1、Designation: D1415 06 (Reapproved 2012)Standard 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 revisi
2、on. A 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 This test method covers a procedure for measurin
3、g thehardness 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
4、 at a specified 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 s
5、afety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1349 Practice for RubberStandard Temperatures forTestingD2240 Test Method for Rubber PropertyDurometerHardnessD4483 Practice for Evaluating Precision for Tes
6、t 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 specimensof different dimens
7、ions 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 appropriate method for specime
8、ns 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 IRHD to 35 IRHD may not agr
9、eewith 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 specimenshaving a thickness d
10、escribed 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 variations1This test method is under the jurisdictio
11、n of ASTM Committee D11 on Rubberand is the direct responsibility of Subcommittee D11.10 on Physical Testing.Current edition approved Jan. 1, 2012. Published March 2012. Originallyapproved in 1956. Last previous edition approved in 2006 as D1415 06. DOI:10.1520/D1415-06R12.2For referenced ASTM stand
12、ards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor,
13、 New York, NY 10036.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.or specimen configuration.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
14、 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 hardness in International RubberHardness Degrees (IRHD) is derived from the difference inpenetrations and a table or graph constructed from the table. In
15、the 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 International Hardness test is based on measure-ment of the penetration of a rig
16、id 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 represents a material of infinite elastic modulus.4.1.1 The scale also fulfills the
17、 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, readings in IRHD are comparable withthose given by a TypeAdurometer (Test Method D22
18、40) 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 such com-pounds, differences in the dwell time in the two hardness tests(Test Methods D2240 and D1415)
19、 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 hardness in IRHD bears aknown relation to Youngs modulus, although for marked
20、lyplastic 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 penetration and Youngsmodulus for a perfectly elastic isotropic material:D 5
21、 61.5 R20.48F/E0.742 f/E0.74! (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, andf = contact force4.1.3.2 Use of a probit (integrated normal error) curve t
22、orelate 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 maximum slope is equal to 57 IRHD per unitincrease in log10M.5. Apparatus5.1
23、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 amajor force to the ball, the mass of the plunger, and of anyfittings attached to
24、 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, optical, or electri-cal device graduated either in standard units of length
25、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 the4This relation is approximate and is included as an indication.TABLE 1 Apparatus Req
26、uirementsNOTEIn Type M micro-hardness testing using instruments in which the test piece table is pressed upwards by a spring, the value of the force on footis that acting during the period of application of the total indenting force. Before the indenting force increment of 0.145 N is applied, the fo
27、rce on thefoot is greater by this amount, and hence is 0.38 6 0.03 N.Type S1 Type S2 Type M Type L Type HDiameter of ball,mm2.38 6 0.01 2.50 6 0.01 0.395 6 0.005 5.0 6 0.01 1.0 6 0.01Minor force on ball,NA0.30 6 0.02 0.29 6 0.02 0.00836 0.0005 0.3 6 0.02 0.3 6 0.02Major force on ball,NA5.23 6 0.01 5
28、.4 6 0.01 0.1455 6 0.0005 5.4 6 0.01 5.4 6 0.01Total force on ball,NA5.53 6 0.03 5.7 6 0.03 0.153 6 0.001 5.7 6 0.03 5.7 6 0.03Outside diameter offoot, mm20 6 1206 1 3.356 0.15 22 6 1.0 20 6 1.0Inside diameter offoot, mm6 6 166 1 1.006 0.15 10 6 1.0 6 6 1.0Force on foot, NB8.3 6 1.5 8.3 6 1.5 0.2356
29、 0.03C8.3 6 1.5 8.3 6 1.5AIncludes 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 6 0.5 kPa.CForce on foot during application of total force on ball; force on foot during application of minor
30、force on ball, 0.2 N minimum, 0.4 N maximum.D1415 06 (2012)2axis of 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 app
31、aratus to overcome anyslight friction; this should not exceed 5 % of the minor load.This device may be omitted on apparatus without any friction.6. Test Specimen6.1 Tests intended to be comparable must be made onspecimens of the same thickness that have smooth, flat, andparallel upper and lower surf
32、aces. Up to 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 t
33、hinner but 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
34、0.5 mm in thickness. 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
35、on the micro 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 suc
36、ha manner as 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
37、 may beeither 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.
38、 Test Temperature7.1 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 %
39、 relativehumidity (RH%) for at least 24 h. When tests are made atFIG. 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 0.2
40、5 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 06 (2012)3higher 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 ch
41、osen from those specified inPractice D1349, or as otherwise agreed upon between customerand supplier.8. 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 th
42、e foot to rest on 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 p
43、ressure on the gauge). 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 g
44、raduated in inch units, recordthe movement of the plunger caused by application of themajor load for 30 s. If the Type M micro-hardness tester isused, multiply this movement by the scale factor of 6. Convertthe value obtained into IRHD by using Table 3 or a graphconstructed therefrom.8.4 If the meas
45、uring device is graduated in metric units, thedifferential indentation, D, (in hundredths of a millimetre) ofthe plunger caused by the additional indenting force (the majorload) for 30 s, shall be noted. If the Type M micro-hardnesstester is used, multiply this movement by the scale factor of 6,as g
46、iven in Table 3 (a) for Types S1 and S2, Table 3 (b) forType H, and Table 3 (c) for Type L. Convert the value obtainedinto IRHD by using Table 3 (a-c) or a graph constructedtherefrom.8.5 Make one measurement at each of three or five differentpoints distributed evenly over the specimen. Take the medi
47、anof these measurements rounded to the nearest displayed unit ofIRHD (whole numbers for analog instruments and 0.1 units fordigital instruments, if so equipped), and record the result as thehardness value.TABLE 3 Relationship of IRHD and Penetrations DifferencesTypes S1, S2, and Type MNOTETable 3 is
48、 applicable for instruments reading in inches. In Type M micro-hardness, the values are to be multiplied by a factor of 6.IRHDMovementof PlungerIRHDMovement ofPlungerIRHDMovementof PlungerIRHDMovement ofPlungermils mils mils mils28 76.1 47 41.5 66 23.2 85 11.029 73.5 48 40.3 67 22.5 86 10.530 71.0 4
49、9 39.1 68 21.7 87 9.931 68.6 50 38.0 69 21.0 88 9.332 66.4 51 36.8 70 20.3 89 8.833 64.2 52 35.8 71 19.6 90 8.234 62.1 53 34.7 72 18.9 91 7.735 60.1 54 33.7 73 18.3 92 7.136 58.2 55 32.7 74 17.6 93 6.537 56.4 56 31.7 75 17.0 94 5.938 54.7 57 30.8 76 16.3 95 5.339 53.0 58 29.8 77 15.7 96 4.740 51.4 59 28.9 78 15.1 97 4.041 49.8 60 28.1 79 14.5 98 3.342 48.3 61 27.2 80 13.9 99 2.443 46.9 62 26.4 81 13.3 100 0.044 45.5 63 25.5 82 12.745 44.1 64 24.7 83 12.246 42.8 65 24.0 84 11.6TABLE 3 (a) Conversion of values of D to IRHDTypes S1 and S2 (D = different
