Adhesion measurement procedures for kinetic and thermal spray coatings using a stud-pull tester

摘要

This paper reports on the use of an epoxy-coated stud-pull device to perform adhesion measurements on kinetic and thermal spray coatings for metal/metal and metal/ceramic systems.Four different methods were used for testing.The first method used the stud-pull device without a retaining cylinder pushing against the coating.The second method used a retaining cylinder.In the third method the coating was machined by electric discharge machining (EDM) to form a disc-like structure with a diameter identical to that of the epoxy-coated stud.The fourth method replaced the EDM machining by controlled rotary-disc cutting using SiC slurry to machine a disc-like structure in the coating.The first two methods gave a relatively consistent measurement of adhesion,provided the coating thickness is less than 2.5% of the stud diameter.For thicker coatings,both the third and fourth methods are recommended.