ASTM E345-1993(2008) 781 Standard Test Methods of Tension Testing of Metallic Foil《金属材料的抗拉标准试验方法》.pdf

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1、Designation: E 345 93 (Reapproved 2008)Standard Test Methods ofTension Testing of Metallic Foil1This standard is issued under the fixed designation E 345; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A

2、 number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 These test methods cover the tension testing of metal

3、licfoil at room temperature in thicknesses less than 0.006 in.(0.150 mm).NOTE 1Exception to these methods may be necessary in individualspecifications or test methods for a particular material.1.2 UnitsThe values stated in inch-pound units are to beregarded as standard. The values given in parenthes

4、es aremathematical conversions to SI units that are provided forinformation only and are not considered standard.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 sa

5、fety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2B 193 Test Method for Resistivity of Electrical ConductorMaterialsE4 Practices for Force Verification of Testing MachinesE6 Terminology Relating to Methods of

6、Mechanical Test-ingE 8/E 8M Test Methods for Tension Testing of MetallicMaterialsE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE 252 Test Method for Thickness of Foil, Thin Sheet, andFilm by Mass MeasurementE 796 Test Method for Ductility Testing o

7、f Metallic Foil3. Terminology3.1 The definitions of terms relating to tension testingappearing in Terminology E6apply to the terms used in thesemethods of tension testing.4. Significance and Use4.1 Tension tests provide information on the strength andductility of materials under uniaxial tensile str

8、esses. Thisinformation may be useful in comparisons of materials, alloydevelopment, quality control, and design.4.2 The results of tension tests from selected portions of apart or material may not totally represent the strength andductility of the entire end product of its in-service behavior indiff

9、erent environments.4.3 These test methods are considered satisfactory for ac-ceptance testing of commercial shipments since the methodshave been used extensively for these purposes.4.4 Tension tests provide a means to determine the ductilityof materials through the measurement either of elongation o

10、rreduction of area. However, as specimen thickness is reduced,tension tests may become less useful for the determination ofductility. For these purposes Test Method E 796 presents analternative procedure for measuring ductility.5. Apparatus5.1 Testing MachinesMachines used for tension testingshall c

11、onform to the requirements of Practices E4. The loadsused in determining tensile strength, yield strength, and yieldpoint shall be within the verified loading range of the testingmachine as defined in Practices E4.5.2 Gripping Devices:5.2.1 GeneralVarious types of gripping devices may beused to tran

12、smit the measured load applied by the testingmachine to the test specimen. To ensure axial tensile stress1These test methods are under the jurisdiction of ASTM Committee E28 onMechanical Testing and are the direct responsibility of Subcommittee E28.04 onUniaxial Testing.Current edition approved May

13、1, 2008. Published December 2008. Originallyapproved in 1968. Last previous edition approved in 2002 as E 345 87 (2002).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

14、 to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.within the gage length, the axis of the test specimen mustcoincide with the center line of the heads of the testingmachine. An

15、y departure from this center line may introducebending stresses that are not included in the usual stresscomputation (load divided by cross-sectional area).5.2.2 Wedge GripsTesting machines usually are equippedwith wedge grips. These wedge grips generally furnish asatisfactory means of gripping long

16、 specimens of ductilematerials in the thicker foil gages. If, for any reason, one gripof a pair advances farther than the other as the grips tighten, anundesirable bending stress may be introduced. When liners areused behind the wedges, they must be of the same thicknessand their faces must be flat

17、and parallel. For proper gripping, itis desirable that the entire length of the serrated face of eachwedge be in contact with the specimen. A buffer material suchas 320-grit silicon carbide paper may be inserted between thespecimen and serrated faces to minimize tearing of specimens.5.2.3 Smooth Fac

18、e GripsFor foils less than 0.003 in.(0.076 mm) thickness, it may be desirable that the grips havesmooth faces and that the gripping pressure be about 100 psi(0.7 MPa) for each 0.001 in. (0.025 mm) of specimen thick-ness.6. Test Specimen6.1 GeneralTest specimens shall be prescribed in theproduct spec

19、ification for the material being tested. If a Type Aspecimen is used, all specimen dimensions, test procedures,and calculations shall be in compliance with those shown inTest Methods E 8/E 8M.6.2 Type A SpecimenType A specimens shall be in accor-dance with the12-in. (12.5-mm) sheet-type specimen sho

