Activation volume and the role of solute atoms in Al-Mg-Si alloy processed by equal channel angular extrusion

Grain refinement to the sub-micron scale was found enhance both strength and plasticity. In this size range, micro-mechanisms of deformation are not yet sufficiently specified. present work, strain rate sensitivity investigated in an Al-Mg-Si alloy processed by equal-channel angular extrusion. The microstructure controlled conventional transmission electron microscopy orientation imaging-ASTAR. as-quenched state, produces grains below 100 nm size. activation volume V reduced 70b3. Based on published theoretical models, we have shown that such alloy, pure grain boundary sliding cannot be revealed low-stress due intervention solute atoms. Beyond, stress-dependence consists with inverse Cottrell-Stokes behavior. This trend confirmed TEM which dislocation activity emission. Ageing at 150 °C increases contribution GBS whereas residual continues leveled.