Surface properties and protection of magnesium alloys

Authors

  • Pietro Luigi Cavallotti

Abstract

Passivity in aqueous solution of Magnesium and its alloys and the possibility of obtaining corrosion resistant coating onto them depend on this element electrokinetic behaviour: Magnesium is much more active than the other light metals Aluminium and Titanium. This general behaviour is related to a parameter of electrochemical electronegativity for metals in aqueous solutions, the Normality-Inertia parameter PNr A high value ofPNi corresponds to inertia with high overvoltages for metal ion exchanges and low overvoltages for hydrogen exchange at the electronic surface; low PM values correspond to normality with reverse behaviour. The approach is extended to other reactions: oxide, sulphide, fluoride and chloride formation and related to the stability of fluorides at the Magnesium surface. The interpretative scheme is applied to corrosion and protection of the Magnesium alloys.

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Published

2013-09-02

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Section

Articles