EFFECT OF RARE EARTH ELEMENTS ON CORROSION BEHAVIOR OF AM60 MAGNESIUM ALLOYS
稀土元素Ce和La合金化对AM60镁合金腐蚀行为的影响

The influence of rare earth(RE)element Ce and La addition on microstructure and corrosion behavior of AM60 magnesium alloy has been investigated.Microstructure of AM60-RE alloys was characterized by FESEM.The result indicated that γ phase with high content of rare earth element was found in AM60-RE alloys.The corrosion rate of AM60-RE alloys was evaluated by hydrogen evolution tests,in comparison with commercial AM60 magnesium alloy.The result indicated that the corrosion resistance of AM60 magnesium alloy can be improved by addition of Ce and La.The surface morphology and the compositions of corrosion product on AM60-RE and AM60 magnesium alloys after 10 days immersion in 3.5 wt% NaCl solution was examined respectively with FESEM and XRD.The XRD result showed that the corrosion product of the former alloys mainly consisted of oxides of Al and Mn and a little oxide and hydroxide of RE.The result of polarization measurements also clearly indicated that the corrosion resistance of AM60 magnesium alloys in solution containing Cl- ion can be improved by Ce and La addition.