1997 Volume 37 Issue 12 Pages 1224-1229
Low-cycle fatigue behavior of Cu-1.53mass%Fe alloy single crystals with and without precipitated γ-Fe particles was examined. Although the γ-Fe particles are coherent and shearable, no cyclic softening was observed. Dislocation structures in solution-treated specimens were similar to those of fatigued pure Cu single crystals. However, in aged specimens, the precipitated γ-Fe particles retard the development of a dislocation structure. As a result, more uniform dislocation distribution compared with that in solution-treated specimens was observed, at least in the initial stages of cyclic deformation. Magnetic measurements revealed that the majority of the γ-Fe particles had transformed martensitically into α-Fe during the fatigue tests. The transformation changes the particle character from "shearable" to "nonshearable". This change enhances the uniform deformation and the homogeneous dislocation distribution and leads to the absence of cyclic softening.
