Interplay of strengthening mechanisms in the interaction of a ½〈1 1 1〉 screw dislocation with Cr precipitates in bcc Fe: An atomistic study

The interaction of Cr precipitates with a ½〈1 1 1〉 screw dislocation in bcc Fe is studied using molecular static calculations to evaluate the contributions from different strengthening mechanisms. The total interaction energy of the precipitate and the dislocation, the surface energy created due to the precipitate shearing and the shear modulus misfit interaction energy were estimated separately. Based on these data the shear modulus misfit was concluded to be the main mechanism determining the precipitate resisting force for the passage of a ½〈1 1 1〉 screw dislocation.