Accelerated degradation rate of AZ31 magnesium alloy by copper additions. Issue 6 (2nd January 2018) - Zhou, Miao
Abstract : Corrosion property of AZ31‐ x Cu ( x = 0, 0.5, 1.5, 3 wt%) alloys has been investigated using scanning electron microscope (SEM) equipped with energy dispersive spectroscope (EDS), X‐ray diffractometer (XRD), immersion tests, and electrochemical measurements. The results indicate that the content of AlCuMg phase, main secondary phase in the Cu‐containing alloys, is positively dependent on copper concentration. Acceleration of corrosion rate is found in Cu‐containing alloys due to micro‐galvanic corrosion. AlCuMg phase acts as micro‐galvanic cathode against anodic magnesium matrixes. In this regard, the degradation rate is decreasing in the following order: AZ31‐3Cu > AZ31‐1.5Cu > AZ31‐0.5Cu > AZ31. Abstract : Hydrogen evolution test and electrochemical impedance measurements are used to evaluate the corrosion rates of AZ31‐ x Cu ( x = 0, 0.5, 1.5, 3 wt%) alloys. Hydrogen liberation is positively dependent on Cu content. It was found that the degradation rate is decreasing in the following order: AZ31‐3Cu > AZ31‐1.5Cu > AZ31‐0.5Cu > AZ31.