1、Designation: D5183 05 (Reapproved 2016)Standard Test Method forDetermination of the Coefficient of Friction of LubricantsUsing the Four-Ball Wear Test Machine1This standard is issued under the fixed designation D5183; the number immediately following the designation indicates the year oforiginal ado
2、ption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers a procedure for determining thecoefficient of f
3、riction by means of the Four-Ball Wear TestMachine.21.2 The values stated in either SI units or in the formercm-kgf metric units are to be regarded separately as thestandard. Within the text the cm-kgf units are shown inparentheses. The values stated in each system are not exactequivalents, therefor
4、e each system must be used independentlyof the other. Combining values from the two systems can resultin nonconformance to specification.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 e
5、stablish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. Specific warningstatements are given in 7.3 7.6.2. Referenced Documents2.1 ASTM Standards:3D4172 Test Method for Wear Preventive Characteristics ofLubricating Fluid (Four-Ball M
6、ethod)2.2 ANSI Standard:4B3.12 Specification for Metal Balls3. Terminology3.1 Definitions:3.1.1 coeffcient of friction, ()the ratio of the tangentialforce that is needed to start or to maintain uniform relativemotion between two contacting surfaces to the perpendicularforce holding them in contact.4
7、. Summary of Test Method4.1 Three 12.7 mm (0.5 in.) diameter steel balls are clampedtogether and covered with 10 mL of the wear-in lubricant. Afourth 12.7 mm diameter ball, referred to as the “top ball” ispressed with a force of 392 N (40 kgf) into the cavity formedby the three clamped balls for thr
8、ee-point contact. The tem-perature of the wear-in lubricant is regulated at 75 C (167 F),and then, the top ball is rotated at 600 r min for 60 min.4.2 Fluid is discarded and balls cleaned. The wear scardiameter on each of the lower three balls is examined. If thewear scars average 0.67 mm 6 0.03 mm,
9、 (0.026 in. 60.001 in.) then the 10 mL of test fluid is added to the ball cupwith the worn-in test balls in place. The temperature of the testlubricant is regulated at 75 C (167 F) and the top ball isrotated at 600 r min at 98.1 N (10 kgf) for 10 min.4.3 The load is then increased by 98.1 N (10 kgf)
10、 at the endof each successive 10 min interval up to the point where thefrictional trace indicates incipient seizure. The coefficient offriction is measured at the end of each 10 min interval.5. Significance and Use5.1 This test method can be used to determine the coefficientof friction of lubricatin
11、g fluids under the prescribed test1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.L0.11 on Tribological Properties of Industrial Fluids andLubricates.Current edition approved July
12、 1, 2016. Published July 2016. Originally approvedin 1991. Last previous edition approved in 2011 as D5183 05 (2011). DOI:10.1520/D5183-05R16.2The sole source of supply of the Four-Ball Wear Test Machine known to thecommittee at this time is Falex Corp., 1020 Airpark Dr., Sugar Grove, IL 60554. Ifyo
13、u are aware of alternative suppliers, please provide this information to ASTMInternational Headquarters. Your comments will receive careful consideration at ameeting of the responsible technical committee,1which you may attend.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orc
14、ontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.4Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.Copyrig
15、ht ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1conditions. The user of this test method should determine to hisown satisfaction whether results of this test method correlatewith field performance or other bench test machines.6. Apparatus6.1
16、 Four-Ball Test Machine5See Figs. 1-3.NOTE 1It is important to distinguish between the Four-Ball E.P. andthe Four-Ball Wear Test Machine (see Test Method D4172). The Four-BallE.P. Test Machine is designed for testing under heavier loads and lacks thesensitivity necessary for wear tests.6.2 Microscop
17、e,5capable of measuring the diameters of thescars produced on the three balls to an accuracy of 0.01 mmwithout removal from the ball test cup.6.3 Test Balls, chrome alloy steel, made from AISI StandardSteel No. E-52100, with diameter of 12.7 mm (0.5 in.) Grade25 EP (extra polish). Such balls are des
18、cribed in ANSISpecifications B3.12. The extra-polish finish is not described inthat specification. The Rockwell C hardness shall be 64 to 66,a closer limit than is found in the ANSI requirement.7. Reagents and Materials7.1 Purity of ReagentsReagent grade chemicals shall beused in all tests. Unless o
