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The precipitation hardening in Ni-based superalloys, which contain up to 73% volume fraction of cubic coherent γ′ precipitates in γ matrix, has been investigated by three-dimensional parametric dislocation dynamics. Dislocations glide under external stress on a (111) slip plane intersected by cubic γ′ precipitates. The critical resolved shear stress (CRSS), the stress to drive dislocations through precipitates, is evaluated for variations in various microstructural parameters: γ′ volume fraction, anti-phase boundary (APB) energy and γ channel width (i.e., precipitate/particle spacing). It is shown that the CRSS depends on the square root of the APB energy while being linearly proportional to the volume fraction of γ′. A microstructure with a non-uniform size distribution of γ′ has a CRSS that is 20–30% smaller than that of a microstructure with a uniform γ′ size of the same value as the average γ′ size in the non …