轧制对ZM5镁合金腐蚀性能的影响

Influence of Rolling on Corrosion Behavior of ZM5 Mg-alloy

采用析氢、失重、电化学阻抗谱(EIS)、动态电位极化测试、XRD和SEM等方法对比研究了轧制前后ZM5镁合金腐蚀性能和微观组织的变化,并通过第一性原理分析研究了合金不同微观组织的电子功函数,探究轧制对ZM5镁合金腐蚀性能的影响。结果表明,轧制使ZM5发生明显的择优取向,轧制后ZM5的腐蚀失重、析氢量都显著下降,而极化电阻明显上升,表明轧制态镁合金的耐蚀性优于铸造镁合金。模拟计算结果表明α相的重排提高了轧制合金的电子功函数。

The corrosion performance and microstructure of ZM5 Mg-alloy before and after rolling were comparatively studied by hydrogen evolution measurement,mass loss method,electrochemical impedance spectroscopy(EIS),dynamic potential polarization measurement,XRD and SEM.The electron work function of different microstructures was numerically simulated through first principle analysis.The results show that rolling causes an obvious preferred orientation for ZM5 Mg-alloy.The corrosion mass loss and hydrogen evolution of ZM5 Mg-alloy decrease significantly after rolling,while the polarization resistance increases obviously.These all indicated that the corrosion resistance of the rolled ZM5 Mg-alloy is better than that of the cast one.The simulation results show that the rearrangement ofα-phase enhances the electronic work function of the Mg-alloy.