Alloying elements, effect calcium

In new research projects, non-combustible magnesium alloys are being developed. Investigations of the effect and mechanism of elements that may suppress the combustibility of magnesium are continuing. Calcium has been mentioned as an alloying element. 

Calcium is generated in situ for effecting reduction in another process in which elemental sodium is introduced in the charge mixture. The production of neodymium metal or of its alloys by the reduction of neodymium sesquioxide with sodium in the presence of calcium chloride is known as the NEOCHEM process. This process was developed at the General Motors Research Laboratories in the 1980s. The overall reaction pertinent to the process can be written as... 

In recent years, a number of Mg alloys have been tested under in vitro and in vivo conditions to understand their corrosion behaviour and mechanisms (Witte et al. 2006 Kannan and Raman, 2008, 2010 Kannan, 2010 Walter and Kannan, 2011). AZ series alloys show a lower corrosion current than that of pure Mg. However, aluminium-containing Mg alloys may not be the ultimate choice, simply because of the potentially toxic effects of high aluminium levels in body fluid. The influence on corrosion properties of calcium and rare-earth elements added to Mg and its alloys has been investigated, but the improvement was not significant. 

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