Use of the microindentation technique for determining interfacial fracture energy

The microindentation technique was used to determine the interfacial fracture energy of epoxy coatings on soda-lime glass substrates. An analytical model was developed for calculating fracture energy based on indenter load versus debond crack size measurements. Finite-element analysis was used to determine the relative amounts of opening and shear loadings at the debond crack tip. The calculated fracture energies are compared to values determined by the double-cantilever-beam technique and the four-point flexure-beam technique.