Cyclic Softening by High Density Electric Current Pulses during Low Cycle Fatigueof Alpha-Ti

摘要

Strain-controlled, low cycle fatigue of metals generally consists of two separatestages. In the early stage, the material undergoes cyclic softening or hardening. At the end of the preliminary stage, the cycling turns to a steady state. In recent years, it has been found that electric current pulses affect material behavior, such as low cycle fatigue life of steel (1), the electroplastic response of various metals (2), recrystallization of cold worked alpha-Ti (3) and the microstructural modification at atomic, or even nuclear, level in amorphous alloys (4). In this paper, we shall show the effect of high current density, multiple d.c. pulses on strain-controlled, low cycle fatigue of alpha-Ti during the softening stage before the steady stage is reached. A significant effect was observed in that a secondary hardening peak was eliminated by the current pulses.