Abstract
In-situ observations of crack propagation in sulfur-doped polycrystalline nickel were carried out using the specimens whose grain boundary microstructure was predetermined by SEM/EBSD analyses, in order to reveal the effect of grain boundary microstructure on the crack propagation process in segregation-induced brittle polycrystalline materials. The cracks predominantly propagated along high-energy random boundaries, and their propagation was inhibited by the distribution of low-energy coincidence site lattice (CSL) boundaries. Moreover, branching of cracks occurred when the crack propagation was inhibited by the distribution of CSL boundaries. It was suggested that the crack propagation was inhibited when the random boundary network was divided by the distribution of high fraction of CSL boundaries.
