Fracture behavior and strain evolution of laminated composites

Laminated composites consisting of alternating layers of TiBw/Ti and Ti(Al) were prepared, and exhibited a superior elongation to fracture that is nearly 20 times higher than that of bulk TiBw/Ti composites. Coupling two- and three-dimensional fracture characterizations of TiBw/Ti-Ti(Al) laminated composites show distinct fracture characteristics including crack distribution, formation of tunnel cracks, and suppression of crack propagation. These experimentally observed fracture characteristics are intimately correlated with in situ monitored strain evolution process, by which we observed that strain localization is effectively suppressed by laminated structure, thus lowering the stress intensity near the crack tip as well as the driving force for crack propagation. As a consequence, laminated composites are not so sensitive to the early cracking, and exhibit a good strength-ductility combination.