1、Designation: F1160 14Standard Test Method forShear and Bending Fatigue Testing of Calcium Phosphateand Metallic Medical and Composite Calcium Phosphate/Metallic Coatings1This standard is issued under the fixed designation F1160; the number immediately following the designation indicates the year ofo
2、riginal adoption 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 the procedure for determiningthe she
3、ar and bending fatigue performance of calcium phos-phate coatings and of porous and nonporous metallic coatingsand for determining the bending fatigue performance ofmetallic coatings over sprayed with calcium phosphate. Thistest method has been established based on plasma-sprayedtitanium and plasma-
4、sprayed hydroxylapatite coatings. Theefficacy of this test method for other coatings has not beenestablished. In the shear fatigue mode, this test methodevaluates the adhesive and cohesive properties of the coatingon a metallic substrate. In the bending fatigue mode, this testmethod evaluates both t
5、he adhesion of the coating as well asthe effects that the coating may have on the substrate material.These methods are limited to testing in air at ambient tempera-ture. These test methods are not intended for application infatigue tests of components or devices; however, the testmethod which most c
6、losely replicates the actual loadingconfiguration is preferred.1.2 The values stated in either SI units 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. Combinin
7、gvalues from the two systems may result in non-conformancewith the standard.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 establish appro-priate safety and health practices and determi
8、ne the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2E6 Terminology Relating to Methods of Mechanical TestingE466 Practice for Conducting Force Controlled ConstantAmplitude Axial Fatigue Tests of Metallic MaterialsE467 Practice for Verification of C
9、onstant Amplitude Dy-namic Forces in an Axial Fatigue Testing SystemE468 Practice for Presentation of Constant Amplitude Fa-tigue Test Results for Metallic MaterialsE1012 Practice for Verification of Testing Frame and Speci-men Alignment Under Tensile and Compressive AxialForce ApplicationE1832 Prac
10、tice for Describing and Specifying a DirectCurrent Plasma Atomic Emission Spectrometer3. Terminology3.1 The definitions of terms relating to shear and fatiguetesting appearing in Terminology E6 shall be considered asapplying to the terms used in this test method.3.2 loading points, nobjects in conta
11、ct with the test beamor bar used to apply force to the beam or bar, usually radiusedto con concentrate the force to a point or a line.4. Summary of Test Method4.1 Shear Fatigue Testing:4.1.1 The intent of the shear fatigue test is to determine theadhesive or cohesive strength, or both, of the coatin
12、g.4.1.2 This test method is designed to allow the coating tofail at either the coating/substrate interface, within the coating,or at the interface between the coating and the adhesivebonding agent used to transmit the force to the coating.4.2 Bending Fatigue Testing:1This test method is under the ju
13、risdiction 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, 2014. Published July 2014. Originally approvedin 1991. Last previous edition approved in 2011 as F1160 05 (20
14、11). DOI:10.1520/F1160-14.2For 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 Summary page onthe ASTM website.Copyright ASTM International, 100 B
15、arr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14.2.1 The primary intent of the bending fatigue test is toquantify the effect that the coating has on the substrate it isapplied to. Secondarily, it may be used to provide a subjectiveevaluation of coating adhesion, (that
16、 is, spalling resistance,cracking resistance, and so forth).4.2.2 This test method is designed to first provide a substratefatigue strength to serve as a baseline to assess the effects of thecoating on the resulting fatigue strength of the system.5. Significance and Use5.1 The shear and bending fati
17、gue tests are used to deter-mine the effect of variations in material, geometry, surfacecondition, stress, and so forth, on the fatigue resistance ofcoated metallic materials subjected to direct stress for up to 107cycles. These tests may be used as a relative guide to theselection of coated materia
18、ls for service under condition ofrepeated stress.5.2 In order that such basic fatigue data be comparable,reproducible, and can be correlated among laboratories, it isessential that uniform fatigue practices be established.5.3 The results of the fatigue test may be used for basicmaterial property des
