The progressive intensification and attenuation of yield point phenomenon in a new polycrystalline zirconium alloy: Anisotropic response of work hardening-softening transition

We report an interesting phenomenon in a new polycrystalline zirconium alloy that the yield drop behavior is progressively intensified and attenuated with the increase of strain. This yield discontinuity is ascribed to the recombination of climb-dissociated partials introduced by previous strain, and the work hardening or softening stage with respectively increasing or decreasing partial dislocations results in the progressively intensification or attenuation of yield drop, respectively. The maximum of yield drop value and increment-decrement transition strain of yield drop are relatively higher along rolling direction (∼5.5 MPa and ∼21%, respectively) than transverse direction (∼4.6 MPa and ∼10%, respectively), stemming from the anisotropic response of the strain hardening-softening transition.