scope:

This Technical Report describes a method for characterizing the porosity of thermally sprayed coatings by metallographical examination.

This method is particularly applicable to oxide coatings, such as Al₂O₃, ZrO₂ and TiO₂, produced by plasma spray. It also considers the purposes to test the size, shape and density of pores for thermally sprayed coatings.

Purpose

The main purpose of porosity measurement is to determine the quality of a thermally sprayed coating and its freedom from porosity, particularly on those areas of the significant surface that demand a functional requirement.

This Technical Report provides a standard process that is suitable for determining the porosity of thermally sprayed coatings, as part of the total quality assurance programme.

This Technical Report is also intended to provide a standard way to present the porosity of thermally sprayed coatings.