Fatigue behavior of refined copper without and with severe deformation using Constant Angular Channel Pressure

Abstract

An investigation has been carried out in order to study the effect of severe plastic deformation by Equal Channel Angular Pressing (ECAP) in a refined copper on fatigue behavior. Specimens were annealed and half of them were deformed through 8 ECAP passes following the route Bc, obtaining an ultrafine grain size. The severely deformed Cu showed an increase in the yield stress and tensile strength. The fatigue tests were performed on an axial load machine applying  fluctuating stress cycles at 150 Hz frequency. An increase in fatigue life was obtained. By fractographic study it was found that fatigue cracks have their  beginnings in the free surface of the specimens, thus it can be concluded that the increase in the fatigue behavior is due to the severe plastic deformation.