1、Designation: F1978 12Standard Test Method forMeasuring Abrasion Resistance of Metallic Thermal SprayCoatings by Using the Taber Abraser1This standard is issued under the fixed designation F1978; the number immediately following the designation indicates the year oforiginal adoption or, in the case o
2、f 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. Scope*1.1 This test method quantifies the abrasion resistance ofmetallic coatings produced by thermal s
3、pray processes on flatmetallic surfaces. It is intended as a means of characterizingcoatings used on surgical implants.1.2 This test uses the Taber Abraser,2which generates acombination of rolling and rubbing to cause wear to the coatingsurface. Wear is quantified as cumulative mass loss.1.3 This te
4、st method is limited to flat, rigid specimens thatdo not react significantly with water and do not undergo aphase transformation or chemical reaction between roomtemperature and 100C in air.1.4 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in
5、 thisstandard.1.5 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 applicableregulatory limitations prior to use.2. Refere
6、nced Documents2.1 ASTM Standards:3E691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodG195 Guide for Conducting Wear Tests Using a RotaryPlatform, Double-Head Abraser3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 abraser, ninstrumen
7、t that is designed to determinethe resistance of surfaces to composite rolling and rubbingaction.3.1.2 particle shedding, nloss of surface particles andfragments from a coating.3.1.3 thermal spray coating, ncoating produced by spray-ing melted or softened powder or wire by means of combus-tible gase
8、s, plasma, or two-wire arc.3.1.4 weight loss, namount of mass removed by the testapparatus over the course of testing.4. Summary of Test Method4.1 This test method uses a Taber Abraser with H-22Calibrade (trademarked) wheels2and the 250-g mass of theabrading head without added weights. A specimen is
9、 abradedusing rotary rubbing action under controlled conditions ofpressure and abrasive action. The test specimen, mounted on aturntable platform, turns on a vertical axis against the slidingrotation of two abrading wheels. One abrading wheel rubs thespecimen outward toward the periphery and the oth
10、er inwardtoward the center. The resulting abrasion marks form a patternof crossed arcs over an area of approximately 30 cm2.Specimens are abraded repeatedly and cleaned ultrasonicallyfor a set number (2 to 100) of rotational cycles. The specimensare weighed after each cleaning, and the mass loss is
11、themeasure of abrasive wear to the specimen.5. Significance and Use5.1 This test method provides a means to evaluate theresistance to particle shedding of a thermal spray coating. Suchparticle shedding might occur during surgical insertion of animplant or as the result of micromotion of the implant
12、afterinsertion.5.2 This abrasion test method may be useful for qualitycontrol analysis of a coating, and it can be used to evaluate theeffects of processing variables, such as substrate preparationbefore coating, surface texture, coating technique variables, orpostcoating treatments, any of which ma
13、y influence the sus-ceptibility of the coating to particle shedding.1This test method is under the jurisdiction of ASTM Committee F04 on Medicaland Surgical Materials and Devices and is the direct responsibility of SubcommitteeF04.15 on Material Test Methods.Current edition approved June 1, 2012. Pu
14、blished June 2012. Originallyapproved in 1999. Last previous edition approved in 2007 as F1978 00 (2007)2.DOI: 10.1520/F1978-12.2Trademarked. The sole source of supply of the apparatus known to thecommittee at this time is Taber Industries, North Tonawanda, NY 14120 USA. Ifyou are aware of alternati
15、ve suppliers, please provide this information to ASTMHeadquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee,1which you may attend.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at servic
16、eastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, Unite
17、d States.5.3 This abrasion test method is for flat plate-shaped speci-mens of a size sufficient that the wheels of the abrader do notleave the surface of the specimen. It is not recommended,however, for devices with other shapes or sizes.6. Apparatus6.1 Taber Abraser Model 5150, or equivalent as des
18、cribedin Guide G195, with abrading head of 250-g mass and noadded weights.6.2 H-22 Taber Calibrade Wheels, or equivalent.6.3 Taber Vacuum Unit, made by Shop-Vac (trademarked),27.4 amps, or equivalent.6.4 Taber Wheel Refacer Model 250,2or equivalent.6.5 Ultrasonic Cleaning Unit, for cleaning specimen
