1、Designation: G 99 05Standard Test Method forWear Testing with a Pin-on-Disk Apparatus1This standard is issued under the fixed designation G 99; the number immediately following the designation indicates the year of originaladoption or, in the case of revision, the year of last revision.Anumber in pa
2、rentheses indicates the year of last reapproval.Asuperscriptepsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers a laboratory procedure fordetermining the wear of materials during sliding using apin-on-disk apparatus. Materials are teste
3、d in pairs undernominally non-abrasive conditions. The principal areas ofexperimental attention in using this type of apparatus tomeasure wear are described. The coefficient of friction mayalso be determined.1.2 The values stated in SI units are to be regarded asstandard.1.3 This standard does not p
4、urport 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 prior to use.2. Referenced Documents2.1 ASTM Standards:2
5、E 178 Practice for Dealing with Outlying ObservationsG40 Terminology Relating to Wear and ErosionG117 Guide for Calculating and Reporting Measures ofPrecision using Data from Interlaboratory Wear or ErosionTests2.2 Other Standard:3DIN-50324 Testing of Friction and Wear3. Summary of Test Method3.1 Fo
6、r the pin-on-disk wear test, two specimens are re-quired. One, a pin with a radiused tip, is positioned perpen-dicular to the other, usually a flat circular disk. A ball, rigidlyheld, is often used as the pin specimen. The test machinecauses either the disk specimen or the pin specimen to revolveabo
7、ut the disk center. In either case, the sliding path is a circleon the disk surface. The plane of the disk may be orientedeither horizontally or vertically.NOTE 1Wear results may differ for different orientations.3.1.1 The pin specimen is pressed against the disk at aspecified load usually by means
8、of an arm or lever and attachedweights. Other loading methods have been used, such ashydraulic or pneumatic.NOTE 2Wear results may differ for different loading methods.3.2 Wear results are reported as volume loss in cubicmillimetres for the pin and the disk separately. When twodifferent materials ar
9、e tested, it is recommended that eachmaterial be tested in both the pin and disk positions.3.3 The amount of wear is determined by measuring appro-priate linear dimensions of both specimens before and after thetest, or by weighing both specimens before and after the test. Iflinear measures of wear a
10、re used, the length change or shapechange of the pin, and the depth or shape change of the diskwear track (in millimetres) are determined by any suitablemetrological technique, such as electronic distance gaging orstylus profiling. Linear measures of wear are converted to wearvolume (in cubic millim
11、etres) by using appropriate geometricrelations. Linear measures of wear are used frequently inpractice since mass loss is often too small to measure precisely.If loss of mass is measured, the mass loss value is converted tovolume loss (in cubic millimetres) using an appropriate valuefor the specimen
12、 density.3.4 Wear results are usually obtained by conducting a testfor a selected sliding distance and for selected values of loadand speed. One set of test conditions that was used in aninterlaboratory measurement series is given in Table 1 andTable 2 as a guide. Other test conditions may be select
13、eddepending on the purpose of the test.3.5 Wear results may in some cases be reported as plots ofwear volume versus sliding distance using different specimensfor different distances. Such plots may display non-linearrelationships between wear volume and distance over certainportions of the total sli
14、ding distance, and linear relationshipsover other portions. Causes for such differing relationshipsinclude initial “break-in” processes, transitions between re-gions of different dominant wear mechanisms, and so forth.1This test method is under the jurisdiction of ASTM Committee G02 on Wearand Erosi
15、on and is the direct responsibility of Subcommittee G02.40 on Non-Abrasive Wear.Current edition approved May 1, 2005. Published May 2005. Originallyapproved in 1990. Last previous edition approved in 2004 as G 99 04a.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact AST
16、M Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Available from Beuth Verlag GmbH, Burggrafenstrasse 6, 1000 Berlin 30,Germany.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700
17、, West Conshohocken, PA 19428-2959, United States.The extent of such non-linear periods depends on the details ofthe test system, materials, and test conditions.3.6 It is not recommended that continuous wear depth dataobtained from position-sensing gages be used because of thecomplicated effects of
