Kinetics and evolution of corrosion failure of pure magnesium with various grain sizes: in-situ study

Abstract

During the recent years, magnesium and its alloys have achieved the increasing interest. Magnesiumalloys are the promising material for aircrafts and other transport because of low density andhigh engineering strength. Moreover, the biodegradable medicine implants used for osteosynthesiscan be made of magnesium which is able to resorb in the human body without health harming.The corrosion process of magnesium is featured by many debatable issues. For example, the effectof the grain size on the corrosion kinetics has not been reported as yet. In this paper the kineticsand staging of the corrosion process of technically pure magnesium with different grain sizewere investigated with the use of the modern in-situ techniques including real time video-monitoringand corrosion rate measurements by hydrogen evolution. It is established that the corrosionrate of coarse-grained magnesium is significantly higher than that of fine-grained magnesium, thatis presumably due to the different corrosion resistance of the individual grains with different crystallographicorientations. The kinetics of corrosion processes for both materials has been established.The graphs of the change in the corrosion rate during the experiment have been plotted andthe evolution of corrosion damage has been shown.