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Effects ofγ-irradiation and deformation temperature (T)on the tensile properties of Pb-2 mass% Sb alloys were studied.The samples were annealed at 458 K for 2 h in air,then water quenched after they wereγ-irradiated (the different doses were 0·5,1·0,1·5,and 2·0 MGy).The tensile properties were performed using stress-strain measurements at a constant strain rate (1·2×10-3 s-1 )and at different T (303-393 K).It was found that at con-stant dose,the fracture stress (σF )decreases while the fracture strain (εF )increases as T increases.At particular T,σF increases whileεF decreases with increasing dose.The strain-hardening exponent (n),which is the slope of the relation between ln(σ)and ln(ε)of the parabolic part of the stress-strain curve,was determined and its values in-crease as T increases and decrease as the dose increases.The value of the activation energy increases as the dose in-creases from 0·07 eV for un-irradiated sample to 0·1 eV for the 2 MGy-irradiated sample.These values are in ac-cordance with that needed for dislocation movement and ordering process.An interpretation of the results was given, based on the creation of point and line defects due toγ-irradiation,and that results in a distribution of beta phase (Sb-phase),leading to a difficulty in the movement of dislocations,so there is an increase in alloy hardness.