What does a cathodic disbondment test primarily assess?

A cathodic disbondment test is designed to evaluate how well a coating adheres to a substrate in the presence of an electrochemical environment, specifically under conditions that simulate cathodic protection. This test measures the tendency of a coating to detach or disbond from the surface of the substrate when exposed to cathodic polarization, which can occur in corrosion protection systems.

The test aims to determine the degree and extent of disbonding that may happen due to factors like electrolyte penetration or the inherent properties of the coating material itself. Therefore, the correct answer reflects the primary focus of the test, which is assessing how much the coating may loosen or separate from the surface it is intended to protect. Understanding this aspect is critical for ensuring that coatings provide long-lasting protection against corrosion, as any disbondment could expose the substrate to corrosive agents and lead to premature failure of the protective system.