1、Designation: D6110 10Standard 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, the ye
2、ar 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 ofplastics to breakage by flexural shock as indicated by t
3、heenergy extracted from standardized (see Note 1) pendulum-type hammers, mounted in standardized machines, in breakingstandard specimens with one pendulum swing. This testmethod requires specimens to be made with a milled notch (seeNote 2). The notch produces a stress concentration whichpromotes a b
4、rittle, rather than a ductile, fracture. The results ofthis test method are reported in terms of energy absorbed perunit of specimen width (see Note 3).NOTE 1The machines with pendulum-type hammers have been stan-dardized in that they must comply with certain requirements including afixed height of
5、hammer fall, which results in a substantially fixed velocityof the hammer at the moment of impact. Hammers of different initialenergies (produced by varying their effective weights), however, arerecommended for use with specimens of different impact resistance.Moreover, manufacturers of the equipmen
6、t are permitted to use differentlengths and constructions of pendulums with possible differences inpendulum rigidities resulting (see Section 5). Be aware that otherdifferences in machine design do exist.NOTE 2The specimens are standardized in that they have a fixedlength and fixed depth, however, t
7、he width of the specimens is permittedto vary between limits. One design of milled notch is allowed. The notchin the specimen serves to concentrate the stress, minimize plasticdeformation, and direct the fracture to the part of the specimen behind thenotch. Scatter in energy-to-break is thus reduced
8、. Because of differencesin the elastic and viscoelastic properties of plastics, however, response toa given notch varies among materials.NOTE 3Caution must be exercised in interpreting the results of thistest method. The following testing parameters have been shown to affecttest results significantl
9、y: method of specimen fabrication, including butnot limited to processing technology, molding conditions, mold design,and thermal treatment; method of notching; speed of notching tool; designof notching apparatus; quality of the notch; time between notching andtest; test specimen thickness; test spe
10、cimen width under notch; andenvironmental conditioning.1.2 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 and health practices and determine the applica-bility
11、 of regulatory limitations prior to use.NOTE 4This standard resembles ISO 179 in title only. The content issignificantly different.2. Referenced Documents2.1 ASTM Standards:2D618 Practice for Conditioning Plastics for TestingD647 Practice for Design of Molds for Test Specimens ofPlastic Molding Mate
12、rials3D883 Terminology Relating to PlasticsD4000 Classification System for Specifying Plastic Materi-alsD4066 Classification System for Nylon Injection and Ex-trusion Materials (PA)D5947 Test Methods for Physical Dimensions of SolidPlastics SpecimensE691 Practice for Conducting an Interlaboratory St
13、udy toDetermine the Precision of a Test Method3. Terminology3.1 DefinitionsFor definitions related to plastics, see Ter-minology D883.4. Summary of Test Method4.1 A notched specimen is supported as a horizontal simplebeam and is broken by a single swing of the pendulum with theimpact line midway bet
14、ween the supports and directly oppositethe notch.5. Significance and Use5.1 Before proceeding with this test method, refer to thematerial specification for the material being tested. Any testspecimen preparation, conditioning, dimensions and testingparameters required by the materials specification
15、shall takeprecedence over those required by this test method. Table 1 ofClassification D4000 lists the ASTM materials standards that1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.10 on Mechanical Properties.Current ed
16、ition approved April 1, 2010. Published April 2010. Originallyapproved in 1997. Last previous edition approved in 2008 as D6110 - 08. DOI:10.1520/D6110-10.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM
17、Standards volume information, refer to the standards Document Summary page onthe ASTM website.3Withdrawn. The last approved version of this historical standard is referencedon www.astm.org.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbo
18、r Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.currently exist. If there is no material specification, then therequirements of this test method apply.5.2 The pendulum impact test indicates the energy to breakstandard test specimens of specified size under stipulatedconditions