19、ign. Actual components should not betested using these test methods.6. Equipment Characteristics6.1 Equipment characteristics shall be in accordance withPractice E466, Section 7. See also Practices E467 and E1012and Terminology E1832.6.2 Shear Fatigue Test Grips:6.2.1 GeneralVarious types of grips m
20、ay be used totransmit the load to the specimens by the testing machine. Toensure axial shear stress, it is important that the specimen axiscoincide with the centerline of the heads of the testing machineand that the coating test plane be parallel to the axial force.Anydeparture from this requirement
21、 (that is, any eccentric loading)will introduce bending stresses that are not included in theusual stress calculation (force/cross-sectional area).6.2.2 A drawing of a typical gripping device for the testassembly is shown in Fig. 1.6.2.3 Fig. 2 shows a drawing of the adaptor to mate theshear fixture
22、 to the tensile machine6.2.4 Figs. 3 and 4 show schematics of the test setup.6.3 Bending Fatigue Test GripsThere are a variety oftesting machines that may be employed for this test (that is,rotating beam fatigue machines and axial fatigue machines).The gripping method for each type of equipment shal
23、l bedetermined by either the manufacturer of that equipment or theuser.7. Adhesive Bonding Materials7.1 Adhesive Bonding AgentA polymeric adhesive bond-ing agent in film form, or viscous adhesive cement, shall beidentified and shall meet the following requirements.7.1.1 The bonding agent shall be ca
24、pable 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. The 34.5 MPa bonding strengthis the static strength of the adhesive. The
25、 fatigue strength of theadhesive is usually less than that value. In fatigue the coatingunder test is often stronger than the adhesive causing thefracture to occur at the adhesive interface. If it is desirable tocontinue a fatigue test after fracture through the adhesive, thetest sample may be rebon
26、ded and testing.7.1.2 In instances where coating porosity extends to thecoating/substrate interface, the bonding agent shall be suffi-ciently viscous and application to the coating sufficientlydetailed, to ensure that it will not penetrate through the coatingFIG. 1 Gripping Device for Shear TestingN
27、OTE 1(2 PL) indicates the top and bottom adapters are identical.FIG. 2 Adaptor to Mate the Gripping Device to the Tensile Ma-chineF1160 142to the substrate. The FM 1000 Adhesive Film3with a thicknessof 0.25 mm 0.01 in. has proven satisfactory for this testmethod.7.1.3 If a material other than FM 100
28、0 is used, or thecondition of the FM 1000 is unknown, it must be tested toestablish its equivalence to fresh FM 1000. Testing should beperformed without the presence of the coating to establish theperformance of the adhesive. Two alternative adhesives thathave been used successfully are HYSOL 9514 a
29、nd 3M 2214non-metallic filled. Validation data on Hysol 9514 from In-dolab GmbH is presented in Appendix X1. These adhesivesmay not be suitable for HA coatings because they couldpenetrate the HA.8. Test Specimen8.1 Shear Fatigue Specimen for Calcium Phosphate andMetallic Coatings Only:8.1.1 The reco
30、mmended shear test specimen and setup isillustrated in Figs. 3 and 4, respectively. A complete assembledtest assembly 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 adhesion of theadhesive bonding agen
31、t.8.1.2 The cross-sectional area of the substrate upon whichthe coating is applied shall be a nominal 2.85 cm20.44 in.2.When specimens of another cross-sectional area are used, thedata must be demonstrated to be equivalent to the resultsproduced using the 2.85-cm2standard cross-sectional area andthe
32、 specimen size should be reported.8.2 Bending Fatigue Specimen for Calcium Phosphate,Metallic, and Calcium Phosphate-Metallic Composite Coat-ings:8.2.1 The type of specimen used will depend upon theobjective of the test program, the type of equipment, theequipment capacity, and the form in which the
33、 material isavailable. The R ratio for bending fatigue tests shall be 0.1 orless excluding rotating beam samples. For rotating beamsamples the R ratio shall be -1.0. However, the design shallmeet certain general criteria as follows:8.2.1.1 The design of the specimen shall be such that ifspecimen fai
34、lure should occur, it should occur in the testsection (reduced area as shown in Figs. 5-8).8.2.1.2 Specimens using a flat tapered beam configurationshould be designed such that a tapered gauge section with aconstant surface stress exists when the specimen is constrainedat one end and force applied t
