ASTM E345-1993(2002) Standard Test Methods of Tension Testing of Metallic Foil《金属箔的抗拉试验方法》.pdf

1、Designation: E 345 93 (Reapproved 2002)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 (e) 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 meta

3、llicfoil 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 The values stated in inch-pound units are to be regardedas the standard. The SI values in parentheses

4、are for informa-tion only.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 safety and health practices and determine the applica-bility of regulatory limitations pr

5、ior to use.2. Referenced Documents2.1 ASTM Standards:B 193 Test Method for Resistivity of Electrical ConductorMaterials2E4 Practices for Force Verification of Testing Machines3E6 Terminology Relating to Methods of Mechanical Test-ing3E8 Test Methods for Tension Testing of Metallic Materials3E8M Test

6、 Methods for Tension Testing of Metallic Mate-rials (Metric)3E29 Practice for Using Significant Digits in Test Data toDetermine Conformance with Specifications4E 252 Test Method for Thickness of Thin Foil and Film byWeighing5E 796 Test Method for Ductility Testing of Metallic Foil33. Terminology3.1

7、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 stresses. Thisinformation may be use

8、ful 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 indifferent environments.4.3 These test

9、 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 orreduction of area. However, as s

10、pecimen 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 conform to the requirements of Pra

11、ctices 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 transmit the measured load applied by

12、 the testingmachine to the test specimen. To ensure axial tensile stresswithin the gage length, the axis of the test specimen mustcoincide with the center line of the heads of the testingmachine. Any departure from this center line may introducebending stresses that are not included in the usual str

13、esscomputation (load divided by cross-sectional area).1These 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 Aug. 15, 1993. Published October 1993. Originallypublis

14、hed as E 345 68 T. Last previous edition E 345 87 (1992)e1.2Annual Book of ASTM Standards, Vol 02.03.3Annual Book of ASTM Standards, Vol 03.01.4Annual Book of ASTM Standards, Vol 14.02.5Annual Book of ASTM Standards, Vol 02.02.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West C

15、onshohocken, PA 19428-2959, United States.5.2.2 Wedge GripsTesting machines usually are equippedwith wedge grips. These wedge grips generally furnish asatisfactory means of gripping long specimens of ductilematerials in the thicker foil gages. If, for any reason, one gripof a pair advances farther t

16、han 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 and parallel. For proper gripping, itis desirable that the entire length of the serrated face of eachwedge be in c

17、ontact 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 Face GripsFor foils less than 0.003 in.(0.076 mm) thickness, it may be desirable that the grips havesmooth faces and

18、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 specification for the material being tested. If a Type Aspecimen is used, all specimen dimensions, test procedures,and

19、 calculations shall be in compliance with those shown inTest Methods E8orE8M.6.2 Type A SpecimenType A specimens shall be in accor-dance with the12-in. (12.5-mm) sheet-type specimen shown inFig. 1. To avoid lateral buckling in tests of some materials, theminimum radius of the fillet should be34 in.

20、(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 length.6.3 Type B SpecimensType B specimens shall be inaccordance with the12-in. (12.5-mm) wide parallel sidedspecim

21、en 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 203magnification to determine that the edges are smooth and thatthere are no surface scratches or creases. Specime

22、ns showingdiscernible scratches, creases, or edge discontinuities shall berejected. The milling cutter shall be sharpened or renewedwhen necessary. When machining some thicknesses and tem-pers of material it may be necessary to interleave the sampleswith hard aluminum sheet, a plastic, or other suit

23、able 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, particu-larly of soft and of thin hard metals, may be prepared byshearing, for example, by use of a double-bladed cutter

24、(Fig. 2)or by slitting.6The cutting edges should be lubricated, ifnecessary with a material such as stearic acid in alcohol oranother suitable material. The finished specimens shall beexamined under about 203 magnification to determine that theedges are smooth and there are no surface scratches or c

25、reases.Specimens showing discernible surface scratches, creases, oredge discontinuities shall be rejected.7.3 Specimen Measurement:7.3.1 Thickness: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 thickne

26、ss by weighing in accordancewith Test Method E 252 or by measuring devices. When using6The Thwing-Albert JDC-50 precision cutter available from Thwing-AlbertInstrument Co., 10960 Dutton Rd., Philadelphia, PA 19154, has been found to beacceptable.DimensionsSpecimenType A Type Bin. mm in. mmGGage leng

27、th 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 fillet, 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 2

28、0 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, there 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

29、the center.NOTE 2The dimension T is the thickness of the test specimen as provided for in the applicable material specifications.FIG. 1 Foil Tension Test SpecimenE 345 93 (2002)2Test Method E 252, the specimens themselves shall be weighedwhen it is practical. At least two specimens shall be weighedt

30、ogether. 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 taken from hard mate-rials or materials 0.001 in. (0.0245 mm) and grea

31、ter 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 thickness shallbe computed to the nearest 0.0001 in. (0.0025 mm)

32、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 material, g/in.3(see Appendix).7.3.2 WidthMeasure and record the sp

33、ecimen 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 thespecified tensile strength, whichever is smaller. The speedabove

34、 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 absence of anyspecified limitations on the speed of testing the followin

35、ggeneral 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 application shall not exceed 100 ksi/min (12MPa/s) but shall be g

36、reater 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.7.4.3 The rate of strain shall be 0.06 to 0.5 in./in.min whenthe yi

37、eld 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 strength.7.5 RoundingRound all values of strength to the nearest0.

38、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, as follows:7.6.1 Offset MethodTo determine yield strength by the

39、“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 parallel to oA, andthus locate r, the intersection of the mn with the s

40、tress-straindiagram (Note 4). In reporting values of yield strength obtainedby this method, the specified value of offset used should bestated in parentheses after the term yield strength. Thus: yieldstrength (offset = 0.2 %) = 52 ksi (360 MPa).7.6.2 Extension-Under-Load-MethodFor tests to deter-min

41、e the acceptance or rejection of material whose stress-straincharacteristics are well known from previous tests of similarmaterial in which stress-strain diagrams (Fig. 4) were plotted,the total strain corresponding to the stress at which thespecified offset occurs will be known within satisfactory

42、limits;therefore, in such tests a specified total strain may be used, andFIG. 2 Double-Bladed Cutter for Making Type B SpecimensE 345 93 (2002)3the stress on the specimen, when this total strain is reached, isthe value of the yield strength.NOTE 3Automatic devices are available that determine offset

43、 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 have a yield strength (for that offset), butthe stress at maximum l

44、oad 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 specimen.7.8 Elongation:7.8.1 When elongation is to be determined and Ty

45、pe 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 placednear the specimen edges or in the fillet radii.7.8.2 When elo

46、ngation 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 testing and at fracture. When a Type B specimenis tested using a positiv

47、e 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 elongation is reported, the value shall be shownto the nearest 0.5

48、 %.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

49、 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 outside the gage length.8.1.7 For elongation determinations, the fracture was out-side the middle half of the gage length when using Type Aspecimens.8.1.8 There was a malfunction of the testing equipment.9. Report9.1 The report shall include the following:9.1.1 Metal or alloy, temper, lot or heat number,9.1.2 Test specimen orientation and type,9.1.3 Methods of determinin