19、of specimen mounting, notching (stress concentra-tion), and pendulum velocity at impact.5.3 For this test method, the energy lost by the pendulumduring the breakage of the specimen is the sum of the energiesrequired to initiate fracture of the specimen; to propagate thefracture across the specimen;
20、to throw the free ends of thebroken specimen (toss energy); to bend the specimen; toproduce vibration in the pendulum arm; to produce vibration orhorizontal movement of the machine frame or base; to over-come friction in the pendulum bearing and in the indicatingmechanism, and to overcome windage (p
21、endulum air drag); toindent or deform, plastically, the specimen at the line ofimpact; and to overcome the friction caused by the rubbing ofthe striking nose over the face of the bent specimen.NOTE 5The toss energy, or the energy used to throw the free ends ofthe broken specimen, is suspected to rep
22、resent a very large fraction of thetotal energy absorbed when testing relatively dense and brittle materials.No procedure has been established for estimating the toss energy for theCharpy method.5.4 For tough, ductile, fiber-filled, or cloth-laminated mate-rials, the fracture propagation energy is u
23、sually large comparedto the fracture initiation energy. When testing these materials,energy losses due to fracture propagation, vibration, frictionbetween the striking nose and the specimen has the potential tobecome quite significant, even when the specimen is accuratelymachined and positioned, and
24、 the machine is in good conditionwith adequate capacity (see Note 6). Significant energy lossesdue to bending and indentation when testing soft materialshave also been observed.NOTE 6Although the frame and the base of the machine must besufficiently rigid and massive to handle the energies of tough
25、specimenswithout motion or excessive vibration, the pendulum arm cannot be madevery massive because the greater part of its mass must be concentratednear its center of percussion at its striking nose. Locating the striking noseprecisely at the center of percussion reduces the vibration of the pendul
26、umarm when used with brittle specimens. Some losses due to pendulum armvibration (the amount varying with the design of the pendulum) will occurwith tough specimens even when the striking nose is properly positioned.5.5 In a well-designed machine of sufficient rigidity andmass, the losses due to vib
27、ration and friction in the pendulumbearing and in the indicating mechanism will be very small.Vibrational losses are observed when wide specimens of toughmaterials are tested in machines of insufficient mass, or inmachines that are not securely fastened to a heavy base.5.6 Since this test method per
28、mits a variation in the width ofthe specimens and since the width dictates, for many materials,whether a brittle, low-energy break (as evidenced by little or nodrawing down or necking and by a relatively low energyabsorption) or a ductile, high-energy break (as evidenced byconsiderable drawing or ne
29、cking down in the region behind thenotch and by a relatively high energy absorption) will occur, itis necessary that the width be stated in the specificationcovering that material and that the width be stated along withthe impact value.5.7 This test method requires that the specimen breakcompletely.
30、 Results obtained when testing materials with apendulum that does not have sufficient energy to complete thebreaking of the extreme fibers and toss the broken pieces shallbe considered a departure from standard and shall not bereported as a standard result. Impact values cannot be directlycompared f
31、or any two materials that experience different typesof failure.5.8 The value of this impact test method lies mainly in theareas of quality control and materials specification. If twogroups of specimens of supposedly the same material showsignificantly different energy absorptions, critical widths, o
32、rcritical temperatures, it is permitted to assume that they weremade of different materials or were exposed to differentprocessing or conditioning environments. The fact that amaterial shows twice the energy absorption of another underthese conditions of test does not indicate that this samerelation
33、ship will exist under another set of test conditions.6. Apparatus6.1 Pendulum Impact MachineThe machine shall consistof a massive base on which are mounted a pair of supports forholding the specimen and to which is connected, through arigid frame and bearings, one of a number of pendulum-typehammers
