Stress dependence of mobile dislocation density and dislocation velocity from Lüders band front propagation velocity

Direct measurements (1) of the displacement of dislocations due to pulse loading of iron - 3.25 per cent silicon alloy have shown that the stress dependence of dislocation velocity for free dislocations moving into unstrained material can be represented by the empirical relation v=(τ/τ_0)^n, where v is the velocity, τ is the resolved shear stress and τ_0 and n are material constants. Inherent difficulties in obtaining direct displacement values have led to various suggestions for determining n by indirect methods.