Corrosion of magnesium alloys in commercial engine coolants

Materials and CorrosionVolume 56, Issue 1 p. 15-23 Article Corrosion of magnesium alloys in commercial engine coolants G. Song, G. Song CRC for Cast Metals Manufacturing (CAST), Division of Materials, School of Engineering, The University of Queensland, Brisbane, QLD 4072, AustraliaSearch for more papers by this authorD. H. StJohn, D. H. StJohn CRC for Cast Metals Manufacturing (CAST), Division of Materials, School of Engineering, The University of Queensland, Brisbane, QLD 4072, AustraliaSearch for more papers by this author G. Song, G. Song CRC for Cast Metals Manufacturing (CAST), Division of Materials, School of Engineering, The University of Queensland, Brisbane, QLD 4072, AustraliaSearch for more papers by this authorD. H. StJohn, D. H. StJohn CRC for Cast Metals Manufacturing (CAST), Division of Materials, School of Engineering, The University of Queensland, Brisbane, QLD 4072, AustraliaSearch for more papers by this author First published: 13 January 2005 https://doi.org/10.1002/maco.200403803Citations: 51AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Abstract A number of magnesium alloys show promise as engine block materials. However, a critical issue for the automotive industry is corrosion of the engine block by the coolant and this could limit the use of magnesium engine blocks. This work assesses the corrosion performance of conventional magnesium alloy AZ91D and a recently developed engine block magnesium alloy AM-SC1 in several commercial coolants. Immersion testing, hydrogen evolution measurement, galvanic current monitoring and the standard ASTM D1384 test were employed to reveal the corrosion performance of the magnesium alloys subjected to the coolants. The results show that the tested commercial coolants are corrosive to the magnesium alloys in terms of general and galvanic corrosion. The two magnesium alloys exhibited slightly different corrosion resistance to the coolants with AZ91D being more corrosion resistant than AM-SC1. The corrosivity varied from coolant to coolant. Generally speaking, an organic-acid based long life coolant was less corrosive to the magnesium alloys than a traditional coolant. Among the studied commercial coolants, Toyota long life coolant appeared to be the most promising one. In addition, it was found that potassium fluoride effectively inhibited corrosion of the magnesium alloys in the studied commercial coolants. Both general and galvanic corrosion rates were significantly decreased by addition of KF, and there were no evident side effects on the other engine block materials, such as copper, solder, brass, steel and aluminium alloys, in terms of their corrosion performance. The ASTM D 1384 test further confirmed these results and suggested that Toyota long life coolant with 1%wt KF addition is a promising coolant for magnesium engine blocks. Citing Literature Volume56, Issue1January 2005Pages 15-23 RelatedInformation