Abstract
We report on the novel application of nanoscratch characterization to provide insight into the plasticity mechanisms responsible for the behaviour of composites. Accordingly, we conduct deformation characterization with nanoscratch testing (DCNT) to study the deformation behaviour of two B sub(4)C reinforced ultrafine grained Al alloy tri-modal composites with average B sub(4)C particle sizes of ~1-6 mu m and ~500 nm, respectively. To highlight the type of mechanistic information revealed in a DCNT study of composites, we concentrate on the influence of B sub(4)C particle size on deformation mechanisms.