Monash University, Australia, announces that a research team has discovered that adding 0.37% arsenic to magnesium reduces the corrosion rate significantly. Mass loss following seven days of immersion in 0.1M NaCl was 1.75 x 10-4 g/cm3/day for pure magnesium, but only 0.5 x10-4 g/cm3/day for Mg-0.37wt.% As. The addition of very low levels of arsenic to magnesium retards the corrosion reaction by effectively ‘poisoning’ the reaction before it completes.
The research team was led by Monash University’s Associate Professor Nick Birbilis. Other researchers participating in the effort were from the University of Wales and CSIRO.
“This is a very important and timely finding. In an era of light-weighting for energy and emissions reductions, there is a great demand for magnesium alloys in everything from portable electronics to air and land transportation,” Associate Professor Birbilis said. “Magnesium products are rapidly evolving to meet the demands of industry, but presently are hindered by high corrosion rates. The arsenic effect we discovered is now being trialled as a functional additive to existing commercial alloys.”
