitations prior to use.1.4 There is no ISO standard equivalent to this test method.2. Referenced Documents2.1 ASTM Standards:2D648 Test M
8、ethod for Deflection Temperature of Plastics Under Flexural Load in the Edgewise PositionE473 Terminology Relating to Thermal Analysis and RheologyE1142 Terminology Relating to Thermophysical PropertiesE1363 Test Method for Temperature Calibration of Thermomechanical AnalyzersE2113 Test Method for L
9、ength Change Calibration of Thermomechanical AnalyzersE2206 Test Method for Force Calibration of Thermomechanical Analyzers3. Terminology3.1 Definitions:Definitions3.1.1 Specific technical terms used in this standard are defined in Terminologies E473 and E1142 include thermomechanicalanalyzer.Specif
10、ic technical terms used in this standard are defined in Terminologies E473 and E1142, including thermome-chanical analyzer.3.1.1 distortion temperature C, nthe temperature at which an arbitrary strain level is obtained in three-point bending underan arbitrary load.3.1.2 strain, r mm/m, nthe dimensio
11、n change in normalizing dimension due to an applied force.3.1.3 stress, S Pa = N/m2, nforce per unit area.1 This test method is under the jurisdiction of Committee E37 on Thermal Measurements and is the direct responsibility of Subcommittee E37.10 on Fundamental,Statistical and Mechanical Properties
12、.Current edition approved Sept. 1, 2009Sept. 1, 2013. Published October 2009October 2013. Originally approved in 2000. Last previous edition approved in 20042009 asE2092 04.E2092 09. DOI: 10.1520/E2092-09.10.1520/E2092-13.2 For referenced ASTM standards, visit the ASTM website, www.astm.org, or cont
13、act ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandardsvolume information, refer tot he standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have bee
14、n made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document
15、.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14. Summary of Test Method4.1 A test specimen of known dimensions is tested in three-point bending mode. A known stress is applied to the center of atest specimen supported near its ends
16、, as it is heated at a constant rate from ambient temperature to the upper temperature limitfor the material. The deflection of the test specimen is recorded as a function of temperature. The temperature at which apredetermined level of strain is observed in the test specimen is analyzed as the dist
17、ortion temperature.5. Significance and Use5.1 Data obtained by this test method shall not be used to predict the behavior of materials at elevated temperatures except inapplications in which the conditions of time, temperature, method of loading, and stress are similar to those specified in the test
18、.5.2 This standard is particularly suited for quality control and development work. The data are not intended for use in designor predicting endurance at elevated temperatures.6. Apparatus6.1 A thermomechanical analyzer consisting of:6.1.1 Rigid Specimen Holder, of inert, low expansivity material 20
19、 m m-1 C-1 to center the specimen in the furnace andto fix the specimen to mechanical ground.6.1.2 Flexure Fixture, of inert, low expansivity material 20 m m-1 C-1, to support the test specimen in a three-point bendingmode (see Fig. 1).6.1.3 Rigid Knife Edge Compression Probe, of inert, low expansiv
20、ity material 20 m m-1 C-1 that contacts the specimen withan applied compression force (see Fig. 1).6.1.4 Deflection Sensing Element, having a linear output over a minimum range of 5 mm to measure the displacement of therigid compression probe (see 6.1.3) to within 6 0.1 60.1 m.6.1.5 Programmable Wei
21、ght or Force Transducer, to generate a constant force (6 2.5 %) (62.5 %) between at least 0.01 to 1.0N, that is applied to the specimen through the rigid compression probe (see 6.1.3).6.1.6 Temperature Sensor, that can be positioned reproducibly in close proximity to the specimen to measure its temp
22、eraturewithin the range between 25 and 300C300 to 6 0.1C.6.1.7 Temperature Programmer and Furnace, capable of temperature programming the test specimen from ambient to 300Cat a linear rate of at least 2 6 0.1C/min.6.1.8 Means of Providing a Specimen Environment, of inert gas at a purge rate of 50 mL
23、/min 6 5 %.NOTE 2Typically, inert purge gases that inhibit specimen oxidation are 99.9+ % pure nitrogen, helium or argon. Dry gases are recommended for allFIG. 1 Flexure Support GeometryE2092 132experiments unless the effect of moisture is part of the study.6.1.9 Data Collection Device, to provide a
24、 means of acquiring, storing, and displaying measured or calculated signals, or both.The minimum output signals required for a thermomechanical analyzer are dimension ion change, temperature and time.6.1.10 While not required, it is convenient to have a data analysis device, that will perform and di
25、splay the calculations of thisstandard.6.2 Micrometer, calipers, film gage or other length-measuring device capable of measuring lengths of 0.01 to 20 mm with aprecision of 6 0.001 60.001 mm.7. Hazards7.1 Toxic or corrosive effluents, or both, may be released when heating some materials and could be
26、 harmful to personnel andto apparatus.7.2 Because the specimen size is small, care must be taken to ensure that each specimen is homogeneous and representative ofthe 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, or mo
27、lded shapes, or may be molded to the desired finished dimensions.8.2 The specimens used in this test method are ordinarily in the 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
28、 of the supportspan (L).NOTE 3Other specimen and support dimensions may be used but care must be taken that the support length to specimen thickness ratio (L/d) begreater than 10.NOTE 4The specimen shall be long enough to allow overhanging on each end of at least 10 % of the support span, that is, 1
29、 1.2 L.NOTE 5The overhang shall be sufficient to prevent the specimen from slipping 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 be reported relative to
