Irradiation-induced defects in solid solution and intermetallic compounds of the Ni-Al system : the effects of a third element (Ti or Ta)

Abstract
The effects of low-temperature electron irradiation experiments and of subsequent annealing treatments were investigated by means of residual resistivity measurements in model alloys based on the Ni-Al system. The materials, representing the two constituent phases of technological Ni-based superalloys, were a Ni(Al,Ti) solid solution and three intermetallics Ni₃Al, Ni₃(Al,Ti) and Ni₃(Al,Ta). The presence of the additional elements Ti or Ta had an important influence both in the solid solution and in the intermetallic compounds. These elements were found to interacte strongly with the irradiation-induced defects, reducing significantly their mobility via a trapping effect. Such a result could explain, at least in part, the self-diffusion retardation found in the same materials by means of ordering kinetics studies.