ISO 19207:2016 specifies the classification method of adhesive strength for thermal spray coatings at room temperature by using Vickers hardness testing machine. It classifies the adhesive strength, called adhesion index, evaluated from the maximum indentation force without visible cracking, and it is applicable for relative dense metal coatings, ceramic coatings and cermet coatings. It can be used within comparison within each coating system.
The indentation method is not recommended for very thin and very porous coatings and also for the coating system with lower cohesion strength than adhesion strength. It is recommended that this test method can be applied for a coating of which porosity is less than approximately 15 %.