Plastic Deformation

· The elastic energy per unit length for this straight edge dislocation is:
E_E= (Gb²/4π[1 - ν]) Ln(r₁/r₀) ~ Gb²
· For a straight mixed dislocation, the elastic energy is the sum of the edge and screw components
E_M= (Gb²/4πK) Ln(r₁/r₀) ~ Gb²
where (1/K) = (cos²θ+ sin²θ/[1 - ν]) , and θis the angle between the Burgers vector and the line vector of the dislocation.
· In addition to the elastic energy stored in the material, there is an energy due to the large atomic displacements in the "Core" of the dislocation i.e. the region r < r₀.
· The core energy can be computed from atomistic models of this region and has a value of about: E_Core = 1 eV/atom plane = 1.6 x 10^-10 J m^-1. This term is normally neglected compared to Gb².