1、Designation: D 1822 06Standard Test Method forTensile-Impact Energy to Break Plastics and ElectricalInsulating Materials1This standard is issued under the fixed designation D 1822; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, th
2、e 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. Scope*1.1 This test method covers the determination of the energyrequired to rupture standard tension-impact specime
3、ns ofplastic or electrical insulating materials. Materials that can betested by this test method are those too flexible or too thin tobe tested in accordance with Test Methods D 256, as well asmore rigid materials.1.2 The values stated in SI units are to be regarded asstandard. The values given in b
4、rackets are for information only.NOTE 1This test method is not equivalent to ISO 8256, and resultscannot be directly compared between the two methods.1.3 This standard does not purport to address all of thesafety problems, if any, associated with its use. It is theresponsibility of the user of this
5、standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 256 Test Methods for Determining the Izod PendulumImpact Resistance of PlasticsD 618 Practice for Conditioning Plastics
6、for TestingD 638 Test Method for Tensile Properties of PlasticsD 883 Terminology Relating to PlasticsD 1822 Test Method for Tensile-Impact Energy to BreakPlastics and Electrical Insulating MaterialsD 1898 Practice for Sampling of Plastics3D 4000 Classification System for Specifying Plastic Mate-rial
7、sD 4066 Classification System for Nylon Injection and Ex-trusion Materials (PA)E23 Test Methods for Notched Bar Impact Testing ofMetallic Materials3. Terminology3.1 DefinitionsDefinitions of terms applying to this testmethod appear in Terminology D 883.4. Summary of Test Method4.1 The energy utilize
8、d in this test method is delivered by asingle swing of a calibrated pendulum of a standardizedtension-impact machine. The energy to fracture by shock intension is determined by the kinetic energy extracted from thependulum of an impact machine in the process of breaking thespecimen. One end of the s
9、pecimen is mounted in the pendu-lum. The other end of the specimen is gripped by a crossheadwhich travels with the pendulum until the instant of impact andinstant of maximum pendulum kinetic energy, when thecrosshead is arrested.5. Significance and Use5.1 Tensile-impact energy is the energy required
10、 to break astandard tension-impact specimen in tension by a single swingof a standard calibrated pendulum under a set of standardconditions (Note 2). In order to compensate for the minordifferences in cross-sectional area of the specimens as they willoccur in the preparation of the specimens, the en
11、ergy to breakcan be normalized to units of kilojoules per square metre (orfoot-pounds-force per square inch) of minimum cross-sectionalarea.An alternative approach to normalizing the impact energythat compensates for these minor differences and still retainsthe test unit as joules foot-pounds is sho
12、wn in Section 11. Fora perfectly elastic material the impact energy might be reportedper unit volume of material undergoing deformation. However,since much of the energy to break the plastic materials forwhich this test method is written is dissipated in drawing ofonly a portion of the test region,
13、such normalization on avolume basis is not feasible. The test method permits twospecimen geometries so that the effect of elongation or rate ofextension, or both, upon the result can be observed. With theType S (short) specimen the extension is comparatively low,while with the Type L (long) specimen
14、 the extension is1This test method is under the jurisdiction ofASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.10 on Mechanical Properties.Current edition approved March 15, 2006. Published March 2006. Originallyapproved in 1961. Last previous edition approved in 1
15、999 as D 1822 - 99.2For 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 page onthe ASTM website.3Withdrawn1*A Summary of Changes section a
16、ppears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United Sparatively high. In general, the Type S specimen (with itsgreater occurrence of brittle fracture) gives greater reproduc-ibility, but less differentiation am
17、ong materials. Results ob-tained with different capacity machines may not be compa-rable.NOTE 2Friction losses are largely eliminated by careful design andproper operation of the testing machine. Attention is drawn to TestMethods E23for a general discussion of impact equipment and proce-dures.5.2 Th
18、e scatter of data may be due to different failuremechanisms within a group of specimens. Some materials mayexhibit a transition between different failure mechanisms; if so,the elongation will be critically dependent on the rate ofextension encountered in the test. The impact energy values fora group