19、therwise indicated, it is intended thatall reagents conform to the specifications of the Committee onAnalytical Reagents of the American Chemical Society wheresuch specifications are available.6Other grades may be used,provided it is first ascertained that the reagent is of sufficientlyhigh purity t
20、o permit its use without lessening the accuracy ofthe determination.7.2 Wear-In Lubricant, white oil having a viscosity at 40 Cof 24.3 cSt to 26.1 cSt (100 F of 125/135 SUS). It should bepercolated through activated alumina to remove any residualimpurities.7.3 Acetone(WarningFlammable. Health hazard
21、.)7.4 n-Heptane(WarningFlammable. Health hazard.)7.5 Methyl ethyl ketone(WarningFlammable. Healthhazard.)7.6 Pyridine(WarningFlammable. Health hazard.)8. Preparation of Apparatus8.1 Set up the drive of the machine to obtain a spindle speedof 600 r min 6 30 r min.8.2 Set temperature regulator to prod
22、uce a test-oil tempera-ture of 75 C 6 2 C (167 F 6 4 F).8.3 If an automatic timer is used to terminate a test, it shouldbe checked for the required 61 min accuracy at 60 min elapsedtime, and 610 s at 10 min elapsed time.8.4 The loading mechanism should be balanced to a zeroreading with all parts and
23、 test oil in place. To demonstrateproper precision an addition or subtraction of 2.0 N (0.2 kgf)should be detectable in imbalance. Determination of accuracyof loading at 147 N and 392 N (1 kgf5 and 40 kgf) is difficultand generally limited to careful measurement of lever-armratios and weights or pis
24、ton diameter and pressure gaugecalibration.NOTE 2Because of differences in the construction of the variousmachines on which the four-ball can be made, the manufacturersinstructions should be consulted for proper machine set up and operation.9. Conditioning9.1 Test ConditionsSee Table 1.5The Four-Bal
25、l Wear Test Machine and the Falex Multi-Specimen Friction andWear Test Machine, both made by Falex Corp., 1020 Airpark Dr., Sugar Grove, IL60554 have been found satisfactory for this purpose. This company can also furnisha microscope with a special base to measure the wear scars without removing the
26、balls from the test-oil cup. Discontinued models of the Four-Ball Wear Test Machinemade by Precision Scientific Co. and Roxana Machine Works are also satisfactory.6Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For Suggestions on the testing of
27、 reagents notlisted by the American Chemical Society, see Annual Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.FIG. 1 Schematic of a Four-Ball Wear Test MachineFIG.
28、2 Falex VariableSpeed Four-Ball Wear Test MachineD5183 05 (2016)210. Procedure10.1 Thoroughly clean four test balls, clamping parts forupper and lower balls and the ball cup by first soaking inheptane for 1 min and then with sonic agitation for 10 s. Drainand rinse with fresh heptane.10.1.1 Repeat 1
29、0.1 using acetone. Blow dry under a streamof nitrogen gas. After cleaning, handle all parts using only afresh wipe. No trace of solvent should remain when wear-inlubricant is introduced and the machine assembled.10.2 Tighten one of the clean balls into the spindle of thetest machine.10.3 Assemble th
30、ree of the clean balls in the test-oil cup.10.4 Pour the wear-in lubricant indicated in 7.2 into thetest-oil cup to a level at least 3 mm (18 in.) above the top of theballs. Observe that this oil level still exists after the lubricantfills all of the voids in the test oil cup assembly.10.5 Install t
31、he test-oil cup/three balls in the machine andavoid shock loading by slowly applying the test load 392 N(40 kgf).10.6 Turn on the heaters and set controls to obtain 75 C 62 C (167 F 6 4 F). Heater voltage or offset on proportionalcontrollers should be capable of bringing stabilized tempera-ture with
32、in the prescribed limits.10.7 When the test temperature is reached, start the drivemotor that was previously set to drive the top ball at 600 r min6 30 r min. Machines with automatic start using a propor-tional controller will start below the set temperature. Set theproportional band so that test ma
33、chines start at temperatures2 C (4 F) below the set point temperature.10.8 After the drive motor has been on for 60 min 6 1 min,turn off the heaters and drive motor and remove the test-oil cupand three-ball assembly.10.9 Measure the wear scars on the three lower balls to anaccuracy of 60.01 mm by th
34、e following method described in10.10.10.10 Drain the test oil from the three-ball assembly andwipe the scar area with a tissue. Leave the three ballsclamped and set the assembly on a special base of a micro-scope that has been designed for the purpose. Make twoFIG. 3 Falex Multi-Specimen Friction an
