The corrosion performance of magnesium alloy AM-SC1 in automotive engine block applications

The magnesium alloy AM-SC1 has been developed as a creep-resistant automotive engine block material. This paper outlines its corrosion performance under laboratory test conditions, considering corrosion on both the external and internal surfaces. This study found that AM-SC1 has a corrosion performance comparable to AZ91 when subjected to an aggressive salt-spray environment or in galvanic-coupling environments. This article further demonstrates that, with the appropriate selection of a commercially available engine coolant, the internal corrosion of AM-SC1 can be maintained at a tolerable level. In addition, internal corrosion resistance can be significantly improved by the addition of fluorides to the coolant solution. It is concluded that AM-SC1 can be successfully used in an engine environment provided that some simple corrosion-prevention strategies are adopted. For more information, contact Guangling Song, University of Queensland, Brisbane, Australia; +61 7 3365 4197; fax +61 7 3365 3888; e-mail g.song@minmet.uq.edu.au.