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

Strengthening of an L12-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 Ni69Co9Al18Ti4. In the present Part I the simulations and their results are communicated, in Part II experimental data taken for Ni69Co9Al18Ti4 will be reported. The simulations yielded numerical values for the CRSS τp. 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 τp (r≥7 nm, f) can be well represented by Friedelʹs relation—provided the dissociation of the dislocations into partial dislocations is allowed for in the calculation of the dislocation line tension.