35、d Wear Test MachineTABLE 1 Test ConditionsWear-In TestTemperature 75 C 2 C(167 F 4 F)75 C 2 C(167 F 4 F)Speed 600 r/min 600 r/minDuration 60 min 10 minLoad 392 N (40 kgf) per 60 min 98.1 N (10 kgf) per 10 minincrement to a load thatindicates incipient seizure(sudden increase in frictionforce value o
36、ver steady state)on the friction traceD5183 05 (2016)3measurements on each of the wear scars. Take one measure-ment of the scar along a radial line from the center of theholder. Take the second measurement along a line 90 from thefirst measurement. If a scar is elliptical take one measurementwith th
37、e striations and the other across the striations. Take careto ensure that the line of sight is perpendicular to the surfacebeing measured.Average the six readings and report as wear-inscar diameter in millimetres. If the wear-in scar measures0.67 mm 6 0.03 mm, the following test sequence is per-form
38、ed; otherwise, the wear-in sequence is repeated using newspecimen balls. (The wear-in scar can measure outside thisrange in different machines, but for a given machine, repeatedresult should be 60.03 mm. The user should first determine thewear-in average for the machine.)10.11 Add heptane to test-cu
39、p and let soak for 1 min withoccasional agitation. Drain off heptane. Rinse inside of the cupwith heptane using a squeeze bottle to remove entrained oil.Repeat soak and rinse stages twice. Rinse inside of the cupwith two successive rinses of acetone using a squeeze bottle.Blow dry with nitrogen.10.1
40、2 Wipe surface of top ball and entire surface of ballchuck assembly using a clean tissue dampened with heptane.Repeat with a tissue dampened with acetone. Blow dry withnitrogen.10.13 Wipe wear scars on the bottom three balls and weartrack on the top ball with a tissue dampened with methyl ethylketon
41、e.10.14 Pour the sample to be tested into the clean test oil cupassembly, containing the worn-in test balls, to a level at least3mm(18 in.) above the top of the balls. Observe that this oillevel exists after the lubricant fills all of the voids in the test-oilcup assembly.10.15 Install the test-oil
42、cup containing three balls in themachine and avoid shock loading by slowly applying a testload of 98.1 N (10 kgf).10.16 Turn on the heater and set controls to obtain 75 C 62 C (167 F 6 4 F).10.17 When the test temperature is reached, start the drivemotor that was previously set to drive the top ball
43、 at 600 r min6 30 r min. Run for 10 min. Do not allow test machine to stop.At the end of the 10 min interval, record the torque value.Increase the load 98.1 N (10 kgf) every 10 min until thefriction trace indicates incipient seizure is occurring. Recordthe torque value at the end of each 10 min inte
44、rval.10.18 Measure the final wear scars on the three lower ballsto an accuracy of 0.01 mm as described in 10.10 and note theappearance of the wear scar.11. Calculation11.1 Determine the coefficient of friction using one of thetwo following equations: 5 0.00223 fL/P (1)where: = coefficient of frictio
45、n,f = friction force, grams force,L = length of friction lever arm, cm, andP = test load, kg.NOTE 3Current test machines are supplied with a friction lever armhaving a length of 7.62 cm (3 in.), and friction force is displayed in unitsof grams force. Therefore, for these instruments, = 0.0170 f/P ca
46、n beused.or 5 0.00227 fL/P (2)where: = coefficient of friction,f = friction force, N,L = length of friction lever arm, cm, andP = test load, kg.NOTE 4For test instruments with a lever arm of 7.62 cm (3 in.) andfriction force displayed in Newtons, = 1.73 f/P.NOTE 5Friction force is read directly from
47、 the test machine and is theforce measured at a distance equal to the length of the friction lever armfrom center of rotation. Test machines may have friction force displayedas grams force or Newtons. Users should consult their operating manualsfor their equipment to verify the calculation equation.
48、12. Report12.1 Report the following information:12.1.1 Average wear-in scar, mm,12.1.2 Coefficient of friction for each increment of 10 kgf,12.1.3 Incipient seizure load, kilogram force, and12.1.4 Final average wear scar, mm.13. Precision and Bias13.1 PrecisionThe precision of this test method as de
49、ter-mined by the statistical examination of interlaboratory testresults is as follows:713.1.1 RepeatabilityThe difference between successiveresults obtained by the same operator with the same apparatusunder constant operating conditions on identical test materialwould, in the long run, in the normal and correct operation ofthe test method exceed the following values only in one case intwenty.Repeatability 5 0.20 3 x (3)where:x = average of successive results.13.1.2 ReproducibilityThe difference bet
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