(03-20-2017, 02:54 PM)grepper Wrote: With a metal that can be work hardened, is it possible to have metal fatigue/failure without hardening happening? Is one always indicative of the other?
Is this a sensible question?
It is definitely a sensible question!
In my understanding the metal fatigue is conditioned by prior repeated plastic deformations of the material. If the plastic deformations were fast enough they caused that the metal was work hardened. If the plastic deformations were slow then the material was probably not hardened because the newly produced dislocations could have enough time to dissipate in the material.
The so called Deborah number tells us if the deformation is fast or slow for the material under consideration and given observation time.
Jan