1、Designation: G 133 051Standard Test Method forLinearly Reciprocating Ball-on-Flat Sliding Wear1This standard is issued under the fixed designation G 133; 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 () indicates an editorial change since the last revision or reapproval.1NOTEAdded research report footnote to Section 11 editorially in December 2008.1. Scope1.1 This test method covers laboratory procedures for de-ter
3、mining the sliding wear of ceramics, metals, and othercandidate wear-resistant materials using a linear, reciprocatingball-on-flat plane geometry. The direction of the relativemotion between sliding surfaces reverses in a periodic fashionsuch that the sliding occurs back and forth and in a straightl
4、ine. The principal quantities of interest are the wear volumesof the contacting ball and flat specimen materials; however, thecoefficient of kinetic friction may also be measured using themethod described. This test method encompasses both unlu-bricated and lubricated testing procedures. The scope o
5、f thistest method does not include testing in corrosive or chemicallyaggressive environments.1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.3 This standard does not purport to address all of thesafety concerns, if any, a
6、ssociated 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:2E112 Test Methods for Determining Average Grain SizeE
7、1181 Test Methods for Characterizing Duplex Grain SizesG40 Terminology Relating to Erosion and WearG99 Test Method for Wear Testing with a Pin-on-DiskApparatusG115 Guide for Measuring and Reporting Friction Coeffi-cientsG117 Guide for Calculating and Reporting Measures ofPrecision Using Data from In
8、terlaboratory Wear or Ero-sion TestsG118 Guide for Recommended Format of Wear Test DataSuitable for Databases3. Terminology3.1 DefinitionsDefinitions used in this test method aregiven in Terminology G40. The following definitions ofimportant terms used in this test method are cited fromTerminology G
9、40.3.1.1 friction forcethe resisting force tangential to theinterface between two bodies when, under the action of anexternal force, one body moves or tends to move relative to theother.3.1.2 Hertzian contact pressurethe magnitude of the pres-sure at any specified location in a Hertzian contact area
10、, ascalculated from Hertzs equations of elastic deformation.3.1.3 weardamage to a solid surface, generally involvingthe progressive loss of material due to relative motion betweenthat surface and a contacting surface or surfaces.3.1.4 wear ratethe rate of material removal or dimen-sional change due
11、to wear per unit of exposure parameter, forexample, quantity removed (mass, volume, thickness) in unitdistance of sliding or unit time.4. Summary of Test Method4.1 This test method involves two specimensa flat speci-men and a spherically ended specimen (herein called the “ball”specimen) which slides
12、 against the flat specimen. Thesespecimens move relative to one another in a linear, back andforth sliding motion, under a prescribed set of conditions.4.2 In this test method, the load is applied verticallydownward through the ball specimen against the horizontallymounted flat specimen. The normal
13、load, stroke length, fre-quency and type of oscillation, test temperature, lubricant (ifany), test duration, and atmospheric environment (includingrelative humidity range) are selected from one of two proce-dures.4.3 Since this test method involves reciprocating slidingwhere changes in the sliding v
14、elocity and direction of motionoccur during the test, constant velocity conditions are not1This test method is under the jurisdiction of ASTM Committee G02 on Wearand Erosion and is the direct responsibility of Subcommittee G02.40 on Non-Abrasive Wear.Current edition approved May 1, 2005. Published
15、May 2005. Originallyapproved in 1995. Last previous edition approved in 2002 as G 133 02.2For referenced ASTM standards, 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 Summ
16、ary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.maintained. The manner in which the velocity varies with timeis determined by the design of the mechanism which drives theball or flat specimen back and fort
17、h.4.4 Dimensional changes for both ball and flat specimensare used to calculate wear volumes and wear rates.4.5 Friction forces are measured during the test and may beused to assess changes in the contact conditions or the kineticfriction coefficient as a function of time.5. Significance and Use5.1
18、This test method is designed to simulate the geometryand motions that are experienced in many types of rubbingcomponents whose normal operation results in periodic rever-sals in the direction of relative sliding. The wear resulting fromthis mode of movement may differ from that experienced bythe sam
19、e materials sliding continuously in only one direction(unidirectional sliding) even for comparable durations ofcontact. Test loads and speeds are to be determined by theseverity of the proposed application or purpose of the testing.Either of two sets of testing conditions (designated ProceduresA and
20、 B) may be used.6. Apparatus6.1 General DescriptionFig. 1 shows the arrangement forthe reciprocating ball-on-flat wear test available on a commer-cial machine. The ball is rigidly mounted and has a sphericaltip which moves back and forth across the surface of a polishedflat specimen. Use of a spheri
21、cal tip alleviates the alignmentproblems associated with flat-ended balls sliding on flat sur-faces. Alternate configurations in which the flat moves and theball specimen is fixed may be used. A provision is made forapplying a uniform normal force (load) to the contact betweenthe ball and the flat.
