Chemically-biased diffusion and segregation impede void growth in irradiated Ni-Fe alloys

•Chemically-biased diffusion creates Ni segregation near mobile defect sinks in Ni-Fe alloys.•Segregation profiles near voids and interatitial loops suppress their interaction with vacancies.•Interstitial loops grow while void nuclei collapse into Ni-rich precipitates in the damage region.•Ni segregation on voids and interstitial loops lead to Ni depletion of the matrix between sinks.•Vacancies migrate out and form voids beyond the damaged area, inaccessible to SIAs.