A continuum model of tensile fracture of solid metals is formulated for the cases of pure aluminum and D16 alloy. It is verified within a wide range of strain rates using results of molecular dynamics simulations and known experimental data. The model considers the growth of spherical voids driven by plastic deformation in their vicinities. Both thermofluctuation nucleation of new voids and growth of the pre-existing ones are considered. The stress concentration areas near inclusions are taken into account in the case of alloy. The model is applied to description of the back-side spallation of metal targets exposed to the shock wave loading initiated by high-velocity impact; calculations are performed in 1D case. Results of comparison with known experimental back surface velocity histories are presented.