The energy stored in fatigued metals

Abstract

Preliminary results are presented of determinations of stored energy and hardness for two series of specimens of O. F. H. C. copper fatigued at stresses which gave rise to failure at 2.8 x 10 4 cycles in one case and 10 6 cycles in the other. X-ray back-reflexion patterns are also presented. For the specimens fatigued at the high stress the stored energy is released by a combination of recovery and recrystallization, but for the specimens fatigued at the low stress only recovery has been observed. More energy is stored in the specimens fatigued at the higher stress. Some observations on work-softening during fatigue and of the energy stored in fatigued nickel are also reported.