Session 7: Decorative Automotive Considerations
Offers an introduction to a low-voltage, non-toxic PEO coating technology for application to magnesium. Cirrus Mg Defender™ is a novel surface finishing technology that provides thin, adherent, and durable protection for magnesium and its alloys at low cost with an exceptionally low energy and environmentally sustainable process. The process presented also has applications for aluminum and titanium substrates.
Advances in Surface Finishing Technology
The need for energy efficiency, emission reduction and improved performance necessitates the development of lighter automotive and aerospace components. Light metals, such as Magnesium, are essential to reducing weight; however, Mg and its alloys require protective surface finishes to prolong their service life. Conventional magnesium coatings technologies are energy intensive and often require toxic chemicals, such as fluorine compounds. Widespread use of magnesium alloys in high performance applications requires low cost, efficient and environmentally sustainable surface finishes.
A recent surface finishing innovation from Cirrus Materials Science, Mg Defender™, offers a sustainable magnesium coating technology that reduces the cost, energy consumption, and coating thickness required to protect magnesium components. Cirrus Mg Defender™ employs a proprietary low voltage Plasma Electrolytic Oxidation (PEO) process to deposit a tightly bonded protective layer to any magnesium surface. Cirrus Mg Defender™ operates at less than 5% of traditional PEO process power while producing a surface that provides outstanding corrosion protection. Doping the Mg Defender™ bath with either carbon and/or nitrogen compounds which, under the influence of the arc temperatures introduce carbides and/or nitrides directly into the developing surface, achieves surfaces with higher hardness (>875HV) and greater wear resistance. Mg Defender™ surfaces also support direct deposition of secondary functional coatings including electro or auto catalytic metallic coatings and electro deposited or traditional polymer surfaces, which tightly interlock to the PEO surface producing outstanding adhesion. Such secondary layers can provide important functional characteristics, including electrical conductivity, wear resistance, lubricity and/or decorative aspects, which support a plethora of applications. The presentation provides an update on this novel magnesium coating technology which extends the opportunities for magnesium applications.