22、Temperature measurement and controlcapability is provided to heat and monitor the flat specimenwhich may either be immersed in a lubricant bath or testedwithout lubricant. The tangential force can be measuredcontinuously during oscillating contact and used to obtainfriction coefficient data.36.2 Spe
23、cimen DriveA drive train, capable of providingsmooth, reciprocating motion to the ball and overcoming thefrictional resistance of the specimens at maximum load, isrequired. For example, a Scotch yoke drive mechanism canprovide a smooth, sinusoidal velocity profile for the ballspecimen relative to th
24、e flat specimen without the need for themotor to stop and reverse direction periodically. Stepper-typemotors may also be used provided that the motion is smoothand uniform.6.3 Ball and Ball Specimen HolderThe ball specimenmay be a fixed bearing ball or any spherically tipped specimenas long as the s
25、liding contact is equivalent to a ball on a flatplane. If a bearing ball is used, it shall be clamped tightlyenough to prevent slippage during the test. The ball holdershould be rigid enough so that the periodic reversal in thesliding direction does not result in tilting or other misalignmentof the
26、contact.6.4 Flat Specimen HolderThe flat specimen is secured tothe base of the machine to prevent slippage or buckling duringthe test. A variety of shapes and configurations for the flatspecimen are possible. The primary criterion is that the couponpresent a flat, horizontal surface to the ball spec
27、imen.3Machines of this type are described in A Catalogue of Friction and WearDevices, American Society of Lubrication Engineers (now STLE) 838 BusseHighway, Park Ridge, IL, 1973, pp. 5072.FIG. 1 Reciprocating TestSchematic DiagramG13305126.5 Instrumentation:6.5.1 Friction ForceA tension-compression
28、load cell orsimilar force-sensing device may be used to measure thefriction forces generated during sliding. Calibration of thefriction force (see subsection 7.1.3) in both forward and reversesliding directions is required. Since the direction of the frictionforce changes rapidly during the test, tr
29、aditional strip-chart-type recorders may be too slow to follow these changes at highfrequencies of reciprocation. A commercial version of thismachine is available with a signal conditioner to rectify, andoutput the root-mean-square friction force to a strip-chart-recorder or to a computerized data a
30、cquisition system. Themethod of sensing and recording friction force during the testshall be described in the testing report.6.5.2 Test DurationIn this test method, test duration isspecified in seconds. To compute the sliding distance in metresor number of cycles, use the following:X 5 0.002 3 t 3 f
31、 3 L (1)orN 5 t 3 f (2)where:X = total sliding distance of the ball, m,N = number of cycles in the test,t = test time, s,f = oscillating frequency, Hz (cycles/s), andL = length of stroke, mm.A cycle is defined as two stroke lengths (up and back).Electronic timers can be used to terminate the test. I
32、f acycle-counter is available, this may be used instead of thetimer, in which case Eq 2 will be used.6.5.3 HumidityThe wear and friction of many materials issignificantly affected by the moisture in the air. It is thereforerequired that the relative humidity (to an accuracy of 63%)bemeasured before
33、and during the test. Humidity can vary withair flow and in different parts of the same room, so thehumidity sensor should be located as close to the test speci-mens as reasonably possible, in such a way that the airmovement conditions are the same for humidity sensor as forthe test specimens.6.5.4 T
34、emperatureThe ambient temperature, in degreesCelsius, shall be measured and reported during room tempera-ture tests. In full immersion, liquid-lubricated tests, the bathtemperature shall be measured and reported.7. Calibration7.1 The parts of the apparatus that require calibration are(1) the loading
35、 system, (2) the motion drive (speed and strokelength), and (3) the friction force sensor.7.1.1 Loading SystemThe load (normal force) applied tothe specimen shall be checked periodically. In machines whichapply the load by a spring/lever arrangement and indicate theload on a dial gage, this can be d
