1、Designation: F1044 05 (Reapproved 2011)1Standard Test Method forShear Testing of Calcium Phosphate Coatings and MetallicCoatings1This standard is issued under the fixed designation F1044; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revis
2、ion, 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.1NOTEUnits information was editorially corrected in January 2012.1. Scope1.1 This test method covers shear testin
3、g of continuouscalcium phosphate coatings and metallic coatings adhering todense metal substrates at ambient temperatures. It assesses thedegree of adhesion of coatings to substrates, or the internalcohesion of a coating in shear, parallel to the surface plane.1.2 The values stated in either SI unit
4、s or inch-pound unitsare to be regarded separately as standard. The values stated ineach system may not be exact equivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in non-conformancewith the standard.1.3 This standard may invo
5、lve hazardous materials, opera-tions, and equipment. This standard does not purport toaddress all of the safety concerns, if any, associated with itsuse. It is the responsibility of the user of this standard toestablish appropriate safety and health practices and deter-mine the applicability of regu
6、latory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E4 Practices for Force Verification of Testing MachinesE6 Terminology Relating to Methods of Mechanical TestingE8/E8M Test Methods for Tension Testing of MetallicMaterials3. Terminology3.1 DefinitionsTerminology E6 shall be c
7、onsidered asapplying to the terms used in this test method.4. Summary of Test Method4.1 Shear Method for Calcium Phosphate or Metallic Coat-ings:4.1.1 This test method consists of subjecting a specimenassembly composed of one coated and one uncoated compo-nent to a shear load. The components to be t
8、ested may bebonded together directly by thermomechanical means (forexample, sintering or diffusion bonding) or may be bondedtogether by use of a polymeric adhesive. The adhesive may bein film form or bulk form, but it must have a minimum bulkshear strength of 34.5 MPa 5000 psi or as great as themini
9、mum required adhesion or cohesion strength of the coat-ing, whichever is greater.4.1.2 The shear load must be applied parallel to the plane ofthe coating utilizing a tensile machine, which is capable ofdetermining the maximum strength of the coating or coatingattachment to the substrate interface.4.
10、2 Shear Method for Metallic Coatings OnlyThe lapshear method consists of subjecting a porous coated area tosingle shear loading, generally utilizing suitable polymericadhesive or bone cement adhesive and test jig in a tensionmachine, and determining the maximum shear stress requiredto obtain separat
11、ion (that is, the shear strength of the coating/substrate bond or shear strength of the coating).5. Significance and Use5.1 The shear test method is recommended for shear testingof calcium phosphate and metallic/substrate combinations andcan provide information on the adhesive or cohesive strengthof
12、 coatings under a uniaxial shear stress.5.2 The test method may be useful for comparative evalu-ation of adhesive or cohesive strengths of a variety of types ofcoatings. Information developed using this test method may beuseful for certain quality control and design purposes.5.3 The test method shou
13、ld not be considered to provide anintrinsic values for utilization directly in making calculationssuch as determining the ability of a coating to withstandspecified environmental stresses.1This test method is under the jurisdiction of ASTM Committee F04 on Medicaland Surgical Materials and Devices a
14、nd is the direct responsibility of SubcommitteeF04.15 on Material Test Methods.Current edition approved Oct. 1, 2011. Published January 2012. Originallyapproved in 1999. Last previous edition approved in 2005 as F1044 05. DOI:10.1520/F1044-05R11E01.2For referenced ASTM standards, visit the ASTM webs
15、ite, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United Stat
16、es.5.4 Processing variables, such as substrate preparation priorto coating, surface texture, coating technique variables orpost-coating heat treatment, or heat may introduce a significanteffect on the results of the shear test. The specimen beingevaluated must be representative of the actual end-use
17、 coating.6. Apparatus6.1 Testing MachinesMachines used for testing shallconform to the requirements of Practices E4. The loads used indetermining shear strength and yield strength shall be withinthe loading range of the testing machine as defined in PracticesE4. See also Test Methods E8/E8M.6.2 Grip
18、ping Devices:6.2.1 GeneralVarious types of grips may be used totransmit the load applied to the specimens by the testingmachine. To ensure axial shear stress, it is important that thespecimen axis coincide with the centerline of the heads of thetesting machine and that the coating test plane be para
19、llel to theaxial load. Any departure from this requirement (that is, anyeccentric loading) will introduce bending stresses that are notincluded in the usual stress calculation (force/cross-sectionalarea).6.2.2 Aligned Interface Method for Calcium Phosphate orMetallic Coatings:6.2.2.1 A drawing of a
