Strengthening of an L12-ordered γ′-intermetallic by disordered γ-particles. Part I: Computer simulations

Abstract Strengthening of an L1 2 -long-range ordered γ′-intermetallic by coherent disordered spherical γ-particles has been investigated by computer simulations and by measuring the critical resolved shear stress (CRSS) of Ni 69 Co 9 Al 18 Ti 4 . In the present Part I the simulations and their results are communicated, in Part II experimental data taken for Ni 69 Co 9 Al 18 Ti 4 will be reported. The simulations yielded numerical values for the CRSS τ p . The average radii r and the volume fractions f of the γ-particles have been varied widely: 1 nm≤ r ≤19 nm and 0.04≤ f ≤0.10. The numerical results τ p ( r ≥7 nm, f ) can be well represented by Friedel's relation—provided the dissociation of the dislocations into partial dislocations is allowed for in the calculation of the dislocation line tension.