Microcracks in fatigued FCC polycrystals by interaction between persistent slip bands and grain boundaries

Abstract Persistent slip bands (PSB) are zones of high plastic strain localization in fatigued fee metals. They cannot propagate across the grain boundaries of polycrystalline specimens. Consequently, a local stress field should exist near the end of the PSB, “inducing” new PSBs in the neighbouring grain or initiating cracks within the grain boundary. This interaction between PSBs and grain boundaries will be discussed in the present paper. The observed effects may be divided into few characteristic groups, the occurrence of which depends on the geometrical relations between PSB, grain boundary and specimen axis.