19、 of such specimens will have an abnormally largedispersion. Some materials retract at failure with insignificantpermanent set. With such materials it may not be possible todetermine the type of failure, ductile, or brittle, by examiningthe broken pieces.Aset of specimens may sometimes be sortedinto
20、two groups by observing the broken pieces to ascertainwhether or not there was necking during the test. Qualitatively,the strain rates encountered here are intermediate between thehigh rate of the Izod test of Test Methods D 256 and the lowrate of usual tension testing in accordance with Test Method
21、D 638.5.3 The energy for fracture is a function of the force timesthe distance through which the force operates. Thus, twomaterials may have properties that result in equal tensile-impact energies on the same specimen geometry, arising in onecase from a large force associated with a small elongation
22、 andin the other from a small force associated with a largeelongation. It cannot be assumed that this test method willcorrelate with other tests or end uses unless such a correlationhas been established by experiment.5.4 Comparisons among specimens from different sourcescan be made with confidence o
23、nly to the extent that specimenpreparation, for example, molding history, has been preciselyduplicated. Comparisons between molded and machined speci-mens must not be made without first establishing quantitativelythe differences inherent between the two methods of prepara-tion.5.5 Only results from
24、specimens of nominally equal thick-ness and tab width shall be compared unless it has been shownthat the tensile-impact energy normalized to kilojoules persquare metre or foot-pounds-force per square inch of cross-sectional area is independent of the thickness over the range ofthicknesses under cons
25、ideration.5.6 Slippage of specimens results in erroneously high val-ues. The tabs of broken specimens should be examined for anundistorted image of the jaw faces optically, preferably undermagnification, and compared against a specimen which hasbeen similarly clamped but not tested. Because slippage
26、 hasbeen shown to be present in many cases and suspected inothers, the use of bolted specimens is mandatory. The functionFIG. 1 Specimen-in-Head Tension-Impact MachineD1822062of the bolt is to assure good alignment and to improve thetightening of the jaw face plates.5.7 The bounce of the crosshead s
27、upplies part of the energyto fracture test specimen (see Appendix X1).5.8 For many materials, there may be a specification thatrequires the use of this test method, but with some proceduralmodifications that take precedence when adhering to thespecification. Therefore, it is advisable to refer to th
28、at materialspecification before using this test method. Table 1 of Classi-fication System D 4000 lists theASTM materials standards thatcurrently exist.6. Apparatus6.1 The machine shall be of the pendulum type shownschematically in Fig. 1 and Fig. 2. The base and suspendingframe shall be of sufficien
29、tly rigid and massive construction toprevent or minimize energy losses to or through the base andframe. The pendulum should be released from such a positionthat the linear velocity of the center of impact (center ofpercussion) at the instant of impact shall be approximately3.444 m/s 11.3 ft/s, which
30、 corresponds to an initial elevationof this point of 610 mm 2.00 ft.6.2 The pendulum shall be constructed of a single- ormultiple-membered arm holding the head, in which the greatestmass is concentrated.Arigid pendulum is essential to maintainthe proper clearances and geometric relationships between
31、related parts and to minimize energy losses, which always areincluded in the measured impact energy value. It is imperativethat the center of percussion of the pendulum system and thepoint of impact can be demonstrated to be coincident within62.54 mm 60.100 in. and that the point of contact occur in
32、the neutral (free hanging) position of the pendulum within 2.54mm 0.100 in., both with and without the crosshead in place.NOTE 3The distance from the axis of support to the center ofpercussion may be determined experimentally from the period of smallamplitude oscillations of the pendulum by means of
33、 the followingequation:L 5 g/4p2! p2(1)where:L = distance from the axis of support to the center of percussion, mm(ft),g = local gravitational acceleration (known to an accuracy of one partin one thousand), in mm/s2ft/s2,p = 3.14159, andp = period, s, of a single complete swing (to and fro) determin
34、ed fromat least 50 consecutive and uninterrupted swings (known to onepart in two thousand). The angle of swing shall be less than 0.09radians (5) each side of the center.6.3 The positions of the rigid pendulum and crossheadclamps on the specimen are shown in Fig. 2. The crossheadshould be rigid and