30、 the specimen dimensions.8.4 Since duplicate determinations are required, at least 2 specimens shall be prepared from each sample.9. Calibration9.1 Calibrate the temperature display of the apparatus according to Test Method E1363 using a heating rate of 2 6 0.1C/min.9.2 Calibrate the deflection (len
31、gth change) display of the apparatus according to the instrument manufacturers instructions (seeTest Method E2113).9.3 Calibrate the mechanism for applying force to the test specimen according to the instrument manufacturers instructions (seeTest Method E2206).10. Procedure10.1 Measure the test leng
32、th (L) of the test specimen as the distance 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 test specimen to three significant figures (see Fig. 2).10.3 Select the stress (S) to be applied to
33、the test specimen. This value is typically 0.455 (Method A) or 1.82 MPa (Method B)(66 or 264 psi) 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 heat distortion temperature.NOTE 7This v
34、alue is typically 2.0 mm/m (0.20 %) to correspond with the values used in Test Method D648.10.5 Using Eq 1, calculate to three significant figures the force (F) to be applied to the test specimen to three significantfigures.specimen.10.6 Using Eq 3, calculate to three significant figures the deflect
35、ion (D) to be used as the experimental endpoint to threesignificant figures.endpoint.10.7 Center the specimen on the supports, with the long axis of the specimen perpendicular to the loading nose and supports(see Fig. 1).NOTE 8The typical rectangular test beam is tested flatwise on the support span,
36、 with the applied force through its thinnest dimension.E2092 13310.8 Set initial experimental conditions by placing the test specimen into flexure support, loading the compression probe ontothe center of the test specimen in the three-point bending mode with the force calculated in 10.5. Set the def
37、lection-axis signal tobe zero at ambient temperature.10.9 Program the temperature from ambient temperature at 2 6 0.1C/min until the deflection, D 6 10 %, determined in 10.6,is obtained while recording specimen deflection and temperature. Once the deflection value is achieved, terminate the temperat
38、ureprogram and remove the load from the test specimen. Cool the apparatus to ambient temperature.NOTE 9Should the approximate distortion temperature of the material be known, the temperature program might be started at an elevated temperaturethat shall be at least 50C below the anticipated distortio
39、n temperature.10.10 Perform a baseline determination similar to section 10.9 except that the test specimen is the inverted flexure fixture.NOTE 10This step measures the deflection of the rigid specimen holder, flexture fixture and rigid knife edge compression probe.10.11 For ease of interpretation,
40、display the thermal curves from sections 10.9 and 10.10 with deflection displayed on the Y-axisand 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 the baseline curve from 10.11 from the test speci
41、men curve from 10.9.10.13 The distortion temperature is taken as the temperature at which the test specimen achieves a distortion of the value of Dfrom the initial condition in the baseline subtracted curve of 10.12.10.14 Repeat the experiment on a second, different test specimen. Report the result
42、as the mean value of duplicatedeterminations.11. Calculation11.1 Calculate force value as follows:F 52S b d2!/3L! (1)where:F = force, N,S = stress, MPa,b = sample width, mm,d = sample thickness, mm, andL = length of the flexure fixture support span, mm.11.1.1 As an example, if:FIG. 2 Test Specimen G
43、eometryE2092 134S = 0.455 MPab = 2.7 mmd = 0.44 mmL = 5.08 mmthen:F5230.455 MPa32.7 mm30.44 mm30.44 mm!335.08 mm! 50.0312 N (2)11.2 Calculate deformation value as follows:D 5r L2!/6d! (3)where:r = strain, mm/m.11.2.1 As an example, if r = 2.0 mm/m, then:D52.0 mm/m35.08 mm35.08 mm!630.44 mm! 519.6 m
44、(4)12. Report12.1 Report the following information:12.1.1 Complete identification and description of the material tested including source, manufacturer code, and any thermal ormechanical pretreatment,12.1.2 Description of the instrument used, including model number and location of the temperature se
45、nsor,12.1.3 Details of the procedure used to calculate the heat distortion temperature including strain and the resultant force, stressand resultant strain, as well as specimen dimensions including flexure distance,12.1.4 Heating rate, C/min, and temperature range,12.1.5 A copy of all original recor
46、ds that are presented,12.1.6 The mean value of the distortion temperature in three-point bending, C, and12.1.7 The specific dated version of this test method used.FIG. 3 Thermal Curve for Poly(vinyl chloride)E2092 13513. Precision and Bias13.1 An interlaboratory test was conducted in 2003 to develop
47、 the precision and bias statement for this test method. Eightlaboratories, using apparatus from two manufacturers and two stress levels, characterized a poly(vinyl chloride) sample inquntuplicate. Six laboratories produced results at a stress level of 0.455 MPa (MethodA) and two laboratories at 1.82
48、 MPa (MethodB).313.2 Precision:13.2.1 Within laboratory variability may be described using the repeatability value (r) obtained by multiplying the repeatabilitystandard deviation by 2.8. The repeatability values estimates the 95 % confidence limit. That is, two results from the samelaboratory should
49、 be considered suspect (at the 95 % confidence level) if they differ by more than the repeatability value.13.2.1.1 The within laboratory repeatability standard deviation from results obtained at 0.455 MPa stress level (MethodA) wasfound to be 0.92 C 0.92C with 20 degrees of experimental freedom.13.2.1.2 The within laboratory repeatability standard deviation for results obtained at 1.82 MPa stress level (method(MethodB) was found to be 0.84 C 0.84C with 4 degrees of experimental freedom.NOTE 11Twenty degressdegre
