Electroless Tin Plating on AA5052 Aluminum Alloy and Its Corrosion Resistance

A tin plating layer was prepared on the surface of AA5052 aluminum alloy by chemical immersion plating. The effects of sodium stannate content and plating solution pH on the morphology and structure of the coating were investigated by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). The effects of coating on the corrosion resistance of aluminum alloy were studied by immersion method and electrochemical method. The results showed that under alkaline conditions, tin could be plated on the surface of the aluminum alloy by chemical immersion plating. When the pH of the plating solution was 11.6 and the mass concentration of sodium stannate was 40 g/L, a uniform and dense metal tin plating layer was obtained. The presence of the coating significantly improved the corrosion resistance of the aluminum alloy in sodium chloride solution.