35、light in weight. The crosshead shall besupported by the pendulum so that the test region of thespecimen is not under stress until the moment of impact, whenthe specimen shall be subjected to a pure tensile force. Theclamps shall have serrated jaws to prevent slipping. Jawsshould have file-like serra
36、tions and the size of serrations shouldbe selected according to experience with hard and toughmaterials and with the thickness of the specimen. The edge ofthe serrated jaws in close proximity to the test region shall havea 0.40-mm 164-in. radius to break the edge of the firstserrations.6.4 Means sha
37、ll be provided for determining the energyexpended by the pendulum in breaking the specimen. This isaccomplished using either a pointer and dial mechanism or anelectronic system consisting of a digital indicator and sensor(typically an encoder or resolver).6.5 The indicated breaking energy is determi
38、ned by detect-ing the height of rise of the pendulum beyond the point ofimpact in terms of energy removed from that specific pendu-lum.6.5.1 Since the indicated energy must be corrected forpendulum-bearing friction, pointer friction, pointer inertia, andpendulum windage, instructions for making thes
39、e correctionsare found in Test Method D 256. If the electronic display doesnot automatically correct for windage and friction, it shall beincumbent for the operator to determine the energy lossmanually.FIG. 2 Specimen-in-Head Tension-Impact Machine (Schematic)D18220636.5.2 Bounce correction is expla
40、ined in Appendix X1 ofTest Method D 1822. Some electronic displays permit the userto enter an energy correction offset so that the bounce correc-tion can be factored in before the breaking energy is displayed.6.6 Setup and calibration procedures for tension-impactmachines shall be followed as descri
41、bed in Appendix X2.6.7 A ball-type micrometer shall be used for measuring thewidth of the restricted area of the Type S specimen. Either aball-type or ordinary machinists micrometer may be used tomeasure the thickness of the Type S specimen and thethickness and width of the Type L specimen. These me
42、asure-ments shall be made to an accuracy of 0.013 mm 0.0005 in.7. Sampling7.1 Unless otherwise agreed upon between interested par-ties, the material shall be sampled in accordance with thesections on General Sampling Procedure in Practice D 1898.8. Test Specimen8.1 At least five and preferably ten s
43、pecimens from eachsample shall be prepared for testing. For sheet materials thatare suspected of anisotropy, duplicate sets of test specimensshall be prepared having their long axis respectively parallelwith, and normal to, the suspected directions of anisotropy.8.2 The test specimen shall be sanded
44、, machined, or die cutto the dimensions of one of the specimen geometries shown inFig. 3, or molded in a mold whose cavity has these dimensions.Fig. 4A shows bolt holes and bolt hole location and Fig. 4Bshows a slot as an alternative method of bolting for easyinsertion of the specimens into the grip
45、s. The No. 8-32 bolt sizeis recommended for the 9.53-mm 0.375-in. wide tab and No.8-32 or No. 10-32 bolt size is suggested for the 12.70-mm0.500-in. wide tabs. Final machined, cut, or molded specimendimensions cannot be precisely maintained because of shrink-age and other variables in sample prepara
46、tion.8.3 A nominal thickness of 3.2 mm 18 in. is optimum formost materials being considered and for commercially avail-able machines. Thicknesses other than 3.2 mm 18 in. arenonstandard and they should be reported with the tension-impact value.NOTE 4Cooperating laboratories should agree upon standar
47、d moldsand upon specimen preparation procedures and conditions.9. Conditioning9.1 ConditioningCondition the test specimens at 23 62C 73.4 6 3.6F and 50 6 5 % relative humidity for not lessthan 40 h prior to test in accordance with Procedure A ofPractice D 618, for those tests where conditioning is r
48、equired.In cases of disagreement, the tolerances shall be 61C61.8F and 62 % relative humidity.9.1.1 Note that for some hygroscopic materials, such asnylons, the material specifications (for example, SpecificationD 4066) call for testing “dry as-molded specimens.” Suchrequirements take precedence ove
49、r the above routine precon-ditioning to 50 % relative humidity and require sealing thespecimens in water vapor-impermeable containers as soon asmolded and not removing them until ready for testing.9.2 Test ConditionsConduct tests in the standard labora-tory atmosphere of 23 6 2C 73.4 6 3.6F and 50 6 5%relative humidity, unless otherwise specified in the test meth-ods or in this test method. In cases of disagreement, thetolerances shall be 61C 61.8F and 62 % relative humid-ity.10. Procedure10.1 Measure the thickness and wi
