ASTM D1415-2018 Standard Test Method for Rubber Property&x2014 International Hardness.pdf

1、Designation: D1415 18Standard Test Method forRubber PropertyInternational Hardness1This standard is issued under the fixed designation D1415; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in pa

2、rentheses 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 U.S. Department of Defense.1. Scope1.1 This test method covers a procedure for measuring thehardness

3、 of vulcanized or thermoplastic rubber. The hardnessis obtained by the difference in penetration depth of a specifieddimension ball under two conditions of contact with the rubber:(1) with a small initial force and (2) with a much larger finalforce. The differential penetration is taken at a specifi

4、ed timeand converted to a hardness scale value.1.2 This test method is technically similar to ISO 48.1.3 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, health

5、, and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of Internatio

6、nal Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D1349 Practice for RubberStandard Conditions for Test-ingD2240 Test Method for Rubber PropertyDurometer Hard-nessD4483 Practice for

7、Evaluating Precision for Test MethodStandards in the Rubber and Carbon Black ManufacturingIndustries2.2 International Standard:3ISO 48 Rubber, Vulcanized or ThermoplasticDetermination of Hardness (Hardness between 10 and 100IRHD)3. Summary of Test Methods3.1 Four procedures are given to accommodate

8、specimensof different dimensions hardness of vulcanized or thermoplas-tic rubbers on flat surfaces:Type S1 and S2, Standard hardness tests;Type M, Micro-hardness tests;Type L, Low hardness test;Type H, High hardness test.3.1.1 Types S1 and S2 (refer to Table 1)The standard testfor hardness is the ap

9、propriate method for specimens having athickness described in Section 6, and is appropriate for thosehaving a hardness of 35 IRHD to 85 IRHD. It may be used forthose in the range of 30 IRHD to 95 IRHD.NOTE 1The hardness values obtained by Types S and S1, within theranges of 85 IRHD to 95 IRHD and 30

10、 IRHD to 35 IRHD may not agreewith those obtained using Types H or L. The differences are not generallyconsidered significant.3.1.2 Type M (refer to Table 1)The micro-hardness test isa scaled-down version of Type S1 and S2, which permit testingof thinner and smaller specimens. It is applicable for s

11、pecimenshaving a thickness described in Section 6, and a hardness of 35IRHD to 85 IRHD. It may be used for those in the range of 30IRHD to 95 IRHD.NOTE 2The hardness values obtained by Type M may not agree withthose obtained using Types S1 or S2 due to the effects of surface variationsor specimen co

12、nfiguration.3.1.3 Type LThe appropriate method for specimens hav-ing a thickness described in Section 6, and a hardness of 10IRHD to 35 IRHD.3.1.4 Type HThe appropriate method for specimens hav-ing a thickness described in Section 6, and a hardness of 85IRHD to 100 IRHD.3.2 In all procedures, the ha

13、rdness in International RubberHardness Degrees (IRHD) is derived from the difference in1This test method is under the jurisdiction of ASTM Committee D11 on Rubberand Rubber-like Materials and is the direct responsibility of Subcommittee D11.10on Physical Testing.Current edition approved June 1, 2018

14、. Published September 2018. Originallyapproved in 1956. Last previous edition approved in 2012 as D1415 06 (2012).DOI: 10.1520/D1415-18.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume in

15、formation, refer to the standards Document Summary page onthe ASTM website.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis

16、international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT

17、) Committee.1penetrations and a table or graph constructed from the table. Inthe micro-tester procedure, the difference in penetration mustfirst be multiplied by scale factor 6. Alternatively, the penetra-tion measuring instrument may be calibrated directly in IRHD.4. Significance and Use4.1 The Int

18、ernational Hardness test is based on measure-ment of the penetration of a rigid ball into the rubber specimenunder specified conditions. The measured penetration is con-verted into IRHD, the scale of degrees being so chosen that 0represents a material having an elastic modulus of zero, and100 repres

19、ents a material of infinite elastic modulus.4.1.1 The scale also fulfills the following conditions overmost of the normal range of hardness: one IRHD rangerepresents approximately the same proportionate difference inYoungs modulus, and for rubber vulcanizates in the usualrange of resilience, reading

20、s in IRHD are comparable withthose given by a TypeAdurometer (Test Method D2240) whentesting standard specimens.4.1.1.1 The term “usual range of resilience” is used toexclude those compounds that have unusually high rates ofstress relaxation or deformational hysteresis. For suchcompounds, difference