19、s afterabrading.6.6 Drying Oven, capable of operation at 100 6 2C, fordrying specimens.6.7 Analytical Balance, capable of weighing specimens toan accuracy of 0.0001 g.7. Test Specimen7.1 Abrasion test specimens shall be approximately 10-cmsquares or 10-cm diameter circles of at least 0.16-cm but not
20、greater than 0.64-cm thickness, with a 0.64-cm diameter holethrough the center to allow the specimen to fit on the specimentable screw of the Taber Abraser. For substrates other thantitanium, consideration shall be given to the weight of the testspecimen relative to the capacity of the analytical ba
21、lance.NOTE 1For specimens thicker than 0.64-cm but less than 1.27-cm, anextension nut such as type S-212or equivalent may be used in place of theclamp nut. When using the S-21 extension nut, the clamp plate is not usedand the specimen center hole shall be 0.96-cm.7.2 The coating shall be applied in
22、a manner representativeof that used on the finished surgical implant.7.3 A minimum of six samples for each coating shall beprepared. At least one set shall contain seven samples.7.4 One specimen, randomly selected, from each group ofsix specimens shall be reserved to measure weight loss causedby ult
23、rasonic cleaning. This specimen shall be called the“blank” specimen and shall be weighed, cleaned, and re-weighed for an equal number of times to the cleaning andweighing of the abraded specimen.7.5 Of the seven sample set, one sample shall be selected todetermine the time required for ultrasonic cl
24、eaning.8. Procedure8.1 General Information:8.1.1 If there is more than one set of specimens to test, thespecimens shall be tested in a random sequence.8.1.2 A single complete specimen run shall consist of aseries of partial runs, commencing with an initial two-cyclepartial run and continuing until 1
25、00 cycles have been com-pleted. Once a specimen run is initiated, no other specimensshall be tested using the same wheel until the specimen run isfinished.8.1.3 At the start of each new complete specimen run, thedisplay indicating the number of cycles run shall be reset. TheTaber Abraser counts cumu
26、lative cycles (cycles completed)and so the number of cycles set for each partial run shall be thecumulative number of cycles (2, 5, 10, or 100) designated asthe end of that partial run.8.2 Ultrasonic CleaningBefore running the battery oftests, the time required for ultrasonic cleaning shall be deter
27、-mined.8.2.1 Using the analytical balance, weigh the seventhsample as described in 7.5 no fewer than three times and recordthe average weight of these measurements.8.2.2 Prepare the Taber Abraser following steps 8.4.2 to8.4.9.8.2.3 Set the Taber Abraser for ten cumulative cycles andstart the turntab
28、le.8.2.4 Clean the sample for ten minutes with a fresh salinesolution (see 8.4.1), with the ultrasonic cleaner to be used forthe coating analysis.8.2.5 Place the cleaned sample in a 100C oven and dry for10 min.8.2.6 Allow the sample to cool to room temperature beforeweighing.8.2.7 Using the analytic
29、al balance, weigh the sample nofewer than three times and record the average weight of thesemeasurements.8.2.8 Repeat 8.2.4 to 8.2.7 until the same mass (withinbalance error) is recorded for two consecutive cleanings.8.2.9 Record the total number of cleanings performed in8.2.4 to 8.2.8.8.2.10 Determ
30、ine the required cleaning time necessary toobtain a stable mass, as (10(n-1) min, where n is the totalnumber of cleanings determined in 8.2.9.NOTE 2Handle specimens by the edges to prevent unintentionalparticle shedding.8.3 Reference StandardsEach group of six specimensshall include one unabraded “b
31、lank” specimen, as specified in7.4. Once in every six tests, an unabraded specimen shall beused as a control to determine the weight loss caused by theultrasonic cleaning. This specimen shall be weighed, cleaned,and reweighed for as many times as would normally be done ifabrasion testing were being
32、performed. These values shall belogged as “blank” weight loss values.8.4 Operation:8.4.1 Prepare a fresh cleaning solution for the ultrasoniccleaner by adding 0.1 6 0.005 g of reagent grade NaCl to eachlitre of deionized water8.4.2 Resurface the abrading wheels using the Taber WheelRefacer Model 250
33、 for each new specimen. Check the radius ofthe wheel. It is essential that the radius of the abrading wheelsnot fall below the marked minimum level over the course of thetest. Should the wheel radius fall below the labeled mark, thetest run shall be discarded and a new specimen shall be run inits pl
34、ace.8.4.3 Mount the H-22 Calibrade wheels by placing thewheel marked “Left Wheel” on the left hand abrading head andthe wheel marked “Right Wheel” on the right hand abradinghead, with the labels facing toward each other.8.4.4 Abrasion shall be done with only the 250-g mass ofthe abrading head assemb
