Categories: Press Releases Date: Dec 5, 2006 Title: High purity magnesium alloys by themselves are actually pretty resistant to corrosionHigh purity magnesium alloys by themselves are actually pretty resistant to corrosion
High purity magnesium alloys by themselves are actually pretty resistant to corrosion. For this reason, magnesium is an excellent material selection when lightweight, high strength and stress failure resistance are primary design factors. However, as with most metals, magnesium will oxidize when exposed to the atmosphere. And it’s when inadequately protected magnesium alloys are subjected to aggressive operating environments or poor assembly practices do we experience severe corrosion and premature failure of the component. For these reasons, it is important to follow a suitable protection scheme when working with magnesium.
Hard anodizing ( Dow 17) can be applied to all magnesium alloys and provides a thick abrasive resistant surface. However, anodizing alone provides only a minimal level of protection from corrosion due to its inherent porosity. The best practice is to coat the anodized product with a water impermeable resin. The resin coating should be applied as soon as possible after the Dow application has been completed.
Because of a surface build up inherent with anodizing, it isn’t always practical to apply Dow 17 to surfaces that are machined to a dimensional tolerance. For this situation, conversion coating with Dow 7 is an excellent alternative. Conversion coatings such as Dow 7, offer an excellent base for paint to adhere to without affecting machined dimensions. As with anodizing, it is extremely important to apply a durable resin coating as soon as possible after Dow 7 in order to achieve the best corrosion protection possible.
PTI maintains close relations with several local facilities, which are approved to apply resin coatings on magnesium. All of our approved sources are capable of applying these coatings within as little as eight hours from the application of our Dow products, providing our customers with the best protection scheme available. With over two decades of magnesium coating experience PTI provides customers with superior service, turn time and technical support.