Corrosion of neutron/gamma-irradiated aluminium alloy 6061

Effect of mixed neutron/gamma radiation on corrosion of aluminum alloy 6061 (AA6061) was studied. Square-shaped AA6061 samples were exposed to mixed neutron/gamma radiation continuously in the Thai Research Reactor-1/Modification 1 (TRR-1/M1), and gamma radiation from the Co-60 radiation source at the Gems Irradiation Center, Thailand Institute of Nuclear Technology (TINT). Dose-effect of the mixed radiation was investigated at neutron fluence and gamma ray of 1.7-3.9 × 10 n/cm and 218 kGy, respectively. For comparison, separate effect of gamma radiation on corrosion of AA6061 was also examined at the total dose up to 600 kGy. Characterization using SEM-EDX revealed that AA6061 exposed to the mixed radiation resulted in the development of amorphous-like corrosion products with no pitting corrosion observed, whereas exposing to gamma radiation assisted in pitting corrosion through the formation of crystal-like corrosion products (bayerite and boehmite).