ASTM_F_1659_-_95.pdf

Designation:F 1659 95Standard Test Method forBending and Shear Fatigue Testing of Calcium PhosphateCoatings on Solid Metallic Substrates1This standard is issued under the fixed designation F 1659;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers the procedure for the perfor-mance of calcium phosphate ceramic coatings in shear andbending fatigue modes.In the shear fatigue mode this testmethod evaluates the adhesive and cohesive properties of thecoating on a metallic substrate.In the bending fatigue mode,this test method evaluates both the adhesion of the coating aswell as the effects that the coating may have on the substratematerial.These test methods are limited to testing in air atambient temperature.These test methods are not intended forapplication in fatigue tests of components or devices;however,the test method that most closely replicates the actual loadingconfiguration is preferred.1.2 The values stated in SI units are to be regarded as thestandard.The inch-pound units given in parentheses are forinformation only.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 determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:E 6 Terminology Relating to Methods of Mechanical Test-ing2E 206 Definitions of Terms Relating to Fatigue Testing andthe Statistical Analysis of Fatigue Data3E 466 Practice for Constant Amplitude Axial Fatigue Testsof Metallic Materials2E 467 Practice for Verification of Constant Amplitude Dy-namic Loads in an Axial Load Fatigue Testing Machine2E 468 Practice for Presentation of Constant Amplitude Fa-tigue Test Results for Metallic Materials23.Terminology3.1 Definitions:3.1.1 The definitions of terms relating to shear and fatiguetesting appearing in Terminology E 6 and Terminology E 206shall be considered as applying to the terms used in this testmethod.4.Summary of Test Methods4.1 Shear Fatigue Testing:4.1.1 The intent of the shear fatigue test is to determine theadhesive or cohesive strength of the coating,or both.4.1.2 This test is designed to allow the coating to fail ateither the coating/substrate interface,within the coating,or atthe glue/coating interface.4.2 Bending Fatigue Testing:4.2.1 The intent of the bending fatigue test is to quantify theeffect that the coating has on the substrate to which it isapplied.It may also be used to provide a subjective evaluationof coating adhesion(that is,spalling resistance,crackingresistance,etc.).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 fatigue tests are used to deter-mine the effect of variations in material,geometry,surfacecondition,stress,etc.,on the fatigue resistance of calciumphosphate coated metallic materials subjected to direct stressfor up to 107cycles.These tests may be used as a relative guideto the selection of calcium phosphate coated materials forservice under conditions of repeated 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 design.Actual components should not betested using these test methods.6.Equipment Characteristics6.1 Equipment characteristics shall be in accordance withSection 7 on Adhesive Bonding Materials of Practice E 466.6.2 Shear Fatigue Test Grips:6.2.1 GeneralVarious types of grips may 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 machine1This test method is under the jurisdiction of ASTM Committee F-4 on Medicaland Surgical Materials and Devices and is the direct responsibility of SubcommitteeF04.13 on Ceramic Materials.Current edition approved Nov.10,1995.Published May 1996.2Annual Book of ASTM Standards,Vol 03.01.3Discontinued;see 1987 Annual Book of ASTM Standards,Vol 03.01.1Copyright ASTM,100 Barr Harbor Drive,West Conshohocken,PA 19428-2959,United States.and that the coating test plane be parallel to the axial load.Anydeparture from this requirement(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