Topic: Review of recent research on Mg alloys with low corrosion

Speaker: Prof. Andrejs Atrens

               The University of Queensland (UQ)

Time: 10:00-11:00, (Tue.) Aug. 27 , 2019

Venue: Room 403, Shi Changxu Building, IMR CAS

Prof. Andrejs Atrens: is a Professor of Materials at The University of Queensland (UQ), where he has been since 1984. He was awarded DEng (a higher doctorate) in 1997 by UQ, and became Fellow of the Higher Education Academy in 2018.An international academic reputation is evident from invitations for keynote papers at international conferences (25 since 2004), invitations as guest scientist/visiting professor at leading international laboratories (in China, Switzerland, Germany, Belgium, France & Sweden, 27 months since 2003), a ISI H-index of 54 [web of science] (66 [Google scholar]), many citations (13,610 citations [web of science]; 19,094 [Google scholar]), 23 journal papers with more than 100 citations, 10 journal papers with more than 200 citations, and an excellent publication record in top international journals with more than 280 refereed journal publications.

Abstract:

Twenty years ago stainless Mg was a research goal, and this goal remains relevant today. Most research has studied Mg corrosion in aqueous solutions, particularly in concentrated chloride solutions, because these are expected to provide information relevant for the corrosion of Mg in auto applications and for aerospace usage. It should also however be noted that Mg alloy corrosion in the atmosphere can be much less, for example the atmospheric corrosion rate can be lower than the common aluminium alloys or steel. The main metallurgical factors controlling corrosion of Mg alloys in aggressive chloride environments were clear: (i) corrosion acceleration by micro-galvanic corrosion by second phases, including Fe-rich phases, (ii) improved protectiveness of the surface film on the alpha-Mg matrix by alloying, and (iii) decreased corrosion rate by microstructural refinement. These factors remain the metallurgical factors of importance for Mg corrosion. Over the last twenty years, there has been much research carried out with the aim of producing Mg alloys with low corrosion rates. The bench mark is the intrinsic corrosion rate of Mg of  ～0.3 mm/y in a concentrated chloride solution and in a synthetic body fluid like Hanks’ solution. It should be mentioned that the corrosion mechanistic insights from the studies in concentrated chloride solutions are also relevant to the biocorrosion of Mg. This paper reviews the recent research on Mg alloy development and focusses on Mg alloys with low corrosion rates that are comparable to, or lower than, the benchmark of the intrinsic corrosion rate of high-purity Mg.