21、s in the dwell time in the two hardnesstests (Test Methods D2240 and D1415) result in differences inhardness values. Readings may not be comparable whentesting curved or irregularly shaped test specimens.4.1.2 For substantially elastic isotropic materials like well-vulcanized natural rubbers, the ha

22、rdness in IRHD bears aknown relation to Youngs modulus, although for markedlyplastic or anisotropic rubbers the relationship will be lessprecisely known.4.1.3 The relation between the difference of penetration andthe hardness expressed in IRHD is based on the following:4.1.3.1 The relation4between p

23、enetration and Youngsmodulus for a perfectly elastic isotropic material:D 5 61.5 R20.48F/E#0.742 f/E#0.74! (1)where:D = known relationship for a perfectly elastic isotropicmaterial, between indentation,R = radium of the ball, mm,F = total indenting force,E = Youngs modulus expressed in megapascals,

24、andf = contact force4.1.3.2 Use of a probit (integrated normal error) curve torelate log10M and hardness in IRHD, as shown in Fig. 1. Thiscurve is defined as follows:4.1.3.3 The value of log10M corresponding to the midpointof the curve is equal to 0.364, that is, M = 2.31 MPa or 335 psi.4.1.3.4 The

25、maximum slope is equal to 57 IRHD per unitincrease in log10M.5. Apparatus5.1 The essential parts of the apparatus are as follows, theappropriate dimensions and loads being given in Table 1:5.1.1 Vertical Plunger, terminating in a rigid ball.5.1.2 Force Applicator, for applying a minor force and amaj

26、or force to the ball, the mass of the plunger, and of anyfittings attached to it, and the force of any spring acting on itshall be included in determining the minor and major forces.This is in order that the forces actually applied to the ball shallbe as specified.5.1.3 Measuring DeviceA mechanical,

27、 optical, or electri-cal device graduated either in standard units of length or inIRHD for measuring the increase in depth of penetration of theplunger caused by the major load.5.1.4 FootA flat annular-shaped foot that is rigidly fas-tened to the penetration-measuring device and normal to theaxis of

28、 the plunger, and which during the test is forced againstthe specimen in order to determine accurately the position ofthe upper surface.5.1.5 Vibrating DeviceFor example, an electrically oper-ated buzzer, for gently vibrating the apparatus to overcome anyslight friction; this should not exceed 5 % o

29、f the minor load.This device may be omitted on apparatus without any friction.4This relation is approximate and is included as an indication.TABLE 1 Apparatus RequirementsNOTE 1In Type M micro-hardness testing using instruments in which the test piece table is pressed upwards by a spring, the value

30、of the force onfoot is that acting during the period of application of the total indenting force. Before the indenting force increment of 0.145 N is applied, the force onthe foot is greater by this amount, and hence is 0.38 0.03 N.Type S1 Type S2 Type M Type L Type HDiameter of ball,mm2.380.01 2.500

31、.01 0.3950.005 5.00.01 1.00.01Minor force on ball,NA0.30 0.02 0.29 0.02 0.0083 0.0005 0.3 0.02 0.3 0.02Major force on ball,NA5.23 0.01 5.4 0.01 0.1455 0.0005 5.4 0.01 5.4 0.01Total force on ball,NA5.530.03 5.70.03 0.1530.001 5.70.03 5.70.03Outside diameter offoot, mm20 1 20 1 3.35 0.15 22 1.0 20 1.0

32、Inside diameter offoot, mm61 61 1.000.15 101.0 61.0Force on foot, NB8.3 1.5 8.3 1.5 0.235 0.03C8.31.5 8.31.5AIncludes frictional forces in apparatus.BThe force should be adjusted within these limits to the actual area of the foot so that the pressure in the specimen is 30 0.5 kPa.CForce on foot duri

33、ng application of total force on ball; force on foot during application of minor force on ball, 0.2 N minimum, 0.4 N maximum.D1415 1826. Test Specimen6.1 Tests intended to be comparable must be made onspecimens of the same thickness that have smooth, flat, andparallel upper and lower surfaces. Up to

34、 three specimens maybe plied to obtain the required thickness. The dimensions of thespecimen depend on the test type being used to measure thehardness.6.2 Types S1 and S2The Types S1 and S2 specimens shallbe between 8 and 10 mm in thickness. Nonstandard specimensmay be either thicker or thinner but

35、in no case less than 2 mmthick. The lateral dimensions of both standard and nonstandardspecimens shall be such that no test is made at a distance fromthe edge of the specimen less than the appropriate distanceshown in Table 2.6.3 Type MThe Type M specimen micro-hardness testsshall be 2 6 0.5 mm in t

