Precipitate strengthening of non-spherical precipitates extended in 〈100〉 or {100} direction in fcc crystals

In precipitation strengthening of non-spherical precipitates, the effective radius is depending on the relative orientation between particle and the direction of dislocation movement. Expressions for the equivalent precipitate radius applicable to particle shearing and non-shearing mechanism are derived for ellipsoidal particles taking into account their growth direction and the dislocation character (edge and screw). The results are compared to spherical particles and presented in the form of closed analytical correction factors.