Positron Annihilation Spectroscopy of the Accumulation of Vacancy Defects in an Aging Fe–Ni–Al Alloy Irradiated at 573 K

Abstract

The influence of intermetallic Ni₃Al precipitates on the accumulation of vacancy defects in aged Fe–Ni–Al alloy at the initial stages of electron irradiation (5 × 10^–4 dpa) at a temperature of 573 K has been studied using positron annihilation spectroscopy. The obtained results demonstrate that intermetallic precipitates inhibit the process of the accumulation of vacancy defects under irradiation. It has been found that these precipitates facilitate the mutual recombination of point defects that form under irradiation. This effect has been attributed to elastic stresses at the precipitate–matrix boundaries.