Electron microscope study of surface markins left by unsteady cleavage crack propagation in NaCl single crystals

Abstract

Surface markings left by an unsteadily propagating cleavage crack in NaCi single crystals have been studied by electron microscopy as a function of accelerations and decelerations of the crack. As a result, a comprehensive description of the sequence of markings present between two successive stopped crack fronts has been obtained. Models are proposed illustrating the manner in which the activation of the longitudinal and transverse slip systems and their interaction can account for the cleavage markings observed.