| Abstract Scope |
Shear deformations by dislocation, twinning, and structural transformation in crystalline solids and shear-banding in metallic glasses share a key feature: autocatalysis driven by long-range elastic interactions, leading to strain avalanche and stress-plateaus in stress-strain curves. To achieve desired stress-strain behavior, alloys must be microstructurally engineered to suppress autocatalysis effectively. In this presentation, we demonstrate new alloy design strategies motivated by experiment and guided by mechanism-based modeling and simulation. In particular, we show the effectiveness of compositional and structural modulations (CSM) at nanoscales in suppressing autocatalysis and tailoring stress-strain behaviors during superelastic and plastic deformations by structural transformation, deformation twinning, and dislocations. Three examples will be discussed: CSM in regulating structural transformations in shape memory alloys and high entropy alloys, CSM in controlling twinning during creep deformation in Ni-base superalloys, and CSM in managing precipitation, martensitic transformation, and dislocation activities in Ti-alloys. |