ASTM F1147 – Standard Test Method for Tension Testing of Calcium Phosphate and Metallic Coatings
This test method covers tension testing of calcium phosphate and metallic porous coatings adhering to dense metal substrates at ambient temperatures. It assesses the degree of adhesion of coatings to substrates, or the internal cohesion of a coating in tension normal to the surface plane. The tensile test method consists of subjecting a specimen assembly composed of one coated and one uncoated component to a tensile load. In the case of the calcium phosphate coatings, the components to be tested must be bonded together by use of a polymeric adhesive. In the case of the metallic coatings, the components may either be bonded with the adhesive, or sintered together. The adhesive may be infilm form or bulk form, but it must have a minimum bulk tensile strength of 34.5 MPa (5000 psi) or as great as the minimum required adhesion or cohesion strength of the coating, whichever is greater.
The tensile test method is recommended for tension testing of calcium phosphate/substrate or porous metal coating/substrate combinations and can provide information on the adhesive or cohesive strength of coatings under (uniaxial) tensile stress. The test method may be useful for comparative evaluation of adhesive or cohesive strengths of a variety of types of coatings. Coatings may be applied using a variety of methods, including but not limited to plasma-spraying and sintering. Information developed using this test method may be useful for certain quality control and design purposes. The test should not be considered to provide an intrinsic value for utilization directly in making calculations such as determining the ability of a coating to withstand specified environmental stresses.
Example of test results are shown below.