Influence of molybdenum ion implantation on the localized corrosion resistance of a high strength aluminium alloy

The effect of Mo+ implantation on corrosion properties of AA 7075 (T6 and T73) has been studied. The induced modifications in the surfaces have been analysed by XPS and GAXRD. EXCO tests and electrochemical DC and AC techniques have been used to characterize the localized corrosion resistance. The effect of implantation is highly dependent on the ageing conditions. A marked increasing of the impedance of T6 samples after implantation has been measured, while the effect of Mo on T73 samples is less clear. Impedance spectra allow analysing the differences in the evolution of localized corrosion between both tempers.

► Mo implanted 7075 aluminium alloy in T6 and T73 conditions is studied.
► After implantation Mo is not bonded to Al forming a new phase.
► Significant improvement in corrosion resistance of Mo implanted T6 alloy is detected.
► Limited effect or even harmful in the Mo-implanted T73 samples.
► Analysis of EIS spectra highlights induced changes in the corrosion mechanism.