Daimler-Benz Adhesion Test

A method of checking the adhesion of PVD coatings that relies on observation of a Rockwell C indent. The stresses around the rim of a normal Rockwell C indent can cause microcracking and delamination of the coating. Because these stresses are greatest at the rim of the crater and then taper off radially outward, the size of the affected area gives an indication of the adhesion of the coating. A set of 6 standard drawings is used to classify the indent as a measurement value. Unfortunately, this test is not a pure adhesion test. It is affected by substrate material and hardness, the size of the indent, and coating stresses, thickness, and material.