18、wear debris and transfer films present inthe contact gap, and interferences from thermal expansion orcontraction.4. Significance and Use4.1 The amount of wear in any system will, in general,depend upon the number of system factors such as the appliedload, machine characteristics, sliding speed, slid
19、ing distance,the environment, and the material properties. The value of anywear test method lies in predicting the relative ranking ofmaterial combinations. Since the pin-on-disk test method doesnot attempt to duplicate all the conditions that may beexperienced in service (for example; lubrication,
20、load, pres-sure, contact geometry, removal of wear debris, and presenceof corrosive environment), there is no insurance that the testwill predict the wear rate of a given material under conditionsdiffering from those in the test.5. Apparatus5.1 General DescriptionFig. 1 shows a schematic draw-ing of
21、 a typical pin-on-disk wear test system.4One type oftypical system consists of a driven spindle and chuck forholding the revolving disk, a lever-arm device to hold the pin,4A number of other reported designs for pin-on-disk systems are given in “ACatalog of Friction and Wear Devices,” American Socie
22、ty of Lubrication Engineers(1973). Three commercially-built pin-on-disk machines were either involved in theinterlaboratory testing for this standard or submitted test data that comparedadequately to the interlaboratory test data. Further information on these machinescan be found in Research Report
23、RR: G021008.TABLE 1 Characteristics of the Interlaboratory Wear Test SpecimensNOTESee Note 4 in 10.3.1 for information.Composition (weight% ) Microstructure Hardness (HV 10)RoughnessARz(mean) (m) Ra(mean) (m)Steel ball (100 Cr6) (AISI 52 100)BDiameter 10 mm 1.35 to 1.65 Cr0.95 to 1.10 C0.15 to 0.35
24、Si0.25 to 0.45 Mnmartensitic with minor carbidesand austenite838 6 21 0.100 0.010Steel disc (100 Cr6) (AISI 52 100)CDiameter 40 mm 0.030 P0.030 Smartensitic with minor carbidesand austenite852 6 14 0.952 0.113Alumina ball, diameter = 10 mmDAlumina disc, diameter = 40.6 mmD95%Al2O3(with addi-tives of
25、 TiO2,MgO, and ZnO)equi-granular alpha aluminawith very minor secondaryphases1610 6 101 (HV 0.2)1599 6 144 (HV 0.2)1.3690.9680.1230.041AMeasured by stylus profilometry. Rzis maximum peak-to-valley roughness. Rais arithmetic average roughness.BStandard ball-bearing balls (SKF).CStandard spacers for t
26、hrust bearings (INA).DManufactured by Compagnie Industrielle des Ceramiques Electroniques, France.TABLE 2 Results of the Interlaboratory TestsANOTE 1 See Note 4 in 10.3.1.NOTE 2Numbers in parentheses refer to all data received in the tests. In accordance with Practice E 178, outlier data values were
27、 identified in somecases and discarded, resulting in the numbers without parentheses. The differences are seen to be small.NOTE 3Values preceded by 6 are one standard deviation.NOTE 4Data were provided by 28 laboratories.NOTE 5Calculated quantities (for example, wear volume) are given as mean values
28、 only.NOTE 6Values labeled “NM” were found to be smaller than the reproducible limit of measurement.NOTE 7A similar compilation of test data is given in DIN50324.Results (ball) (disk)Specimen PairsSteel-steel Alumina-steel Steel-alumina Alumina-aluminaBall wear scar diameter(mm)2.11 6 0.27(2.11 6 0.
29、27)NM 2.08 6 0.35(2.03 6 0.41)0.36 0.06(0.3 6 0.06)Ball wear volume (103mm3)198(198). 186(169)0.08(0.08)Number of values 102(102). 60(64)56(59)Disk wear scar width (mm) NM 0.64 6 0.12(0.64 6 0.12)NM NMDisk wear volume (103mm3). 480(480). .Number of values . 60(60). .Friction coefficient 0.60 6 0.11
30、0.76 6 0.14 0.60 6 0.12 0.41 6 0.08Number of values 109 75 64 76ATest conditions: F =10N; v =0.1ms1, T = 23C; relative humidity range 12 to 78 %; laboratory air; sliding distance 1000 m; wear track (nominal) diameter = 32 mm;materials: steel = AISI 52 100; and alumina = a-Al2O3.G99052and attachments
31、 to allow the pin specimen to be forced againstthe revolving disk specimen with a controlled load. Anothertype of system loads a pin revolving about the disk centeragainst a stationary disk. In any case the wear track on the diskis a circle, involving multiple wear passes on thesame track. The syste
32、m may have a friction force measuringsystem, for example, a load cell, that allows the coefficient offriction to be determined.5.2 Motor DriveAvariable speed motor, capable of main-taining constant speed (61 % of rated full load motor speed)under load is required. The motor should be mounted in such
33、a manner that its vibration does not affect the test. Rotatingspeeds are typically in the range 0.3 to 3 rad/s (60 to 600r/min).5.3 Revolution CounterThe machine shall be equippedwith a revolution counter or its equivalent that will record thenumber of disk revolutions, and preferably have the abili
34、ty toshut off the machine after a pre-selected number of revolutions.5.4 Pin Specimen Holder and Lever ArmIn one typicalsystem, the stationary specimen holder is attached to a leverarm that has a pivot.Adding weights, as one option of loading,produces a test force proportional to the mass of the wei
