Abstract:
For low-angle tilt boundaries formed by dislocation walls of straight edge dislocations in slip systems $\langle$111$\rangle$$\{110\}$ and $\langle$111$\rangle$$\{112\}$, the sink strengths for self-point defects (vacancies and self-interstitial atoms) and the bias factors (relative difference in the sink strengths for self-interstitial atoms and vacancies) have been calculated in BCC metals Fe and V. The calculations have been performed using the object kinetic Monte Carlo method in the temperature range 293–1000 K, the subgrain misorientation angles 1.5–10$^\circ$ and the subgrain sizes 150–900 $a$ ($a$ is the lattice parameter). The elastic interaction of self-point defects in stable and saddle-point configurations (elastic dipoles) with the elastic fields of dislocation walls has been calculated by means of the anisotropic theory of elasticity (metals Fe and V differ significantly in the elastic anisotropy ratio). The sink strengths of low-angle boundaries do not depend (within the calculation accuracy) on their type (the slip system of dislocations). The bias factor value varies with temperature in the range of 15–30% and is inversely proportional to the misorientation angle and the size of the subgrains. The bias factors in Fe and V are significantly different (for V it is several times less).
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