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Corrosion resistance coating of ZK60A -T6 Magnesium alloy

Which is the most effective corrosion resistance coating for sea water environment on ZK60A-T6 magnesium alloy? Conversion coating or organic coating is preferred?

Biren Desai
Manufacturing - Mumbai
2005

I would suggest HAE anodising, probably followed by a clear coat varnish. Pretty harsh environment for magnesium, there are not any easy answers, my suggestion tries to avoid the use of hexavalent chromium due to its environmental impact.

Brian Terry
Aerospace - Yeovil, Somerset, UK
2005

As Mr. Terry stated, starting with an anodizing treatment is a good idea for maximizing the corrosion resistance. One application of a magnesium helicopter transmission housing started with a plasma electrolytic oxidation process (modification of HAE anodizing), followed by 3 separate coats of phenolic to seal the porosity in the anodic layer. This is subsequently followed by a high quality organic paint treatment consisting of an eopxy primer followed by a polyurethane topcoat. The resultant coating system will be very thick, and is capable of providing excellent corrosion resistance.

Toby Padfield
Automotive module supplier - Michigan
2005