ASTM E384-2011e1 3819 Standard Test Method for Knoop and Vickers Hardness of Materials 《材料的努氏硬度和维氏硬度标准试验方法》.pdf

1、Designation: E384 111Standard Test Method forKnoop and Vickers Hardness of Materials1This standard is issued under the fixed designation E384; 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 p

2、arentheses 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.1NOTESections 8.3 and A1.1.4 were editorially corrected in March 2012.1. Scop

3、e*1.1 This test method covers determination of the Knoop andVickers hardness of materials, the verification of Knoop andVickers hardness testing machines, and the calibration ofstandardized Knoop and Vickers test blocks.1.2 This test method covers Knoop and Vickers hardnesstests made utilizing test

4、forces in micro (9.807 3 10-3to 9.807N)(1to1000 gf ) and macro (9.807 to 1176.80 N) ( 1kgto 120 kgf ) ranges.NOTE 1Previous versions of this standard limited test forces to 9.807N (1 kgf).1.3 This test method includes all of the requirements toperform macro Vickers hardness tests as previously defin

5、ed inTest Method E92, Standard Test Method for Vickers HardnessTesting.1.4 This test method includes an analysis of the possiblesources of errors that can occur during Knoop and Vickerstesting and how these factors affect the accuracy, repeatability,and reproducibility of test results.NOTE 2While Co

6、mmittee E04 is primarily concerned with metals, thetest procedures described are applicable to other materials.1.5 UnitsWhen Knoop and Vickers hardness tests weredeveloped, the force levels were specified in units of grams-force (gf) and kilograms-force (kgf). This standard specifiesthe units of for

7、ce and length in the International System ofUnits (SI); that is, force in Newtons (N) and length in mm orm. However, because of the historical precedent and contin-ued common usage, force values in gf and kgf units areprovided for information and much of the discussion in thisstandard as well as the

8、 method of reporting the test resultsrefers to these units.1.6 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-bi

9、lity of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C1326 Test Method for Knoop Indentation Hardness ofAdvanced CeramicsC1327 Test Method for Vickers Indentation Hardness ofAdvanced CeramicsE3 Guide for Preparation of Metallographic SpecimensE7 Terminology Relating

10、 to MetallographyE29 Practice for Using Significant Digits in Test Data toDetermine Conformance with SpecificationsE74 Practice of Calibration of Force-Measuring Instru-ments for Verifying the Force Indication of Testing Ma-chinesE92 Test Method for Vickers Hardness of Metallic Materi-als3E122 Pract

11、ice for Calculating Sample Size to Estimate,With Specified Precision, the Average for a Characteristicof a Lot or ProcessE140 Hardness Conversion Tables for Metals RelationshipAmong Brinell Hardness, Vickers Hardness, RockwellHardness, Superficial Hardness, Knoop Hardness, andScleroscope HardnessE17

12、5 Terminology of MicroscopyE177 Practice for Use of the Terms Precision and Bias inASTM Test MethodsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE766 Practice for Calibrating the Magnification of a Scan-ning Electron Microscope1This test method is u

13、nder the jurisdiction of ASTM Committee E04 onMetallography and is the direct responsibility of Subcommittee E04.05 on Micro-indentation Hardness Testing.With this revision the test method was expanded toinclude the requirements previously defined in E28.92, Standard Test Method forVickers Hardness

14、Testing of Metallic Material that was under the jurisdiction ofE28.06Current edition approved Aug. 1, 2011. Published August 2011. Originallyapproved in 1969. Last previous edition approved in 2010 as E384 102. DOI:10.1520/E0384-11E01.2For referenced ASTM standards, visit the ASTM website, www.astm.

15、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.3Withdrawn. The last approved version of this historical standard is referencedon www.astm.org.1*A Summary of Changes section

16、appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.2.2 ISO Standards:4ISO 6507-1 Metallic MaterialsVickers hardness TestPart 1: Test MethodISO/IEC 17011 Conformity AssessmentGeneral Require-ments for A

17、ccreditation Bodies Accrediting ConformityAssessment Bodies.ISO/IEC 17025 General Requirements for the Competenceof Testing and Calibration Laboratories3. Terminology3.1 DefinitionsFor the standard definitions of terms usedin this test method, see Terminology E7.3.2 Definitions of Terms Specific to

18、This Standard:3.2.1 calibrating, vdetermining the values of the signifi-cant parameters by comparison with values indicated by areference instrument or by a set of reference standards.3.2.2 Knoop hardness number, HK, nan expression ofhardness obtained by dividing the force applied to the Knoopindent

