ASTM G99-05(2010)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: G99 − 05(Reapproved 2010)
Standard Test Method for
Wear Testing with a Pin-on-Disk Apparatus
ThisstandardisissuedunderthefixeddesignationG99;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope held, is often used as the pin specimen. The test machine
causes either the disk specimen or the pin specimen to revolve
1.1 This test method covers a laboratory procedure for
about the disk center. In either case, the sliding path is a circle
determining the wear of materials during sliding using a
on the disk surface. The plane of the disk may be oriented
pin-on-disk apparatus. Materials are tested in pairs under
either horizontally or vertically.
nominally non-abrasive conditions. The principal areas of
experimental attention in using this type of apparatus to
NOTE 1—Wear results may differ for different orientations.
measure wear are described. The coefficient of friction may
3.1.1 The pin specimen is pressed against the disk at a
also be determined.
specifiedloadusuallybymeansofanarmorleverandattached
1.2 The values stated in SI units are to be regarded as
weights. Other loading methods have been used, such as
standard. No other units of measurement are included in this
hydraulic or pneumatic.
standard.
NOTE 2—Wear results may differ for different loading methods.
1.3 This standard does not purport to address all of the
3.2 Wear results are reported as volume loss in cubic
safety concerns, if any, associated with its use. It is the
millimetres for the pin and the disk separately. When two
responsibility of the user of this standard to establish appro-
different materials are tested, it is recommended that each
priate safety and health practices and determine the applica-
material be tested in both the pin and disk positions.
bility of regulatory limitations prior to use.
3.3 The amount of wear is determined by measuring appro-
2. Referenced Documents
priatelineardimensionsofbothspecimensbeforeandafterthe
2.1 ASTM Standards:
test,orbyweighingbothspecimensbeforeandafterthetest.If
E178Practice for Dealing With Outlying Observations
linear measures of wear are used, the length change or shape
G40Terminology Relating to Wear and Erosion
change of the pin, and the depth or shape change of the disk
G117Guide for Calculating and Reporting Measures of
wear track (in millimetres) are determined by any suitable
Precision Using Data from Interlaboratory Wear or Ero-
metrological technique, such as electronic distance gaging or
sion Tests
stylusprofiling.Linearmeasuresofwearareconvertedtowear
2.2 DIN Standard:
volume (in cubic millimetres) by using appropriate geometric
DIN 50324Testing of Friction and Wear
relations. Linear measures of wear are used frequently in
practicesincemasslossisoftentoosmalltomeasureprecisely.
3. Summary of Test Method
Iflossofmassismeasured,themasslossvalueisconvertedto
3.1 For the pin-on-disk wear test, two specimens are re-
volume loss (in cubic millimetres) using an appropriate value
quired. One, a pin with a radiused tip, is positioned perpen-
for the specimen density.
dicular to the other, usually a flat circular disk. A ball, rigidly
3.4 Wear results are usually obtained by conducting a test
for a selected sliding distance and for selected values of load
and speed. One set of test conditions that was used in an
This test method is under the jurisdiction of ASTM Committee G02 on Wear
and Erosion and is the direct responsibility of Subcommittee G02.40 on Non-
interlaboratory measurement series is given in Table 1 and
Abrasive Wear.
Table 2 as a guide. Other test conditions may be selected
Current edition approved April 1, 2010. Published April 2010. Originally
depending on the purpose of the test.
approved in 1990. Last previous edition approved in 2005 as G99–05. DOI:
10.1520/G0099-05R10.
3.5 Wear results may in some cases be reported as plots of
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
wear volume versus sliding distance using different specimens
contactASTM Customer Service at service@astm.org. ForAnnual Book ofASTM
Standards volume information, refer to the standard’s Document Summary page on
for different distances. Such plots may display non-linear
the ASTM website.
relationships between wear volume and distance over certain
Available from Beuth Verlag GmbH (DIN-- DIN Deutsches Institut fur
portions of the total sliding distance, and linear relationships
Normunge.V.),Burggrafenstrasse6,10787,Berlin,Germany,http://www.en.din.de.
over other portions. Causes for such differing relationships
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
G99 − 05 (2010)
TABLE 1 Characteristics of the Interlaboratory Wear Test Specimens
NOTE 1—See Note 4 for information.
