Materials science perspective of metal fatigue resistance

Abstract

An interdisciplinary view of metal fatigue in polycrystalline metals is presented. Fatigue resistance is defined in terms of the difficulty of crack growth in one of two possible directions, the first being related to the texture of a material, and the second to the orientation of the applied loading system. The fatigue initiation phase is considered to be negligible for polycrystalline metals, and fatigue limits are equated to one of two threshold conditions, one quantified in terms of microstructural fracture mechanics, and the other determined by continuum mechanics. The importance of the intensity and distribution of microstructural barriers to fatigue crack growth is underlined, especially in relation to mechanical conditions such as stress–strain state and to material conditions such as grain size and the shape and orientation of inclusions and their size relative to microstructural barriers. © 1993 The Institute of Materials.