20、typical gripping device for the testassembly is shown in Fig. 1.6.2.2.2 A drawing of the adapter to mate the shear fixture tothe tensile machine is shown in Fig. 2.6.2.2.3 A schematic of the test assembly is shown in Fig. 3.6.2.3 Lap Shear Method for Metallic Coatings Only:6.2.3.1 Lap Shear Testing
21、Bonding FixtureA bondingfixture of the type shown in Fig. 4 or equivalent shall bedesigned and machined with sufficient precision to minimizemovement of the specimen during curing of the adhesive.Some coatings, such as porous fiber metal coatings, may bebonded by sintering without the use of this fi
22、xture.6.2.3.2 Lap Shear Test Loading GripsA loading jig of thetype shown in Fig. 5 or equivalent shall be used. It shall bemade of hardened steel having a hardness of not less thanRockwell C60. To minimize the possible effect of distortion ofthe device under load, fitted and machined steel bolts may
23、 beused to hold the components together. The interfaces betweenthe tongue and clevises shall be smooth.7. Adhesive Bonding Materials7.1 Adhesive Bonding AgentA polymeric adhesive bond-ing agent in film form, or filled viscous adhesive cement, whenused, shall be identified and shall meet the followin
24、g require-ments:7.1.1 The bonding agent shall be capable of bonding thecoating on the test specimen components with an adhesiveshear strength that is at least 34.5 MPa 5000 psi or as great asthe minimum required adhesion or cohesion strength of thecoating, whichever is greater.7.1.2 In instances whe
25、re porosity extends to the coating/substrate interface, the bonding agent shall be sufficientlyviscous and application to the coating sufficiently careful toFIG. 1 Gripping Device for Shear TestingFIG. 2 Adapter to Mate the Gripping Device to the TensileMachineF1044 05 (2011)12assure that it will no
26、t penetrate through the coating to thesubstrate. The FM 1000 Adhesive Film3with a thickness of0.25 mm 0.01 in. has proven satisfactory for this test.7.1.3 If a material other than FM 1000 is used, or thecondition of the FM 1000 is unknown, it must be tested toestablish its equivalence to fresh FM 10
27、00. Testing should beperformed without the presence of the calcium phosphatecoating to establish the performance of the adhesive.8. Test Specimen8.1 General:8.1.1 In order to ensure precision and accuracy in testresults, it is important that care be exercised in the preparationof specimens, both in
28、machining and in the case of multi-partspecimens, in the assembly. Specimen components must beproperly aligned in order that generated stresses be purelyaxial, that is, parallel to the coated surface.8.1.2 Aligned Interface Method SpecimenThis shear testspecimen is illustrated in Fig. 6. A complete,
29、 assembled testassembly consists of two solid pieces; one with a coatedsurface and the other with an uncoated surface. The uncoatedsurface may be roughened to aid in the bonding of theadhesive.8.1.2.1 The cross-sectional area of the substrate upon whichthe coating is applied shall be nominal 2.84 cm
30、20.44 in.2.When specimens of another cross-sectional area are used, the3The sole source of supply of the apparatus known to the committee at this timeis Cytec Engineered Materials, Inc., 1300 Revolution St., Havre de Grace, MD21078. If you are aware of alternative suppliers, please provide this info
31、rmation toASTM International Headquarters. Your comments will receive careful consider-ation at a meeting of the responsible technical committee,1which you may attend.FIG. 3 Drawing of the Recommended Shear Test SpecimenAssemblyFIG. 4 Lap Shear Bonding FixtureFIG. 5 Lap Shear Loading GripsF1044 05 (
32、2011)13data must be demonstrated to be equivalent to 2.84 cm2standard cross-sectional area and the specimen size should bereported.8.1.3 Lap Shear SpecimenLap shear specimens shallconsist of substrate plates of the type shown in Fig. 7 orequivalent. The dimensions of test specimens differing fromFig
33、. 7 shall be included in the report.8.1.3.1 Test Specimen PositioningThe specimen shall bepositioned in the loading grips so as to cause the load axis tobe coincident with the plane of the adhesive. This may beaccomplished by suitably shimming the specimen within thegrips.8.2 Specimen Coating Prepar
34、ation:8.2.1 Coatings may be applied by any one of a number oftechniques. All test specimens for coating characterizationshall be prepared from indicative coating lots, using productionfeedstock lots and be coated on the same equipment used foractual implants. The coating should consist of a layer wh
35、ich ismechanically or chemically attached and covers the surface.8.2.2 All thermal treatments normally performed on thedevices should be performed on the test specimens.8.2.3 If employed, passivation and sterilization techniquesshould be consistent with those used for actual devices.8.2.3.1 If the p
36、assivation and sterilization processes can beshown not to influence the shear strength, these steps may beeliminated.8.2.4 InspectionBefore testing, visual inspections shouldbe performed on 100 % of the test specimens. Lack of coatingin highly stressed regions, as well as nonuniform coatingappearanc
37、e, shall be cause for specimen rejection.8.2.4.1 Coating Thickness MeasurementThe dimensionsof the coating planar surface shall be measured to the nearest0.80 mm 132 in. For lap shear specimens, the thicknessshould be measured at the center and all four corners of thecoated area to 0.03 mm 0.001 in.
