On the additivity of solid solution and dispersion strengthening

The superposition of solid solution and dispersion strengthening has been experimentally investigated for a copper-rich copper–gold solid solution dispersion strengthened by incoherent SiO2-particles. On the basis of the different temperature dependences of τt [total critical resolved shear stress (CRSS) of the simultaneously solid solution and dispersion strengthened single crystals], of τp [contribution of the SiO2-particles to τt], and of τs [CRSS of the binary copper–gold matrix solid solution] the superposition law τt(τs, τp) has been derived:τtk=τsk+τpk with k≈1.8.This result contrasts with Ebeling and Ashbyʹs (Phil. Mag. 13 (1966) 805) former one that k equals unity.