Displacement threshold energies in Ni(Al) solid solutions and in Ni 3Al

Abstract

Resistivity damage rates, determined during low-temperature electron irradiations in the energy range 0.3–2.5 MeV, were used for evaluating displacement threshold energies of nickel and aluminium in pure nickel, short-range ordered Ni-6 at% Al and Ni-10 at% Al solid solutions, and in long-range ordered Ni 3Al. These parameters were deduced from a comparison of normalized experimental displacement cross-section variations as a function of electron energy, with theoretical curves based on a displacement model for diatomic materials. The threshold energy of nickel is about the same in the three investigated alloys ( T d Ni = 23 ± 2 eV) as in the pure metal. The threshold energy of aluminium T d Al is of the same order as T d Ni in the Ni(Al) solid solutions (22 ± 2 eV) but it is larger in the long-range ordered Ni 3Al: 30 ± 2 eV.