Plastic Deformation of Polycrystalline Copper (Flow Stress)

Abstract

At a constant strain, the flow stress of polycrystalline copper is expressed as τ_f=τ_μ+k ·d^-1/2, where τ_f: flow stress, τ_μ: resistance force to gliding dislocations, k: ability of slip to propergation to an adjacent grain, and d: mean radius of grains.
In this paper, this equation is deduced theoretically from a piled-up dislocation model against grain boundaries, and the variations in k with strain, solute atoms, temperature and neutron irradiation are discussed. Furthermore, the stress-strain relation is obtained theoretically and decreasing of the rate of strain-hardening with increasing strain is explained.