ASTM D6110-2017 red 3750 Standard Test Method for Determining the Charpy Impact Resistance of Notched Specimens of Plastics.pdf

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1、Designation: D6110 10D6110 17Standard Test Method forDetermining the Charpy Impact Resistance of NotchedSpecimens of Plastics1This standard is issued under the fixed designation D6110; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision

2、, 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. Scope*1.1 This test method is used to determine the resistance of plastics to breakage by flexural shock as indic

3、ated by the energyextracted from standardized (see Note 1) pendulum-type hammers, mounted in standardized machines, in breaking standardspecimens with one pendulum swing. This test method requires specimens to be made with a milled notch (see Note 2). The notchproduces a stress concentration which p

4、romotes a brittle, rather than a ductile, fracture. The results of this test method are reportedin terms of energy absorbed per unit of specimen width (see Note 3).NOTE 1The machines with pendulum-type hammers have been standardized in that they must comply with certain requirements including a fixe

5、dheight of hammer fall, which results in a substantially fixed velocity of the hammer at the moment of impact. Hammers of different initial energies(produced by varying their effective weights), however, are recommended for use with specimens of different impact resistance. Moreover, manufacturersof

6、 the equipment are permitted to use different lengths and constructions of pendulums with possible differences in pendulum rigidities resulting (seeSection 5). Be aware that other differences in machine design do exist.NOTE 2The specimens are standardized in that they have a fixed length and fixed d

7、epth, however, the width of the specimens is permitted to varybetween limits. One design of milled notch is allowed. The notch in the specimen serves to concentrate the stress, minimize plastic deformation, and directthe fracture to the part of the specimen behind the notch. Scatter in energy-to-bre

8、ak is thus reduced. Because of differences in the elastic and viscoelasticproperties of plastics, however, response to a given notch varies among materials.NOTE 3Caution must be exercised in interpreting the results of this test method. The following testing parameters have been shown to affect test

9、results significantly: method of specimen fabrication, including but not limited to processing technology, molding conditions, mold design, and thermaltreatment; method of notching; speed of notching tool; design of notching apparatus; quality of the notch; time between notching and test; test speci

10、menthickness; test specimen width under notch; and environmental conditioning.1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety safety, health, and healthenvi

11、ronmental practices and determine theapplicability of regulatory limitations prior to use.NOTE 4This standard resembles ISO 179 in title only. The content is significantly different.1.3 This international standard was developed in accordance with internationally recognized principles on standardizat

12、ionestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D618 Practice for Conditioning Plastics for TestingD647

13、 Practice for Design of Molds for Test Specimens of Plastic Molding Materials (Withdrawn 1994)3D883 Terminology Relating to PlasticsD4000 Classification System for Specifying Plastic MaterialsD4066 Classification System for Nylon Injection and Extrusion Materials (PA)D5947 Test Methods for Physical

14、Dimensions of Solid Plastics SpecimensE691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method3. Terminology3.1 DefinitionsFor definitions related to plastics, see Terminology D883.1 This test method is under the jurisdiction of ASTM Committee D20 on Plastics

15、 and is the direct responsibility of Subcommittee D20.10 on Mechanical Properties.Current edition approved April 1, 2010Dec. 1, 2017. Published April 2010January 2018. Originally approved in 1997. Last previous edition approved in 20082010 asD6110 - 08.D6110 - 10. DOI: 10.1520/D6110-10.10.1520/D6110

16、-17.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3 The last approved version of this historical standard i

17、s referenced on www.astm.org.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 been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends

18、 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.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, We

19、st Conshohocken, PA 19428-2959. United States14. Summary of Test Method4.1 A notched specimen is supported as a horizontal simple beam and is broken by a single swing of the pendulum with theimpact line midway between the supports and directly opposite the notch.5. Significance and Use5.1 Before pro

