α-particle irradiation induced precipitation and phase instability in concentrated Fe-Cr-Ni alloys

Resistivity annealing of three different Fe-Ni-Cr alloys was investigated after α-particle irradiation at 320 K. In order to obtain a correlation between resistivity behaviour and microstructural changes, TEM studies were performed after specific annealing temperatures. The main resistivity changes can be explained in terms of radiation enhanced nucleation and growth of precipitates. After α-irradiation and annealing black-white contrast images could be observed by TEM. Up to annealing temperatures of 800 K these images were attributed to vacancy loops and/or precipitates. The defect images which remain after annihilation at about 850 K are attributed to precipitates with uniaxial strain in <111> directions and with negative misfit volume. (author)