Crystalline Deformation in the Small Scale

Abstract

In the last two decades, experimental observations demonstrated-and numerical simulations confirmed-that plastic deformation in the small scale, i.e. at the micron or sub-micron scales, is different from that at the macro-scale; this phenomenon is known as size effect. It was observed mostly in indentation, torsion and bending experiments, being ascribed to strong gradients of strain in such deformation processes. The size effect was also reported in uniaxial micro-and nano-pillar compression experiments in spite of their inherent lack of (or limited) macroscopic strain gradients. In the present study, we first review some critical and essential experimental studies that were conducted over the years to analyse various mechanisms that govern deformation in the small scale. In the second part, different modelling approaches describing this phenomenon are briefly reviewed.