1. First developments

The first mention of scratch testing as a qualitative method of measuring coating adhesion dates back to the 1950s by Heavens who, applying a constant load to the surface of a coating via a penetrator, observed surface damage that caused delamination of the film. The applied loads that created this specific damage (cracking, delamination) are defined as "critical" loads. Subsequent work by Benjamin and Weaver in the 1960s led to a model...