35、ly. No extra weights shall be added tothe abrading head.F1978 1228.4.5 Clean the specimen for the time determined in 8.2.10using an ultrasonic cleaner with saline solution. This solutionshall be changed to a fresh solution before the first cleaningdone that day.8.4.5.1 Place the cleaned specimen in
36、a 100C oven for 10min to dry.8.4.5.2 Allow the specimen to cool to room temperaturebefore weighing.8.4.5.3 Using the analytical balance, weigh the specimen nofewer than three times, and record the average of these weightmeasurements on a data sheet.8.4.6 Place the specimen on the Taber Abraser turnt
37、able,coating side up such that the screw projects through the hole inthe center of the specimen. Place the clamp plate over thespecimen, and secure the specimen and clamp plate to theturntable using the clamp nut.8.4.7 Lower the vacuum pick up nozzle. The gap betweenthe specimen and vacuum pick up n
38、ozzle should be adjusted to3 mm.8.4.8 Lower the abrading heads gently so that the abradingwheels rest on the surface of the specimen.8.4.9 Set the Taber Abraser to reach the appropriate numberof cumulative cycles (2, 5, 10, or 100). Set the vacuum suctionlevel by depressing the “vacuum suction level
39、” key andentering 100. Start the Taber vacuum prior to beginning the testby depressing the “vacuum only” key. Let the vacuum run forno less than5stoallow the vacuum to reach full power, thenstart the turntable rotation by pressing the “start” key. When theturntable rotation for the specific partial
40、run is completed, turnoff the abraser and vacuum by pressing the “stop” key.8.4.10 Clean, dry, cool, and weigh the specimen as before(see 8.4.5).8.4.11 Repeat 8.4.6 to 8.4.10 for 5, 10, and 100 cumulativecycles.8.4.12 Repeat the steps specified in 8.4.2 to 8.4.11 for allspecimens not reserved as bla
41、nks for the test.8.4.13 Run each blank through the steps specified in 8.4.5 to8.4.11 skipping the steps specified in 8.4.6 to 8.4.9.9. Calculation9.1 Calculate the cumulative mass loss for each specimenfor the number of revolutions used with the following equation:Dwn5,wo. ,wn. (1)where:n = number o
42、f cumulative cycles to which specimenhas been exposed (2, 5, 10, 100),Dwn= cumulative mass loss for n cycles,= average of three mass measurements at the start ofthe test, and= average of three mass measurements after n cumu-lative cycles.10. Report10.1 The report shall include the following informat
43、ion:10.1.1 Identification of the test coupon materials includingtraceability information, such as coating process lot and rawmaterial lot numbers.10.1.2 Dimensional data including coupon dimensions andcoating thickness dimensions.10.1.3 The number of specimens tested.10.1.4 Nominal laboratory temper
44、ature and humidity duringthe test.10.1.5 The number of minutes needed for ultrasonic clean-ing, as determined in 8.2.10.10.1.6 All cumulative mass losses following abrasionand/or ultrasonic cleaning associated with each specimen orblank.10.1.7 The mean cumulative mass loss and its standarddeviation
45、for 2, 5, 10, and 100 cycles.10.1.8 Observations made during the course of the study,including but not limited to, observation of wear tracks andwhen they occur, the appearance of discoloration of thespecimen, the removal of large sections of coating, andevidence of corrosion.11. Precision and Bias1
46、1.1 An interlaboratory study (ILS) was conducted to es-tablish the precision and bias of this test method. The numberof laboratories, materials, and determinations in this study meetthe minimum requirements for determining precision as pre-scribed in Practice E691 (see Table 1). These tests were don
47、efor 2, 5, 10, and 100 cycles for a total of 12 material and cyclecombinations.11.2 PrecisionPrecision, characterized by repeatability,Sr, and reproducibility, SR, have been determined for thematerials and cycle combinations provided in Table 2.12. Keywords12.1 abrasion; particle shedding; porous co
48、atings; TaberAbraser; thermal spray coatings; wearTABLE 1 ILS Study ParametersThis Study Practice E691 minLaboratories 6 6Materials 3 3Determinations 5 2F1978 123APPENDIX(Nonmandatory Information)X1. RATIONALEX1.1 Abrasion may occur in implantable devices withmetallic coatings produced by thermal sp
49、ray processes. Exces-sive weight loss, however, is undesirable, as it may lead to thirdbody wear of articulating surfaces.X1.2 Although the use of sprayed flat specimens and theTaber Abraser do not mimic the effect of bone and daily usage,this test method has been shown to be a reliable measure of theaverage wear/abrasion resistance of a thermal spray coating.X1.3 Measurements are taken at 2, 5, 10, and 100 cycles. Aminimum of two cycles was chosen to ensure that the turntableof the Taber Abraser makes at least one complete rotationbefore any abrasion weight loss
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