| Abstract Scope |
In contrast to conventional polycrystalline alloys, metallic glasses (MGs) are generally expected to soften under plastic deformation, impeding their wider application. While there have been many hints that MGs might show strain-hardening in particular circumstances, it is only recently [1] that the expected correlation of strain-hardening and suppression of shear-banding has been confirmed for unconstrained deformation. The gradient of the plot of flow stress as a function of strain, normalized by the initial yield stress, characterizes the efficiency of strain-hardening of a material. For a conventional stainless steel and for many polycrystalline alloys, this efficiency is approximately 7. In highly rejuvenated MGs [1], this is approximately 45. Very recent measurements, on MGs that show deformation-induced crystallization, reveal hardening efficiencies as high as 300. We explore the origins and applicability of such rapid strain-hardening.
[1] J. Pan, Yu.P. Ivanov, W.H. Zhou, Y. Li, A.L. Greer, Nature 578 (2020) 559‒562. |