A
Roughness
Composition (weight% ) Microstructure Hardness (HV 10)
R (mean) (µm) R (mean) (µm)
z a
B
Steel ball (100 Cr6) (AISI 52 100) 1.35 to 1.65 Cr martensitic with minor carbides 838 ± 21 0.100 0.010
Diameter 10 mm
← 0.95 to 1.10 C and austenite
0.15 to 0.35 Si
0.25 to 0.45 Mn
C
Steel disc (100 Cr6) (AISI 52 100) ← <0.030 P martensitic with minor carbides 852 ± 14 0.952 0.113
Diameter 40 mm
<0.030 S and austenite
D
Alumina ball, diameter = 10 mm ← 95 %Al O (with addi- equi-granular alpha alumina 1610 ± 101 (HV 0.2) 1.369 0.123
2 3
tives of TiO , with very minor secondary
D
Alumina disc, diameter = 40.6 mm
← MgO, and ZnO) phases 1599 ± 144 (HV 0.2) 0.968 0.041
A
Measured by stylus profilometry. R is maximum peak-to-valley roughness. R is arithmetic average roughness.
z a
B
Standard ball-bearing balls (SKF).
C
Standard spacers for thrust bearings (INA).
D
Manufactured by Compagnie Industrielle des Ceramiques Electroniques, France.
A
TABLE 2 Results of the Interlaboratory Tests
NOTE 1— See Note 4.
NOTE 2—Numbers in parentheses refer to all data received in the tests. In accordance with Practice E178, outlier data values were identified in some
cases and discarded, resulting in the numbers without parentheses. The differences are seen to be small.
NOTE 3—Values preceded by ± are one standard deviation.
NOTE 4—Data were provided by 28 laboratories.
NOTE 5—Calculated quantities (for example, wear volume) are given as mean values only.
NOTE 6—Values labeled “NM” were found to be smaller than the reproducible limit of measurement.
NOTE 7—A similar compilation of test data is given in DIN 50324.
Specimen Pairs
Results (ball) (disk)
Steel-steel Alumina-steel Steel-alumina Alumina-alumina
Ball wear scar diameter (mm) 2.11 ± 0.27 NM 2.08 ± 0.35 0.3± 0.06
(2.11 ± 0.27) (2.03 ± 0.41) (0.3 ± 0.06)
−3 3
Ball wear volume (10 mm ) 198 . 186 0.08
(198) (169) (0.08)
Number of values 102 . 60 56
(102) (64) (59)
Disk wear scar width (mm) NM 0.64 ± 0.12 NM NM
(0.64 ± 0.12)
−3 3
Disk wear volume (10 mm ) . 480 . .
(480)
Number of values . 60 . .
(60)
Friction coefficient 0.60 ± 0.11 0.76 ± 0.14 0.60 ± 0.12 0.41 ± 0.08
Number of values 109 75 64 76
A −1
Test conditions: F=10 N; v=0.1ms , T = 23°C; 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 = α-Al O .
2 3
include initial “break-in” processes, transitions between re- 4. Significance and Use
gions of different dominant wear mechanisms, and so forth.
4.1 The amount of wear in any system will, in general,
Theextentofsuchnon-linearperiodsdependsonthedetailsof
depend upon the number of system factors such as the applied
the test system, materials, and test conditions.
load, machine characteristics, sliding speed, sliding distance,
3.6 It is not recommended that continuous wear depth data the environment, and the material properties.The value of any
obtained from position-sensing gages be used because of the wear test method lies in predicting the relative ranking of
complicatedeffectsofweardebrisandtransferfilmspresentin material combinations. Since the pin-on-disk test method does
the contact gap, and interferences from thermal expansion or not attempt to duplicate all the conditions that may be
contraction. experienced in service (for example; lubrication, load,
G99 − 05 (2010)
due to the sliding friction. The pin holder and arm must be of
substantialconstructiontoreducevibrationalmotionduringthe
test.
5.5 Wear Measuring Systems—Instruments to obtain linear
measures of wear should have a sensitivity of 2.5 µm or better.
Anybalanceusedtomeasurethemasslossofthetestspecimen
shall have a sensitivity of 0.1 mg or better; in low wear
situations greater sensitivity may be needed.
6. Test Specimens and Sample Preparation
6.1 Materials—Thistestmethodmaybeappliedtoavariety
NOTE 1—F is the normal force on the pin, d is the pin or ball diameter,
ofmaterials.Theonlyrequirementisthatspecimenshavingthe
D is the disk diameter, R is the wear track radius, and w is the rotation
specified dimensions can be prepared and that they will
velocity of the disk.
withstand the stresses imposed during the test without failure
FIG. 1 Schematic of Pin-on-Disk Wear Test System
or excessive flexure. The materials being tested shall be
described by dimensions, surface finish, material type, form,
composition,microstructure,processingtreatments,andinden-
pressure, contact geometry, removal of wear debris, and
tation hardness (if appropriate).
presence of corrosive environment), there is no insurance that
the test will predict the wear rate of a given material under
6.2 Test Specimens—Thetypicalpinspecimeniscylindrical
conditions differing from those in the test.