19、er by the projected area of the permanent indentationmade by the indenter.3.2.3 Knoop indenter, na rhombic-based pyramidal-shaped diamond indenter with edge angles of /A = 172 308and / B = 130 08 (see Fig. 2).3.2.4 microindentation hardness test, na hardness testusing a calibrated machine to force a

20、 diamond indenter ofspecific geometry into the surface of the material beingevaluated, in which the test forces are 9.807 3 10-3to 9.807 N(1 to 1000 gf) and the indentation diagonal, or diagonals aremeasured with a light microscope after load removal; for anytest, it is assumed that the indentation

21、does not undergo elasticrecovery after force removal. The test results are normally inthe Knoop or Vickers scales.3.2.5 macroindention hardness test, na hardness test us-ing a calibrated machine to force an indenter of specificgeometry into the surface of the material being evaluated, inwhich the te

22、st forces are normally higher than 9.807 N (1 kgf).Macroindentation test scales include Vickers, Rockwell andBrinell.NOTE 3Use of the term microhardness should be avoided because itimplies that the hardness, rather than the force or the indentation size, isvery low.3.2.6 verifying, vchecking or test

23、ing the instrument toassure conformance with the specification.3.2.7 Vickers hardness number, HV, nan expression ofhardness obtained by dividing the force applied to a Vickersindenter by the surface area of the permanent indentation madeby the indenter.3.2.8 Vickers indenter, na square-based pyramid

24、al-shapeddiamond indenter with face angles of 136 (see Fig. 1).3.2.9 scale, na specific combination of indenter (Knoopor Vickers) and the test force. For example, HV10 is a scaledefined as using a Vickers indenter and a 10 kgf test force andHK 0.1 is a scale defined as using a Knoop indenter and a 1

25、00gf test force. See 5.8 for the proper reporting of the hardnesslevel and scale.3.3 FormulaeThe formulae presented in 5.5 and 5.6 forcalculating Knoop and Vickers hardness are based upon anideal tester. The measured value of the Knoop and Vickershardness of a material is subject to several sources

26、of errors.Based on Eq 1-9, variations in the applied force, geometricalvariations between diamond indenters, and human errors inmeasuring indentation lengths can affect the calculated mate-rial hardness. The influence each of these parameters has on the4Available from International Organization for

27、Standardization (ISO), 1, ch. dela Voie-Creuse, Case postale 56, CH-1211, Geneva 20, Switzerland, http:/www.iso.org.FIG. 1 Vickers IndenterE384 1112calculated value of a Knoop or Vickers measurement isdiscussed in Section 10.4. Significance and Use4.1 Hardness tests have been found to be very useful

28、 formaterials evaluation, quality control of manufacturing pro-cesses and research and development efforts. Hardness, al-though empirical in nature, can be correlated to tensile strengthfor many metals, and is an indicator of wear resistance andductility.4.2 Microindentation hardness tests extend te

29、sting to mate-rials that are too thin or too small for macroindentationhardness tests. Microindentation hardness tests also allowspecific phases or constituents and regions or gradients toosmall for macroindentation hardness testing to be evaluated.4.3 Because the Knoop and Vickers hardness will rev

30、ealhardness variations that may exist within a material, a singletest value may not be representative of the bulk hardness.4.4 The Vickers indenter usually produces a geometricallysimilar indentation at all test forces. Except for tests at verylow forces that produce indentations with diagonals smal

31、lerthan about 25 m, the hardness number will be essentially thesame as produced by Vickers machines with test forces greaterthan 1 kgf, as long as the material being tested is reasonablyhomogeneous. For isotropic materials, the two diagonals of aVickers indentation are equal in size. Recommendations

32、 forlow force microindentation testing can be found in AppendixX5.4.5 The Knoop indenter does not produce a geometricallysimilar indentation as a function of test force. Consequently,the Knoop hardness will vary with test force. Due to itsrhombic shape, the indentation depth is shallower for a Knoop

33、indentation compared to a Vickers indentation under identicaltest conditions. The two diagonals of a Knoop indentation aremarkedly different. Ideally, the long diagonal is 7.114 timeslonger than the short diagonal, but this ratio is influenced byelastic recovery. Thus, the Knoop indenter is very use

34、ful forevaluating hardness gradients or thin coatings of sectionedsamples.5. Principle of Test5.1 In this test method, a Knoop or Vickers hardness numberis determined based on the formation of a relatively smallindentation made in the test surface of samples being evalu-ated.5.2 A Knoop or Vickers i

35、ndenter, made from diamond ofspecific geometry, is pressed into the test specimen surface byan accurately controlled applied force using test machinesspecifically designed for such work.5.3 Knoop and Vickers hardness testing is divided intomicro and macro-test force ranges as defined:Range Test Forc