36、hickness. Nonstandard specimens maybe either thicker or thinner but in no case less than 1 mm thick.The lateral dimensions of both standard and nonstandardspecimens shall be such that no test is made at a distance fromthe edge of less than 2 mm. When specimens thicker than 4 mmare tested on the micr

37、o tester because lateral dimensions or areaof flatness do not permit testing on a standard tester, the testshall be made at a distance from the edge as great as possible.Curved specimens, for example, O-rings, may be tested withthe micro-hardness tester if the specimens are mounted in sucha manner a

38、s to prevent movement during the test, but thevalues obtained may not be comparable to those obtained withflat specimens.6.4 Type LThe Type L specimens shall be 10 to 15 mm inthickness. Standard specimens may be either thicker or thinnerbut in no case less than 2 mm. Nonstandard specimens may beeith

39、er thicker or thinner but in no case less than 6 mm. Thelateral dimensions of both standard and nonstandard specimensshall be such that no test is made at a distance from the edgeof the specimen less than the appropriate distance shown inTable 2.6.5 Type HRefer to 6.2 (Types S1 and S2).7. Test Tempe

40、rature7.1 The test shall be normally carried out at 23 6 2C (73.46 3.6F). The specimens shall be maintained at the testtemperature for at least 3 h immediately prior to testing.Specimens that are sensitive to atmospheric moisture shall beconditioned in an atmosphere controlled to 50 6 5 % relativehu

41、midity (RH%) for at least 24 h. When tests are made athigher or lower temperatures, the specimens shall be main-tained at the conditions of test for a period of time sufficient toreach temperature equilibrium with the testing chamber, andthe temperatures shall be chosen from those specified inPracti

42、ce D1349, or as otherwise agreed upon between customerand supplier.FIG. 1 Point Curve to Relate Log10M and the Hardness in IRHDTABLE 2 Minimum Distance from Edge of Specimen at WhichTest is Made (All types except M)Total Thickness of Specimen Minimum Distance from Edgemm in. mm in.4 0.16 7.0 0.286 0

43、.25 8.0 0.318 0.3 9.0 0.3510 0.4 10.0 0.4015 0.6 11.5 0.4525 1.0 13.0 0.50D1415 1838. Procedure8.1 Condition the specimen in accordance with 7.1. Slightlydust the upper and lower surfaces of the test specimen withtalc. Support the specimen on a horizontal rigid surface, andlower the foot to rest on

44、the surface of the specimen. Press theplunger, with the minor force on the indenting ball, verticallyonto the specimen for 5 s.8.2 If the gauge is graduated directly in IRHD, turn thebezel of the gauge so that the pointer indicates 100 (exercisecare to avoid exerting any vertical pressure on the gau

45、ge). Addthe major force to the plunger and maintain the total force onthe ball for 30 s (Note 3). Record the reading on the gauge asthe hardness in IRHD.NOTE 3During the loading periods, the apparatus shall be gentlyvibrated to overcome any friction.8.3 If the measuring device is graduated in inch u

46、nits, recordthe movement of the plunger caused by application of themajor load for 30 s. If the Type M micro-hardness tester isused, refer to the notes in Table 3a. Convert the value obtainedinto IRHD by using Table 3a or a graph constructed therefrom.8.4 If the measuring device is graduated in metr

47、ic units, thedifferential indentation, D, (in millimeters) of the plungercaused by the additional indenting force (the major load) for 30s, shall be noted. If the Type M micro-hardness tester is used,refer to Table 3c, as given in Table 3b for Types S1 and S2,Table 3d for Type H, and Table 3e for Ty

48、pe L. Convert thevalue obtained into IRHD by using Table 3aTable 3eoragraph constructed therefrom.8.5 Make one measurement at each of three or five differentpoints distributed evenly over the specimen. Take the medianof these measurements rounded to the nearest displayed unit ofIRHD (whole numbers f

49、or analog instruments and 0.1 units fordigital instruments, if so equipped), and record the result as thehardness value.9. Report9.1 Report the following information:9.1.1 Hardness expressed in IRHD. Values from curved orirregularly shaped specimens shall be quoted as apparenthardness,9.1.2 Dimensions of the specimen, if a singular entity; thenumber of pieces, that is, one, two, or three; and theirindividual dimensions when plied. In the case of curved orirregularly shaped specimens: specimen descri