or spherical in shape. Typical cylindrical or spherical pin
specimen diameters range from 2 to 10 mm. The typical disk
5. Apparatus
specimen diameters range from 30 to 100 mm and have a
5.1 General Description—Fig. 1 shows a schematic draw-
thickness in the range of 2 to 10 mm. Specimen dimensions
ing of a typical pin-on-disk wear test system. One type of
used in an interlaboratory test with pin-on-disk systems are
typical system consists of a driven spindle and chuck for
given in Table 1.
holding the revolving disk, a lever-arm device to hold the pin,
6.3 Surface Finish—Aground surface roughness of 0.8 µm
andattachmentstoallowthepinspecimentobeforcedagainst
(32 µin.) arithmetic average or less is usually recommended.
the revolving disk specimen with a controlled load. Another
NOTE 3—Rough surfaces make wear scar measurement difficult.
type of system loads a pin revolving about the disk center
againstastationarydisk.Inanycasetheweartrackonthedisk
6.3.1 Care must be taken in surface preparation to avoid
is a circle, involving multiple wear passes on the same track.
subsurfacedamagethataltersthematerialsignificantly.Special
The system may have a friction force measuring system, for
surfacepreparationmaybeappropriateforsometestprograms.
example,aloadcell,thatallowsthecoefficientoffrictiontobe
State the type of surface and surface preparation in the report.
determined.
7. Test Parameters
5.2 Motor Drive—Avariable speed motor, capable of main-
taining constant speed (61% of rated full load motor speed)
7.1 Load—Values of the force in Newtons at the wearing
under load is required. The motor should be mounted in such
contact.
a manner that its vibration does not affect the test. Rotating
7.2 Speed—The relative sliding speed between the contact-
speeds are typically in the range 0.3 to 3 rad/s (60 to 600
ing surfaces in metres per second.
r/min).
7.3 Distance—The accumulated sliding distance in meters.
5.3 Revolution Counter—The machine shall be equipped
with a revolution counter or its equivalent that will record the
7.4 Temperature—The temperature of one or both speci-
number of disk revolutions, and preferably have the ability to
mens at locations close to the wearing contact.
shutoffthemachineafterapre-selectednumberofrevolutions.
7.5 Atmosphere—The atmosphere (laboratory air, relative
5.4 Pin Specimen Holder and Lever Arm—In one typical
humidity, argon, lubricant, and so forth.) surrounding the
system, the stationary specimen holder is attached to a lever
wearing contact.
armthathasapivot.Addingweights,asoneoptionofloading,
produces a test force proportional to the mass of the weights
8. Procedure
applied. Ideally, the pivot of the arm should be located in the
8.1 Immediately prior to testing, and prior to measuring or
planeofthewearingcontacttoavoidextraneousloadingforces
weighing,cleananddrythespecimens.Takecaretoremoveall
dirt and foreign matter from the specimens. Use non-
chlorinated, non-film-forming cleaning agents and solvents.
A number of other reported designs for pin-on-disk systems are given in “A
Catalog of Friction andWear Devices,”American Society of Lubrication Engineers
Dry materials with open grains to remove all traces of the
(1973). Three commercially-built pin-on-disk machines were either involved in the
cleaning fluids that may be entrapped in the material. Steel
interlaboratory testing for this standard or submitted test data that compared
(ferromagnetic) specimens having residual magnetism should
adequately to the interlaboratory test data. Further information on these machines
can be found in Research Report RR:G02-1008. be demagnetized. Report the methods used for cleaning.
G99 − 05 (2010)
8.2 Measureappropriatespecimendimensionstothenearest ing that assumptions regarding wear of each member may be
2.5 µm or weigh the specimens to the nearest 0.0001 g. required to justify the assumed final geometry.
9.1.3 Wearscarmeasurementsshouldbedoneatleastattwo
8.3 Insert the disk securely in the holding device so that the
representative locations on the pin surfaces and disk surfaces,
disk is fixed perpendicular (61°) to the axis of the resolution.
and the final results averaged.
8.4 Insert the pin specimen securely in its holder and, if
9.1.4 In situations where both the pin and the disk wear
necessary,adjustsothatthespecimenisperpendicular(61°)to
significantly, it will be necessary to measure the wear depth
the disk surface when in contact, in order to maintain the
profile on both members. A suitable method uses stylus
necessary contact conditions.
profiling. Profiling is the only approach to determine the exact
8.5 Add the proper mass to the system lever or bale to final shape of the wear surfaces and thereby to calculate the
volume of material lost due to wear. In the case of disk wear,
develop the selected force pressing the pin against the disk.
the average wear track profile can be in
...