Standard Test Method for Stereological Evaluation of Porous Coatings on Medical Implants Using Digital Images

Importancia y uso:

5.1 All these test methods are recommended for elementary quantification of the morphological properties of porous coatings.

5.2 These test methods may be useful for comparative evaluations of different porous coatings or different lots of the same porous coating.

5.3 All the methods should be performed on the same set of images of fields.

5.4 Statistical estimates of the distributions of the mean coating thickness and the volume percent void can be made. No estimate can be made of the distribution of intercept lengths in any individual field because the intercept length of a field is a single value. It would be possible to make an estimate of the distribution from the single values from many different fields of the same coating system.

5.5 If the image resolution is sufficient, then increasing the size of the fields, increasing the number of fields, or decreasing the grid spacing will increase the accuracy of the measurements obtained.

5.6 This method may be suitable for ceramic coatings if an accurate coating cross section can be produced. Producing an accurate ceramic coating cross section may require techniques other than standard metallographic techniques.

5.7 For coatings created for roughness having a mean thickness less than 300 µm and a standard deviation to the mean thickness of greater than 15 %, the use of this standard to determine the volume percent void or mean void intercept length may have some limitations, which should be identified accordingly. (For example, if mean thickness is 250 µm and standard deviation is 100 µm, then the ratio of standard deviation to mean thickness is ~40 %, which is greater than the 15 % limit.)

Subcomité:

F04.15

Referida por:

F1609-23, F2603-06R20, F2529-13R21, F3018-25, F3268-18A, F0561-19

Volúmen:

13.01

Palabras clave:

additive manufacturing; coating gradients; metallography; porosity; porous coatings; stereology; thickness;