Microstructure and corrosion behaviour of Mg-1Sc alloy with different processing conditions

The microstructure and corrosion resistance of Mg-1Sc alloys in different processing conditions were investigated. The composition was examined by Inductively Coupled Plasma Atomic Emission Spectrometer, the microstructure was analyzed by metallographic microscope. The corrosion behaviour of the alloy was investigated by hydrogen evolution tests and electrochemical tests. The results showed that as-cast and rolled Mg-1Sc possess better corrosion resistance compared with extruded Mg-1Sc alloys, which is due to the fact that the extrusion flow lines and residual stresses caused by machining in extruded Mg-1Sc alloys can lead to easier corrosion. In addition, rolled Mg-1Sc alloy shows better corrosion resistance than as-cast alloy, which is attributed to the finer grain sizes and a denser corrosion product film.