Characterization of Film Formation on Magnesium Alloys due to Corrosion in Engine Coolants

This study utilized Rutherford Backscattering Spectroscopy (RBS) and Auger Electron Spectroscopy (AES) to determine the thickness and composition of corrosion films formed on magnesium alloys exposed to experimental engine coolants intended for use with creep-resistant magnesium alloy engine blocks. Knowledge on the nature of the film formed may produce a better understanding of corrosion inhibition and protection requirements for these materials. This paper will first briefly review the RBS and AES techniques as applied to the characterization of surface films on metals. It will then present results from experiments conducted with pure magnesium and two different magnesium alloys in two engine coolants.