34、 having an initial energy suitable for use with theparticular specimen to be tested (or one basic pendulumdesigned to accept add-on weights), plus a pendulum holdingand releasing mechanism and a mechanism for indicating thebreaking energy of the specimen. The specimen anvil, pendu-lum, and frame sha
35、ll be sufficiently rigid to maintain correctalignment of the striking edge and specimen, both at themoment of impact and during the propagation of the fracture,and to minimize energy losses due to vibration. The base shallbe sufficiently massive so that the impact will not cause it tomove. The machi
36、ne shall be designed, constructed, and main-tained so that energy losses due to pendulum air drag (wind-age), 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 asingle or multi-membered arm
37、with a bearing on one end anda head, containing the striking nose, on the other. Although alarge proportion of the mass of the simple pendulum isconcentrated in the head, the arm must be sufficiently rigid tomaintain the proper clearances and geometric relationshipsbetween the machine parts and the
38、specimen and to minimizevibrational energy losses, which are always included in themeasured impact value. A machine with a simple pendulumdesign is illustrated in Fig. 1. Instruments with a compound-pendulum design also have been found to be acceptable foruse. A compound-pendulum design is illustrat
39、ed in Fig. 2.6.1.1.1 The machine shall be provided with a basic pendu-lum capable of delivering an energy of 2.7 6 0.14 J (2.0 60.10 ft-lbf). This pendulum shall be used for specimens thatextract less than 85 % of this energy when breaking a speci-men. Heavier pendulums or additional weights designe
40、d toattach to the basic pendulum shall be provided for specimensthat require more energy to break. A series of pendulums suchthat each has twice the energy of the next lighter one has beenfound convenient.D6110 1026.1.1.2 The effective length of the pendulum shall bebetween 0.325 and 0.406 m (12.8 a
41、nd 16.0 in.) so that therequired elevation of the striking nose is obtained by raising thependulum to an angle between 60 and 30 above the horizontal.6.1.2 Striking EdgeThe striking edge (nose) of the pen-dulum shall be made of hardened steel, tapered to have anincluded angle of 45 6 2 and shall be
42、rounded to a radius of3.17 6 0.12 mm (0.125 6 0.005 in.). The pendulum shall bealigned in such a way that when it is in its free hangingposition, the center of percussion of the pendulum shall liewithin 62.54 mm (0.10 in.) of the middle of the line of contactmade by the striking nose upon the face o
43、f a standard specimenof square cross section. The distance from the axis of supportto the center of percussion is determined experimentally fromthe period of motion of small amplitude oscillations of thependulum by means of the following equation:L 5g/4p2! p2(1)where:L = distance from the axis of su
44、pport to the center ofpercussion, m,g = local gravitational acceleration (known to an accuracyof one part in one thousand), m/s2p = 3.1416 (4p2= 39.48), andp = period, in s, of a single complete swing (to and fro)determined from at least 20 consecutive and uninter-rupted swings. The angle of swing s
45、hall be less than 5each side of center.6.1.3 Pendulum Holding and Releasing MechanismThemechanism shall be designed, constructed, and operated so thatit will release the pendulum without imparting acceleration orvibration to the pendulum. The position of the pendulumholding and releasing mechanism s
46、hall be such that the verticalheight of fall of the striking nose shall be 610 6 2 mm (24.06 0.005 in.). This will produce a velocity of the striking noseFIG. 1 Simple Beam (Charpy-Type) Impact MachineFIG. 2 Example of CompoundPendulumType MachineD6110 103at the moment of impact of approximately 3.4
47、6 m (11.4 ft)/s asdetermined by the 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 SupportsThe test specimen sh
48、all be sup-ported against two rigid anvils in such a position that its centerof gravity and the center of the notch shall lie on tangent to thearc of travel of the center of percussion of the pendulum drawnat the position of impact. The edges of the anvils shall berounded to a radius of 3.17 6 0.12
49、mm (0.125 6 0.005 in.) andthe anvils lines of contact (span) with the specimen shall be101.6 6 0.5 mm (4.0 6 0.02 in.) apart (see Fig. 3). Somemachine manufacturers supply a jig for positioning the speci-men on the supports.NOTE 7Some machines currently in use employ a 108.0-mm span.Data obtained under these conditions are valid.46.1.5 IndicatorMeans shall be provided for determiningthe energy expended by the pendulum in breaking the speci-men. This is accomplished using either a pointer and dialmechanism or an electronic system consisting of a digitalindicator
