Mechanisms of Fatigue Damage in Face Centred Cubic Metals

Abstract

THE work of Wood et al.^1,2 has shown that fatigue damage occurs by different mechanisms in different regions of the S/N curve, these being designated as the H mechanism at high stress levels where fatigue life increases slowly with decreasing stress amplitude, and the F mechanism at lower stress levels where fatigue life increases rapidly with decreasing stress. There is also a pseudo-safe or S region. A number of workers^3–6, however, have suggested that there is a less clear-cut distinction between the mechanisms occurring at the different stress levels than the results of Wood et al. indicate, and we discuss here the role of material properties such as texture and ductility on the operative mechanisms of fatigue damage.