20、wn inFig. 1. To avoid lateral buckling in tests of some materials, theminimum radius of the fillet should be34 in. (19 mm), or thewidth of the grip ends should be only slightly larger than thewidth of the reduced section, or both; and the reduced sectionshould be at least 20 % longer than the gage l

21、ength.6.3 Type B SpecimensType B specimens shall be inaccordance with the12-in. (12.5-mm) wide parallel sidedspecimen shown in Fig. 1.7. Procedures7.1 Type A Specimen PreparationThe specimens can bemachined in packs by use of a milling-type cutter. Themachined specimens shall be examined under about

22、 203magnification to determine that the edges are smooth and thatthere are no surface scratches or creases. Specimens showingdiscernible scratches, creases, or edge discontinuities shall berejected. The milling cutter shall be sharpened or renewedwhen necessary. When machining some thicknesses and t

23、em-pers of material it may be necessary to interleave the sampleswith hard aluminum sheet, a plastic, or other suitable material.For some materials it may be desirable to polish the edges ofthe specimens, either mechanically or by electropolishing.7.2 Type B Specimen PreparationThe specimens, partic

24、u-larly of soft and of thin hard metals, may be prepared byshearing, for example, by use of a double-bladed cutter (Fig. 2)or by slitting.3The cutting edges should be lubricated, ifnecessary with a material such as stearic acid in alcohol oranother suitable material. The finished specimens shall be3

25、The sole source of supply of the Thwing-Albert JDC-50 precision cutter knownto the committee at this time is Thwing-Albert Instrument Co., 10960 Dutton Rd.,Philadelphia, PA19154. If you are aware of alternative suppliers, please provide thisinformation to ASTM International Headquarters. Your commen

26、ts will receivecareful consideration at a meeting of the responsible technical committee,1whichyou may attend.DimensionsSpecimenType A Type Bin. mm in. mmGGage length 2.000 6 0.005 50.0 6 0.1 5 125WWidth 0.500 6 0.010 12.50 6 0.25 0.500 12.5TThickness thickness of foil thickness of foilRRadius of fi

27、llet, min34 19 . .LOverall Length, min 8 200 9 230ALength of reduced section, min 214 60 . .BLength of grip section, min 2 50 . .CWidth of grip section, approx.34 20 0.500 12.5NOTE 1For TypeAspecimens, the ends of the reduced section shall not differ in width by more than 0.002 in. (0.05 mm).Also, t

28、here may be a gradualdecrease in width from the ends to the center, but the width at either end shall not be more than 0.005 in. (0.10 mm) larger than the width at the center.NOTE 2The dimension T is the thickness of the test specimen as provided for in the applicable material specifications.FIG. 1

29、Foil Tension Test SpecimenE 345 93 (2008)2examined under about 203 magnification to determine that theedges are smooth and there are no surface scratches or creases.Specimens showing discernible surface scratches, creases, oredge discontinuities shall be rejected.7.3 Specimen Measurement:7.3.1 Thick

30、ness:7.3.1.1 Thickness of specimens taken from soft foils or fromfoils 0.002 in. (0.05 mm) and thinner shall be determined to anaccuracy of 2 % of the thickness by weighing in accordancewith Test Method E 252 or by measuring devices. When usingTest Method E 252, the specimens themselves shall be wei

31、ghedwhen it is practical. At least two specimens shall be weighedtogether. When Type B specimens are not used for weighing, asample in accordance with Test Method E 252 may be usedwhen taken from an area adjacent to that from which the testspecimens were taken.7.3.1.2 The thickness of specimens take

32、n from hard mate-rials or materials 0.001 in. (0.0245 mm) and greater inthickness may be determined by use of an optimeter, anelectrical-type measuring device, or vernier micrometer, pro-vided that the thickness is measured to at least the nearest 2 %.NOTE 2When specimens or samples are weighed, the

33、 thickness shallbe computed to the nearest 0.0001 in. (0.0025 mm) and preferably to thenearest 0.00001 in. (0.00025 mm) by use of the formula:T 5 W/AD (1)where:where:T = thickness of specimen or sample, in.,W = weight of specimen or sample, g,A = area of specimen or sample, in.2, andD = density of m

34、aterial, g/in.3(see Appendix).7.3.2 WidthMeasure and record the specimen width di-mension to the nearest 0.001 in. (0.025 mm).7.4 Speed of TestingUnless otherwise specified, any con-venient speed of testing may be used up to one half thespecified yield strength or yield point, or up to one quarter t