35、hrough loading points perpen-dicular to and centered on the beam axis at the other end (thatis, cantilever loading, usually a tapered cantilever beam asshown in Fig. 10).8.2.1.3 Four-point bend specimens consisting of straightbars of constant, usually rectangular, cross section loaded infour-point b
36、ending also produce a region of constant surfacestress in the center span between the two center loading points.The distance between the two external loading points shallalways be identical (see Fig. 9).8.2.1.4 Rotating beam specimens may have uniquedimensions, depending upon the type of machine use
37、d. Appro-priate manufacturersspecifications for these specimens shouldbe used.8.2.1.5 The tensile surface edges of the flat tapered cantile-ver beam specimen and the four point bend specimen may bebroken to a small non zero radius to avoid stress concentrationsat the edge.8.3 Specimen Coating Prepar
38、ation:8.3.1 Coatings may be applied by any one of a number oftechniques. All test specimens for coating characterization3The 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 o
39、f alternative suppliers, please provide this information toASTM International Headquarters. Your comments will receive careful consider-ation at a meeting of the responsible technical committee,1which you may attend.FIG. 3 Schematic of the Shear Test SetupFIG. 4 Drawing of the Recommended Shear Test
40、 Specimen As-semblyFIG. 5 Bending Fatigue Specimen With Tangentially BlendingFillets Between the Test Section and the Ends for Rotating Beamor Axial LoadingF1160 143shall be prepared from indicative coating lots, using productionfeedstock lots and be coated on the same equipment used foractual impla
41、nts. The coating should consist of a layer which ismechanically or chemically attached and covers the surface.8.3.2 Coatings should be applied as follows:8.3.2.1 For the shear fatigue specimens, the coating shouldbe applied to the 19.05-mm 0.75-in. diameter face only (seeFig. 3).8.3.2.2 For the rota
42、ting beam and axial fatigue test speci-mens the coating shall be applied all around and extend slightlybeyond the reduced sections (see Figs. 5-8). For the tension-tension bending fatigue specimens, the coating shall be appliedto the side that will be loaded in tension only. The coating shallextend
43、well beyond the tapered gauge area to keep stressconcentrations at the transition from coated surface to uncoatedsurface out of the high stress regions (Fig. 10) On thefour-point bend test sample the coating shall be extendedoutside of the inner loading points to keep a possible stressconcentration
44、at the transition from coated surface to uncoatedsurface outside the maximum stress center region.).8.3.3 All thermal treatments normally performed on thedevices should be performed on the test specimens.8.3.4 If used, passivation and sterilization techniques shouldbe consistent with those used for
45、actual devices.8.3.5 InspectionBefore testing, visual inspections shouldbe performed on 100 % of the test specimens. Non-uniformcoating density shall be cause for specimen rejection. For theshear fatigue specimen, lack of coating on the coated face shallbe cause for specimen rejection. For the bendi
46、ng fatiguespecimen, lack of coating in highly stressed regions shall because for specimen rejection.9. Procedure9.1 The number of specimens required for testing, as well asthe test methods in which the fatigue data may be interpreted,can vary. Several test methods are referenced in this testmethod.4
47、,5,69.2 The type of specimen used will depend upon theobjective of the test program, the type of equipment available,the equipment capacity, and the form in which the material isavailable. The specimen chosen should come as close tomatching the intended application as possible.9.3 The test frequency
48、 used shall not exceed 50 Hz forrotating beam tests and 30 Hz for bending fatigue tests. The testfrequencies should be carefully selected to avoid inertial effectsfrom the mass of the test fixtures.9.4 Shear Fatigue Specimens:9.4.1 Curing the AdhesiveThe test results achieved aregreatly dependent up
49、on the adhesive used and the way in whichit is cured. One suggested adhesive is FM 1000 having athickness of 0.25 mm 0.01 in. This material has successfullybeen cured using the following cycle:9.4.1.1 Align the adhesive with the surface of the coating,taking precautions to align the adhesive in the center of thecoating.9.4.1.2 Apply a constant force using a calibrated hightemperature spring, resulting in a stress of 0.138 to 0.295 MPa20 to 43 psi between the coating and the opposing device thatwill test the coating.4Collins, J.A., Failure of Materials in Mech