20、ceeding with this test method, refer to the material specification for the material being tested. Any test specimenpreparation, conditioning, dimensions and testing parameters required by the materials specification shall take precedence overthose required by this test method. Table 1 of Classificat

21、ion D4000 lists theASTM materials standards that currently exist. If thereis no material specification, then the requirements of this test method apply.5.2 The pendulum impact test indicates the energy to break standard test specimens of specified size under stipulated conditionsof specimen mounting

22、, notching (stress concentration), and pendulum velocity at impact.5.3 For this test method, the energy lost by the pendulum during the breakage of the specimen is the sum of the energies requiredto initiate fracture of the specimen; to propagate the fracture across the specimen; to throw the free e

23、nds of the broken specimen(toss energy); to bend the specimen; to produce vibration in the pendulum arm; to produce vibration or horizontal movement ofthe machine frame or base; to overcome friction in the pendulum bearing and in the indicating mechanism, and to overcomewindage (pendulum air drag);

24、to indent or deform, plastically, the specimen at the line of impact; and to overcome the frictioncaused by the rubbing of the striking nose over the face of the bent specimen.NOTE 5The toss energy, or the energy used to throw the free ends of the broken specimen, is suspected to represent a very la

25、rge fraction of the totalenergy absorbed when testing relatively dense and brittle materials. No procedure has been established for estimating the toss energy for the Charpymethod.5.4 For tough, ductile, fiber-filled, or cloth-laminated materials, the fracture propagation energy is usually large com

26、pared to thefracture initiation energy. When testing these materials, energy losses due to fracture propagation, vibration, friction between thestriking nose and the specimen has the potential to become quite significant, even when the specimen is accurately machined andpositioned, and the machine i

27、s in good condition with adequate capacity (see Note 6). Significant energy losses due to bending andindentation when testing soft materials have also been observed.NOTE 6Although the frame and the base of the machine must be sufficiently rigid and massive to handle the energies of tough specimens w

28、ithoutmotion or excessive vibration, the pendulum arm cannot be made very massive because the greater part of its mass must be concentrated near its centerof percussion at its striking nose. Locating the striking nose precisely at the center of percussion reduces the vibration of the pendulum arm wh

29、en usedwith brittle specimens. Some losses due to pendulum arm vibration (the amount varying with the design of the pendulum) will occur with tough specimenseven when the striking nose is properly positioned.5.5 In a well-designed machine of sufficient rigidity and mass, the losses due to vibration

30、and friction in the pendulum bearingand in the indicating mechanism will be very small. Vibrational losses are observed when wide specimens of tough materials aretested in machines of insufficient mass, or in machines that are not securely fastened to a heavy base.5.6 Since this test method permits

31、a variation in the width of the specimens and since the width dictates, for many materials,whether a brittle, low-energy break (as evidenced by little or no drawing down or necking and by a relatively low energyabsorption) or a ductile, high-energy break (as evidenced by considerable drawing or neck

32、ing down in the region behind the notchand by a relatively high energy absorption) will occur, it is necessary that the width be stated in the specification covering thatmaterial and that the width be stated along with the impact value.5.7 This test method requires that the specimen break completely

33、. Results obtained when testing materials with a pendulum thatdoes not have sufficient energy to complete the breaking of the extreme fibers and toss the broken pieces shall be considered adeparture from standard and shall not be reported as a standard result. Impact values cannot be directly compar

34、ed for any twomaterials that experience different types of failure.5.8 The value of this impact test method lies mainly in the areas of quality control and materials specification. If two groupsof specimens of supposedly the same material show significantly different energy absorptions, critical wid

35、ths, or criticaltemperatures, it is permitted to assume that they were made of different materials or were exposed to different processing orconditioning environments. The fact that a material shows twice the energy absorption of another under these conditions of testdoes not indicate that this same

36、 relationship will exist under another set of test conditions.6. Apparatus6.1 Pendulum Impact MachineThe machine shall consist of a massive base on which are mounted a pair of supports forholding the specimen and to which is connected, through a rigid frame and bearings, one of a number of pendulum-

