DISLOCATION KINETICS DURING PLASTIC DEFORMATION OF TWO-DIMENSIONAL POLYCRYSTALS

The dislocation-kinetic approach is applied to the study of plastic flow of plate specimens of two-dimensional polycrystals of high purity metals under uniaxial tension with a constant strain rate at moderate temperatures. A dislocation-kinetic equation is formulated. It takes into account the role of the free surface of a plate specimen, which is the source and sink of dislocations, and the strengthening effect of through grain boundaries in a two-dimensional polycrystal. To calculate tensile stress-strain curves, the kinetic equation was transformed using the Taylor strain hardening law and an analytical solution was obtained for this equation. Using the example of plate specimens of two-dimensional polycrystals of high purity aluminium (99.999 at.%) it was shown that the calculation results are in good agreement with experimental data.