Abstract
Paper deals with the evaluation of surface treatment of Mg-2Al-1RE magnesium alloy on its electrochemical behaviour in 0.1M NaCl solution. The surfaces of the magnesium alloy specimens were treated mechanically by grinding and shot-peening using glass-balls blasting tools and electrochemically using zinc-phosphating. The surfaces after grinding, grinding + phosphating and grinding + shot-peening + phosphating were evaluated using electrochemical impedance spectroscopy method in combination with immersion tests up to 168 hours of exposition. The measured impedance spectra (as Nyquist plots) were analysed using various equivalent circuits. It was observed that shot-peening pre-treatment increases the corrosion resistance of phosphate surface in comparison with only grinded and phosphate surface.