ABSTRACT
The scratch test has been used for some time to provide a measure of coat ing/substrate adhesion [1-6]. In the most commonly applied version of the test a diamond stylus is drawn across the coated surface under an increasing load until some well-defined failure occurs at a load which is often termed the critical load, Lc. Many types of failures are observed which include coating detachment, through-thickness cracking and plastic deformation or cracking in the coating or substrate [7-10]. In fact several different failure modes often occur at the same time and this can make results of the test difficult to interpret.
