The elemental profiles along the a-axis and across the dislocation (Figure 7a) showed the accumulation of Ca and deficiency of Fe at the Cpx at the dislocation, consistent with the substitution of Ca for Fe in the Cpx structure (Figure 7b).
The time delay between these two states, which is determined by the average dislocation velocity and pillar diameter, leads to plastic strain oscillations and intermittent dislocation avalanches, consistent with experimental observations.
Additional simulations conducted to assess the impact of defect parameters revealed a weak dependence of the dissolution rate on dislocation density, consistent with previous experimental observations.
The indicated axes are b parallel to directions and a parallel to directions. it means that a 98% of the lattice mismatch is accommodated by the misfit dislocation network, consistent with the result obtained from moiré fringes.
Studies of dislocations under applied load reveal marked difference in mobilities of the screw and edge dislocations that are consistent with experimental observations.
Our ab initio results allow for an evaluation of the inter-row model, which is found to produce dislocation-core structures consistent with DFT results, but fails to describe the dislocation movement in these alloys.
The retention of equiaxed grain shapes during dislocation creep is consistent with a model based on local recovery related to the disturbance of triple junctions.
Results over a wide range of H concentrations sufficient to generate a range of sizes in the Cottrell atmospheres show that the Cottrell atmospheres follow the moving dislocations, leading to a resistance to dislocation motion that is consistent with solute drag theory; thus, H reduces the dislocation mobility.
At the second scale, a novel meso-scale simulation (MSS) redistributes the mobile part of the dislocation density within grains consistent with the plastic strain, computes the associated inter-dislocation back stress, and enforces local slip transmission criteria at grain boundaries.
Careful plane determinations and dislocation analyses are not consistent with a glide and cross-slip mechanism.