37、type hammershaving an initial energy suitable for use with the particular specimen to be tested (or one basic pendulum designed to accept add-onweights), plus a pendulum holding and releasing mechanism and a mechanism for indicating the breaking energy of the specimen.The specimen anvil, pendulum, a

38、nd frame shall be sufficiently rigid to maintain correct alignment of the striking edge andspecimen, both at the moment of impact and during the propagation of the fracture, and to minimize energy losses due to vibration.The base shall be sufficiently massive so that the impact will not cause it to

39、move. The machine shall be designed, constructed,D6110 172and maintained so that energy losses due to pendulum air drag (windage), friction in the pendulum bearings, and friction and inertiain the indicating mechanism are held to a minimum.6.1.1 PendulumThe simple pendulum shall consist of a single

40、or multi-membered arm with a bearing on one end and a head,containing the striking nose, on the other. Although a large proportion of the mass of the simple pendulum is concentrated in thehead, the arm must be sufficiently rigid to maintain the proper clearances and geometric relationships between t

41、he machine partsand the specimen and to minimize vibrational energy losses, which are always included in the measured impact value. A machinewith a simple pendulum design is illustrated in Fig. 1. Instruments with a compound-pendulum design also have been found tobe acceptable for use. A compound-pe

42、ndulum design is illustrated in Fig. 2.6.1.1.1 The machine shall be provided with a basic pendulum capable of delivering an energy of 2.7 6 0.14 J (2.0 6 0.10 ft-lbf).This pendulum shall be used for specimens that extract less than 85 % of this energy when breaking a specimen. Heavierpendulums or ad

43、ditional weights designed to attach to the basic pendulum shall be provided for specimens that require more energyto break. A series of pendulums such that each has twice the energy of the next lighter one has been found convenient.6.1.1.2 The effective length of the pendulum shall be between 0.325

44、and 0.406 m (12.8 and 16.0 in.) so that the requiredelevation of the striking nose is obtained by raising the pendulum to an angle between 60 and 30 above the horizontal.6.1.2 Striking EdgeThe striking edge (nose) of the pendulum shall be made of hardened steel, tapered to have an includedangle of 4

45、5 6 2 and shall be rounded to a radius of 3.17 6 0.12 mm (0.125 6 0.005 in.). The pendulum shall be aligned in sucha way that when it is in its free hanging position, the center of percussion of the pendulum shall lie within 62.54 mm (0.10 in.)of the middle of the line of contact made by the strikin

46、g nose upon the face of a standard specimen of square cross section. Thedistance from the axis of support to the center of percussion is determined experimentally from the period of motion of smallamplitude oscillations of the pendulum by means of the following equation:L 5g/4pi2!p2 (1)where:L = dis

47、tance from the axis of support to the center of percussion, m,g = local gravitational acceleration (known to an accuracy of one part in one thousand), m/s2pi = 3.1416 (4pi2 = 39.48), andFIG. 1 Simple Beam (Charpy-Type) Impact MachineD6110 173p = period, in s, of a single complete swing (to and fro)

48、determined from at least 20 consecutive and uninterrupted swings. Theangle of swing shall be less than 5 each side of center.6.1.3 Pendulum Holding and Releasing MechanismThe mechanism shall be designed, constructed, and operated so that it willrelease the pendulum without imparting acceleration or

49、vibration to the pendulum. The position of the pendulum holding andreleasing mechanism shall be such that the vertical height of fall of the striking nose shall be 610 6 2 mm (24.0 6 0.0050.1 in.).This will produce a velocity of the striking nose at the moment of impact of approximately 3.46 m (11.4 ft)/s as determined bythe following equation:v 5=2gh (2)where:v = velocity of the striking nose at the moment of impact,g = local gravitational acceleration, andh = vertical height of fall of the striking nose.This assumes no windage or friction.6.1.4 Specimen SupportsT