36、eMicro 9.807 3 10-3to # 9.807N(1to# 1000 gf)Macro 9.807 to # 1176.80 N ( 1 to # 120 kgf)5.3.1 Knoop scale testing is normally performed usingmicro-range test forces (1kg and less) while the Vickers scaleis used over both the micro and macro-ranges.NOTE 4The user should consult with the manufacturer

37、before apply-ing test forces in the macro-ranges (over 1 kg) with diamond indenterspreviously used for micro-range testing. The diamond mount may not bestrong enough to support the higher test forces and the diamond may notbe large enough to produce the larger indentation sizes.5.4 The size of the i

38、ndentation is measured using a lightmicroscope equipped with a filar type eyepiece, or other typeof measuring device (see Terminology E175). Micro-rangeindents are typically measured in m (micrometers) andmacro-range indents are measured in mm. The formulas forboth units are given below.5.5 The Knoo

39、p hardness number is based upon the forcedivided by the projected area of the indentation5.5.1 For Knoop hardness testing, test loads are typically ingrams-force (gf) and indentation diagonals are in micrometersFIG. 2 Knoop IndenterE384 1113(m). The Knoop hardness number, in terms of gf and m, iscal

40、culated using the following:HK 5 1.000 3 1033 P/Ap! 5 1.000 3 1033 P/cp3 d2! (1)orHK 5 14229 3 P/d2(2)Indenter constant 5 cp5tan/B22 tan/A2(3)where:P = force, gf,d = length of long diagonal, m,Ap= projected area of indentation, m2/A = included longitudinal edge angle, 172 30/B = included transverse

41、edge angle, 130 0 (see Fig. 2and,cp= indenter constant relating projected area of the in-dentation to the square of the length of the longdiagonal, ideally 0.07028.NOTE 5HK values for a 1gf (9.807 3 103N) test force are containedin Appendix X6. To obtain HK values when other test forces areemployed,

42、 multiply the HK value from Table X6.1 for the d value by theactual test force, gf.5.5.2 The Knoop hardness, in terms of kgf and mm, isdetermined as follows:HK 5 14.229 3 P1/d12(4)where:P1= force, kgf, andd1= length of long diagonal, mm.5.5.3 The Knoop hardness reported with units of GPa isdetermine

43、d as follows:HK 5 0.014229 3 P2/d22(5)where:P2= force, N, andd2= length of the long diagonal of the indentation, mm.5.6 The Vickers hardness number is based upon the forcedivided by the surface area of the indentation.5.6.1 For the micro-range Vickers hardness test loads aretypically in grams-force

44、(gf) and indentation diagonals are inmicrometers (m). The Vickers hardness number, in terms of gfand m, is calculated as follows:HV 5 1.000 3 1033 P/As5 2.000 3 1033 P sin a/2!/d2(6)orHV 5 1854.4 3 P/d2(7)where:P = force, gf,As= surface area of the indentation, m2,d = mean diagonal length of the ind

45、entation, m, anda = face angle of the indenter, 136 0 (see Fig. 1).NOTE 6HV numbers for a 1 gf (9.807 3 103N) test load arecontained inAppendix X6. To obtain HV values when other test forces areemployed, multiply the HV value from Table X6.2 for the d value by theactual test force, gf.5.6.2 Macro ra

46、nge Vickers hardness is typically determinedusing kgf and mm and is calculated as follows:HV 5 1.8544 3 P1/d12(8)where:P1= force, kgf, andd1= mean diagonal length of the indentations, mm.5.6.3 The Vickers hardness reported with units of GPa isdetermined as follows:HV 5 0.0018544 3 P2/d22(9)where:P2=

47、 force, N, andd2= mean diagonal length of the indentations, mm.5.7 It is assumed that elastic recovery does not occur whenthe indenter is removed after the loading cycle. That is, it isassumed that the indentation retains the shape of the indenterafter the force is removed. In Knoop testing, it is a

48、ssumed thatthe ratio of the long diagonal to the short diagonal of theindentation is the same as for the indenter.5.8 The symbols HK for Knoop hardness, and HV forVickers hardness shall be used with the reported numericalvalues.5.8.1 For this standard, the hardness test results can bereported in sev

49、eral different ways. For example, if the Knoophardness was found to be 400, and the test force was 100 gf, thetest results may be reported as follows:5.8.1.1 In the kilogram force system: 400 HK 0.1.5.8.1.2 In the gram force system: 400 HK 100 gf.5.8.1.3 In the SI system: 3.92 GPa.5.8.1.4 For nonstandard dwell times, other than 10 to 15 s,the hardness would be reported as 400 HK 0.1 /22. In this case,22 would be the actual time of full load dwell time in seconds.5.9 The reported Knoop and Vickers hardness number shallbe reported