Intrinsic size effects in plasticity by dislocation glide

Size effects were seldom considered in plastic analysis until 15 years ago. However, many current technical applications of great and increasing importance — microelectronics, micro/nano-fabrication technologies, etc. — involve now plasticity confined to material distances well below 10−4 m. Knowledge of the plastic properties for pieces under such size is thus required for design. The interest on the scale influence on plastic problems is currently booming because several size effects in plasticity are known to exist in such small-scale range. aper is centred in highlighting a very fundamental size effect on the flow stress and in the work hardening rate of crystalline materials. It is an intrinsic size effect in the sense that it does not require the development of mesoscopic plastic gradients in the material. The proposed size effect is qualitatively and quantitatively explained by the bias of an analogy of dislocation glide with other physical phenomena describable by the invasion percolation model, like the 2-D fluid invasion of a porous medium.