38、 Coating thickness may notvary by more than 615 % of the thickness at the center.9. Procedure9.1 Prepare a minimum of five test specimens and apply thecoating of interest to the face of each in the same manner as foractual production devices.9.2 FM1000 Glue CuringThe test results achieved aregreatly
39、 dependent upon the adhesive used and the way in whichit is cured. One suggested adhesive commonly used withcalcium phosphate coatings is FM 1000 having a thickness of0.25 mm 0.01 in. This material has successfully been curedusing the following cycle:9.2.1 Align the adhesive with the surface of the
40、coating,taking precautions to align the adhesive in the center of thecoating.9.2.2 Apply a constant force using a calibrated high tem-perature spring, resulting in a stress of 0.138 MPa 20 psibetween the coating and the opposing device that will test thecoating.9.2.2.1 Maintain alignment of the coat
41、ing and the matchingcounterface during the curing of the adhesive.9.2.3 Place the assembly in an oven and heat at 176C350F for 2 to 3 h.9.2.3.1 The exact amount of time necessary to cure theadhesive will need to be determined by each user, as oventemperature may vary with load size and oven type. It
42、 issuggested that initially the curing cycle be optimized withoutthe coating present.9.2.4 Remove the cured assembly from the oven and allowit to cool to room temperature.9.2.5 Remove all excess glue which has protruded from thecoated surface without compromising the integrity of thesample.9.3 3M Sc
43、otch - Weld 2214 - NMF Structural AdhesiveGluing Procedure:9.3.1 Ensure that surface to be bonded is clean, degreased,and free of any loose particles and beads.9.3.2 Apply a thin layer of the adhesive evenly to the coatedsurface of the test coupons. A spatula or tongue depressor maybe used as an app
44、lication device.9.3.3 Squeeze excess adhesive out of the assembly usinghand pressure while coated faces of the test coupons are buttedtogether.FIG. 6 Aligned Interface SpecimenFIG. 7 Lap Shear Specimen (Metal Coatings Only)F1044 05 (2011)149.3.4 Place the specimen thus prepared in the fixture showni
45、n Fig. 5. During curing, ensure that the fixture maintains amild pressure at the joint, and force bonding faces to remainparallel and maintain the axial alignment.9.4 Direct Thermomechanical FabricationMetallic coat-ing specimens may be tested in either the aligned interface orsingle lap configurati
46、on. For sintered or diffusion bondedcoating systems, the test specimen configurations indicated inFigs. 4-7 may be constructed in a single process with thecoating application without the use of adhesive. The details ofthe specimen fabrication process will necessarily be unique toeach coating system.
47、 Perform appropriate inspections to ensurethat the microstructure and morphology of the coating in thetest specimen configuration are representative of finish produc-tion parts (see 8.2).9.5 Aligned Interface Test:9.5.1 Place the specimen assembly in the grips so that thelong axis of the specimen is
48、 perpendicular to the direction ofapplied shear load through the centerline of the grip assembly.9.5.2 Apply a shear load to each test specimen at a constantrate of cross-head speed of 0.25 cm/min 0.1 in./min. Continuethe test until complete separation of the components has beenachieved. Record the
49、maximum load applied.9.6 Lap Shear Test:9.6.1 Following curing, place the specimen in the testassembly shown in Fig. 6.9.6.2 Load the specimens at a constant rate of cross-headspeed of 0.25 cm/min 0.1 in./min. Continue the test untilcomplete separation of the components has been achieved.Record the maximum load applied.9.7 Discard specimens for which the adhesive has pen-etrated to the substrate and do not include the results in theanalysis and report.10. Stress Calculation10.1 Calculate the substrate area upon which the coating i
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