35、ghtsapplied. Ideally, the pivot of the arm should be located in theplane of the wearing contact to avoid extraneous loading forcesdue to the sliding friction. The pin holder and arm must be ofsubstantial construction to reduce vibrational motion during thetest.5.5 Wear Measuring SystemsInstruments t
36、o obtain linearmeasures of wear should have a sensitivity of 2.5 m or better.Any balance used to measure the mass loss of the test specimenshall have a sensitivity of 0.1 mg or better; in low wearsituations greater sensitivity may be needed.6. Test Specimens and Sample Preparation6.1 MaterialsThis t
37、est method may be applied to a varietyof materials.The only requirement is that specimens having thespecified dimensions can be prepared and that they willwithstand the stresses imposed during the test without failureor excessive flexure. The materials being tested shall bedescribed by dimensions, s
38、urface finish, material type, form,composition, microstructure, processing treatments, and inden-tation hardness (if appropriate).6.2 Test SpecimensThe typical pin specimen is cylindricalor spherical in shape. Typical cylindrical or spherical pinspecimen diameters range from 2 to 10 mm. The typical
39、diskspecimen diameters range from 30 to 100 mm and have athickness in the range of 2 to 10 mm. Specimen dimensionsused in an interlaboratory test with pin-on-disk systems aregiven in Table 1.6.3 Surface FinishA ground surface roughness of 0.8 m(32 in.) arithmetic average or less is usually recommend
40、ed.NOTE 3Rough surfaces make wear scar measurement difficult.6.3.1 Care must be taken in surface preparation to avoidsubsurface damage that alters the material significantly. Specialsurface preparation may be appropriate for some test programs.State the type of surface and surface preparation in the
41、 report.7. Test Parameters7.1 LoadValues of the force in Newtons at the wearingcontact.7.2 SpeedThe relative sliding speed between the contact-ing surfaces in metres per second.7.3 DistanceThe accumulated sliding distance in meters.7.4 TemperatureThe temperature of one or both speci-mens at location
42、s close to the wearing contact.7.5 AtmosphereThe atmosphere (laboratory air, relativehumidity, argon, lubricant, and so forth.) surrounding thewearing contact.8. Procedure8.1 Immediately prior to testing, and prior to measuring orweighing, clean and dry the specimens. Take care to remove alldirt and
43、 foreign matter from the specimens. Use non-chlorinated, non-film-forming cleaning agents and solvents.Dry materials with open grains to remove all traces of thecleaning fluids that may be entrapped in the material. Steel(ferromagnetic) specimens having residual magnetism shouldbe demagnetized. Repo
44、rt the methods used for cleaning.8.2 Measure appropriate specimen dimensions to the nearest2.5 m or weigh the specimens to the nearest 0.0001 g.8.3 Insert the disk securely in the holding device so that thedisk is fixed perpendicular (61) to the axis of the resolution.8.4 Insert the pin specimen sec
45、urely in its holder and, ifnecessary, adjust so that the specimen is perpendicular (61) toNOTEF is the normal force on the pin, d is the pin or ball diameter, D is the disk diameter, R is the wear track radius, and w is the rotation velocityof the disk.FIG. 1 Schematic of pin-on-disk wear test syste
46、m.G99053the disk surface when in contact, in order to maintain thenecessary contact conditions.8.5 Add the proper mass to the system lever or bale todevelop the selected force pressing the pin against the disk.8.6 Start the motor and adjust the speed to the desired valuewhile holding the pin specime
47、n out of contact with the disk.Stop the motor.8.7 Set the revolution counter (or equivalent) to the desirednumber of revolutions.8.8 Begin the test with the specimens in contact under load.The test is stopped when the desired number of revolutions isachieved. Tests should not be interrupted or resta
48、rted.8.9 Remove the specimens and clean off any loose weardebris. Note the existence of features on or near the wear scarsuch as: protrusions, displaced metal, discoloration, microc-racking, or spotting.8.10 Remeasure the specimen dimensions to the nearest 2.5m or reweigh the specimens to the neares
49、t 0.0001 g, asappropriate.8.11 Repeat the test with additional specimens to obtainsufficient data for statistically significant results.9. Calculation and Reporting9.1 The wear measurements should be reported as thevolume loss in cubic millimetres for the pin and disk, sepa-rately.9.1.1 Use the following equations for calculating volumelosses when the pin has initially a spherical end shape of radiusR and the disk is initially flat, under the conditions that onlyone of the two members wears significantly:pin spherical end! volume loss, mm3
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