Magnesium Surface Protection
Recent Investigations Into the Production of Corrosion-Resistant Films on Magnesium Alloys
(Journal of the Institute of Metals)
Considerable importance attaches to the surface protection of magnesium alloys, a subject about which little practical information is available. As a guide to future developments we give below an abridged report of recent interesting experiments carried out by two investigators.
This article first appeared in the Volume 5, Number 60 (October, 1943) issue of Aircraft Production magazine, and is presented here through the kind permission of Flight International. Thanks also to Bruce Vander Mark for furnishing volumes of Aircraft Production for scanning.
Magnesium is the most electropositive of the useful metals, and therefore it is hardly surprising to find that neither the metal nor the majority of the magnesium-rich alloys is particularly resistant towards corrosion. Compared with the light aluminium alloys, magnesium alloys are more susceptible to attack by the usual corrosive agencies; but this greater vulnerability is attributable to the poorer protective properties of the surface films normally present on the latter, and not to any difference between the inherent corrosion-resisting properties of the materials themselves. On atmospheric exposure, metallic magnesium, like aluminium, also develops a natural oxide film which is highly protective and usually confers a fair measure of resistance in rural and industrial environments. In marine atmospheres, however, or under conditions of immersion in water or acids, hydrofluoric acid being excepted, the natural film apparently affords little or no protection against attack.The remainder of this article is available only to AEHS Members. Please Login.