Plastic Deformation

Elastic interactions between dislocations: A Work Hardening mechanism.

· The long range, τ α (1/r), elastic stress field of a dislocation creates a force per unit length, τb, on other dislocations.
· Two parallel straight screw dislocations along the z-axis of an isotropic material with a shear modulus, G, are shown.

· The stress field at S₂ due to the dislocation S₁ at the origin is a function of r only:
τ_θz = Gb₁/2πr .
· The force per unit length on S₂ due to this stress is:
F_r = τ_θzb₂ = G b₁b₂ / 2πr