Effect of adding Y and Ce on corrosion behaviour of the extruded ZK60 magnesium alloy

Abstract

The effect of rare earth elements Ce and Y addition on microstructure and corrosion behaviour of an extruded ZK60 magnesium alloy was investigated. Materials characterisation was performed using a scanning electron microscope and X-ray diffraction. Corrosion behaviour of ZK60 and ZK60-3x (x = Ce, Y) alloys were evaluated using electrochemical impedance spectroscopy and potentiodynamic polarisation test. At the end of evaluations, the best corrosion performance was observed for the ZK60 base alloy, due to its microstructure consisting of larger grains and lower volume fraction of second phase particles. On the other hand, the two other alloys suffered from galvanic corrosion rising from their RE-containing particles and the more fraction of high energy grain boundaries acting as possible areas for corrosion initiation.