35、hespecified tensile strength, whichever is smaller. The speedabove this point shall be within the limits specified. If differentspeed limitations are required in determining yield strength,yield point, tensile strength, and elongation, they should bestated in the product specification. In the absenc

36、e of anyspecified limitations on the speed of testing the followinggeneral rules shall apply:7.4.1 The speed of testing shall be such that the loads andstrains used in obtaining the test results are accurately indi-cated.7.4.2 When yield strength or yield point is to be determined,the rate of stress

37、 application shall not exceed 100 ksi/min (12MPa/s) but shall be greater than 1 ksi/min (1.2 MPa/s). Thespeed may be increased after removal of the extensometer, butit shall not exceed 0.5 in./in. (mm/mm) of reduced section (ordistance between grips for specimens not having reducedsection) per min.7

38、.4.3 The rate of strain shall be 0.06 to 0.5 in./in.min whenthe yield strength is not being determined, except when theproduct specification requires a different speed.7.4.4 When yield strength is to be determined, the strain rateshall be 0.002 to 0.010 in./in.min until the stress is above theyield

39、strength.7.5 RoundingRound all values of strength to the nearest0.1 ksi (0.7 MPa) and each value of elongation to the nearest0.5 %, unless specified otherwise, in accordance with therounding method of Practice E29.7.6 Yield StrengthDetermine yield strength by the offsetor extension-under-load method

40、, as follows:7.6.1 Offset MethodTo determine yield strength by the“offset method,” it is necessary to secure data (autographic ornumerical) from which a stress-strain diagram may be drawn.Then on the stress-strain diagram (Fig. 3) lay off om equal tothe specified value of the “offset,” draw mn paral

41、lel to oA, andthus locate r, the intersection of the mn with the stress-strainFIG. 2 Double-Bladed Cutter for Making Type B SpecimensE 345 93 (2008)3diagram (Note 4). In reporting values of yield strength obtainedby this method, the specified value of offset used should bestated in parentheses after

42、 the term yield strength. Thus: yieldstrength (offset = 0.2 %) = 52 ksi (360 MPa).7.6.2 Extension-Under-Load-MethodFor tests to deter-mine the acceptance or rejection of material whose stress-straincharacteristics are well known from previous tests of similarmaterial in which stress-strain diagrams

43、(Fig. 4) were plotted,the total strain corresponding to the stress at which thespecified offset occurs will be known within satisfactory limits;therefore, in such tests a specified total strain may be used, andthe stress on the specimen, when this total strain is reached, isthe value of the yield st

44、rength.NOTE 3Automatic devices are available that determine offset yieldstrength without plotting a stress-strain curve. Such devices may be usedif their accuracy has been demonstrated to be acceptable.NOTE 4If the load drops before the specified offset is reached,technically the material does not h

45、ave a yield strength (for that offset), butthe stress at maximum load before the specified offset is reached may bereported as the yield strength.7.7 Tensile StrengthCalculate the tensile strength by di-viding the maximum load carried by the specimen by theoriginal cross-sectional area of the specim

46、en.7.8 Elongation:7.8.1 When elongation is to be determined and Type Aspecimens are used, the 2-in. gage length may be lightlymarked on the specimen by scribing fine lines of a 1-mil radiusscriber and a precision ground template. The scribed linesshould be about18 in. (3 mm) long and should not be p

47、lacednear the specimen edges or in the fillet radii.7.8.2 When elongation is to be determined and Type Bspecimens are used, the minimum and preferred distancebetween grips shall be 5 in. (125 mm), and the elongation maybe determined from the differences in the distance between thegrips before testin

48、g and at fracture. When a Type B specimenis tested using a positive head-speed type testing machine, theelongation may be taken from the loadelongation graph com-puted by the equation:Head speed 3 inches of chart (2)Elongation, % 5head speed 3 inches of chartchart speed 3 gage length3 1007.8.3 When

49、elongation is reported, the value shall be shownto the nearest 0.5 %.8. Replacement of Specimens8.1 A test specimen may be discarded and a replacementspecimen taken from the same sample remnant, if possible, inthe following cases:8.1.1 The original specimen had surface scratches orcreases.8.1.2 The original specimen had a poorly machined surface.8.1.3 The original specimen had the wrong dimensions.8.1.4 The specimens properties were changed because ofpoor machining practice.8.1.5 The test procedure was incorrect.8.1.6 The fracture was outsi