Solid-solution hardening by point-like obstacles of different kinds

Abstract

The critical resolved shear stress (CRSS) for a dislocation percolating through penetrable obstacles with different pinning strength is derived analytically. The stability of dislocation–obstacle configurations is determined by evaluating the configurational entropy. The analytical results imply a superposition law for the concentration of pinning obstacles on the dislocation line, and a Pythagorean-type hardening rule for the CRSS when obstacle strengths are weak and nearly the same. For comparison with derived results, discrete dislocation dynamics simulations are performed for irradiated iron.