Effect of Nd on the corrosion behaviour of AM50 and AZ91D magnesium alloys in 3.5wt. NaCl solution

摘要

The corrosion performance of AM50 and AZ91D alloys containing up to 1.5wt.% Nd was investigated by electrochemical and gravimetric measurements in 3.5wt.% NaCl at 22°C. The alloys were characterized by scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD) and surface potential maps. In Nd-containing alloys, formation of Al 2Nd and Al-Mn-Nd intermetallic compounds reduced the volume fraction and modified the morphology of the β-Mg 17Al 12 phase. The addition of Nd improved the corrosion resistance of the alloys due to increased passivity of the surface film and suppression of micro-galvanic couples. © 2011 Elsevier Ltd.