36、one by substituting apreviously calibrated compression load cell for the specimenand checking the applied load indicated on the loading dialagainst the calibrated load cell output. Statically applied loadsshall be kept constant within a maximum deviation of 62.0 %of the test load. For example, permi
37、tted static error of a 25.0-Nnormal force would be 60.5 N. During oscillating tests, thenormal force may vary slightly about the mean value due to thedynamics of the machine. This variation is to be expected.7.1.2 Motion DriveThe oscillating frequency of the mov-ing specimen shall be checked periodi
38、cally against the drivemotor setting to ensure that the rate of oscillation is known.(WarningDue to inertial effects, differences in the loadingand fixturing method become more significant as the oscillatingfrequency of the test is increased, and harmonic frequenciescharacteristic of the test machin
39、e must be avoided whenselecting the oscillating frequency.)7.1.3 Friction Force SensorThe friction force sensor shallbe calibrated periodically in both directions of load application.Depending on the machine, a fixture which applies a calibrat-ing load in line with the normal point of contact betwee
40、n theball and flat should be used.8. Procedure8.1 Specimen PreparationThe ball specimen and flatspecimen shall be used either in a polished condition, or in aspecified condition consistent with the application of interest.In a polished condition, the surface should be as free aspossible from prepara
41、tion artifacts such as grinding-inducedcracks, gross grinding marks, and grain pull-out. Surfaceroughnesses of 0.02 to 0.05-m Ra(arithmetic roughness) aretypical.8.2 Clean the specimens using the following procedure:8.2.1 Wash with a mild liquid laboratory glassware cleaner,8.2.2 Hot air dry,8.2.3 U
42、ltrasonically clean in acetone (2 min),8.2.4 Hot air dry,8.2.5 Ultrasonically clean in methanol (2 min), and8.2.6 Hot air dry.8.2.7 If there is considerable porosity in the specimens, it isnecessary that they be baked dry for4hatatemperaturegreater than 150C in a clean oven.NOTE 1Certain materials c
43、ould be adversely affected by cleaning insolvents. Deviations from the prescribed cleaning procedure are permitted,but they shall be described in the report.8.3 Clean the specimens after they are secured in place inthe test fixture by wiping with acetone and then with methanol-moistened cotton swabs
44、. It is possible that during mounting,some contamination was inadvertently placed on them, and thisfinal cleaning will help alleviate the problem. Inspect the balltip with a hand lens after it is mounted to ensure that there areno defects in the contact area.8.4 Gently lower the ball specimen upon t
45、he flat specimen,and ensure that the reciprocating drive shaft motion is hori-zontal and parallel to the surface of the flat specimen. Theheight of the specimen or mount may require adjustment toensure that this condition is fulfilled. Apply the prescribed testload. Confirm that the desired oscillat
46、ing speed has been setbefore turning on the motor.8.5 Two possible testing procedures, one for unlubricatedtests (Procedure A), and one for high-contact stress-lubricatedtests at elevated temperature (Procedure B), are given in 8.5.1.The procedure appropriate for the given materials and testseverity
47、 should be selected. If neither procedure in 8.5.1 isG1330513determined to be suitable, other conditions may be used, buttesting will not be in compliance with this test method. See thereporting requirements in 10 for reporting exceptions toProcedures A and B.8.5.1 The two testing procedures are as
48、follows.8.5.1.1 Procedure AUnlubricated wear testing at roomtemperature.(1) Pin tip radius, 4.76 mm (316 in.),(2) Normal force, 25.0 N,(3) Stroke length, 10.0 mm,(4) Oscillating frequency, 5.0 Hz,(5) Test duration, 16 min 40 s (sliding distance 100 m),(6) Ambient temperature, 22 6 3C,(7) Relative hu
49、midity, 40 to 60 %, and(8) Lubrication, none applied.8.5.1.2 Procedure BLubricated wear testing at elevatedtemperature.(1) Pin tip radius, 4.76 mm (316 in.),(2) Normal force, 200.0 N,(3) Stroke length, 10.0 mm,(4) Oscillating frequency, 10.0 Hz,(5) Test duration, 33 min 20 s (sliding distance 400 m),(6) Temperature, 150 6 2C,(7) Relative humidity, 40 to 60 %, and(8) Lubrication, full immersion under the selected lubri-cant (see Note 2).NOTE 2This procedure requires full-immersion lubrication. If othermethods, such a controlled drip feeding system
