Evolution of Corrosion Resistance in the LAE442 Magnesium Alloy Processed by ECAP

The influence of processing by equal channel angular pressing on the corrosion resistance was investigated in the extruded LAE442 magnesium alloy by the linear polarization method. Continuous increase of the corrosion resistance with the increasing number of passes was measured. The polarization resistance of the 12P sample was substantially higher as compared to the extruded state. The results were discussed in terms of the corrosion layers formed on the surface after seven days of immersion. It was concluded that the substantial increase of polarization resistance was caused by the combined effect of grain refinement and aluminum and lithium oxides formation within the corrosion layer.