The processes of energy dissipation and accumulation were studied during plastic deformation. In addition, the characteristics of strength and ductility were obtained for pure metals and structural materials pre-irradiated by neutrons or alternatively by alpha-particles. The temperature dependencies were obtained and analyzed for both strength and ductility characteristics and stored energy. It was found, that for the studied materials in their unirradiated and/or irradiated conditions, the stored energy increase correlates with the applied stress increase, i.e. E^s∼σⁿ, where n = 2 at early stages of deformation. Due to radiation effects the material, ability to accumulate mechanical energy decreases to a great extent with irradiating fluence increase. At the same time, heat release is increasing during deformation process.