Transcripción del resumen del autor. The corrosion behavior of AZ31, AZ80, and AZ91D Mg-Al-Zn alloys coated with aluminum and Al-11Si thermal spray was evaluated in 3.5 wt% sodium chloride (NaCl) solution at 22°C by gravimetric and electrochemical impedance spectroscopy (EIS) measurements. The corrosion products were examined using scanning electron microscopy (SEM), energy-dispersive x-ray analysis (EDX), and low-angle x-ray diffraction (XRD). The as-sprayed aluminum and Al-11 Si coatings were porous, and galvanic corrosion of magnesium substrates was observed at the substrate/coating interfaces. Application of a cold-pressing posttreatment smoothed and densified the coatings, improved the contact between coating and substrate, and substantially increased the corrosion resistance. Cold-pressed aluminum coatings were an effective barrier against corrosion and revealed the same corrosion performance, regardless of the composition of the magnesium substrate. However, cold-pressed Al-11Si coatings were permeable to the chloride-containing solution, and galvanic corrosion of magnesium substrates was observed after a few days of immersion in 3.5 wt% NaCl solution.

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