Increased specific resistivity of grain boundaries in nonequilibrium state in ultrafine-grained Al–Cu–Zr alloy

In this work an Al–Cu–Zr alloy with ultrafine-grained (UFG) structure formed by high-pressure torsion is studied. Different structural states of grain boundaries in the UFG structure were achieved through subsequent annealing and additional deformation. The specific resistivity of the alloy in the temperature range 77–300 K has been experimentally determined for each state. Based on the microstructural parameters of the alloy, analysis of changes in average specific resistivity of grain boundaries was carried out. It is shown that additional deformation, which introduces excess grain boundary dislocation density (nonequilibrium state), leads to its increase by $\ge$ 20%.