Non-Destructive Measurement of Coating Adhesion

Good practical adhesion is essential to enable coatings to maintain their protective function in aggressive environments. Initial values are dictated by operational and formulation factors. However subsequently ‘adhesion' is not a fixed parameter but varies continually in response to the service conditions. Inadequate adhesion will manifest itself in different ways, which at the limits are catastrophic. Both coatings manufacturers and users could gain competitive advantage from improved methods to test and predict the adhesive performance of coatings in service. Tests currently used by the industry are often relatively crude, such as a simple tape and cross hatch test. The tests may distort the results and are destructive. Not only is this inconvenient but it raises questions of relevance if the destructive process is outside the normal operating parameters, or introduces testing artefacts such as an additional bonded surface.

Non-destructive testing (NDT) present a difficult challenge but has many practical attractions. In addition the nature of non-destructive testing requires a much deeper understanding of the causal factors and therefore aids the process of problem diagnosis.

This project will investigate a number of candidate non-destructive methods for assessing coating adhesion and relate them to the different modes of failure encountered in aggressive environments, or at high stress levels. Emphasis will be placed on methods which could be employed for field inspection, quality control purposes, service life prediction and product development.

Further Information

If you are interested in this, or any other project, please contact Richard Holman.