Analysis of structural factors that control necking during tension of FCC metals and alloys

The relation between the strength and ductility of structural materials is theoretically analyzed using stress-strain curves for a number of fcc metals and alloys. The theoretical analysis is based on the criterion of necking in a tensile specimen and on a stress-strain curve, which reflects the evolution of the dislocation density in a material with increasing strain and the effect of structural factors on this evolution. Theoretical relationships are obtained for the uniform strain and the ultimate tensile strength. The effects of the stacking-fault energy, the solid-solution hardening, and the grain size on these quantities are considered.