Title:
Novel Magnesium Pretreatment Coatings Offering Excellent Corrosion Protection
Description:
Magnesium alloys show promise for automotive, industrial and aerospace applications due to their low density, high strength-to-weight ratio, good machinability and low cost. These alloys have the potential to lighten cars and aircraft, reducing fuel consumption and emissions. A major drawback to the use of magnesium alloys is their highly reactive nature and tendency to corrode. As a result, most existing pretreatment systems for these alloys require the use of chromium, which is increasingly coming under regulatory pressure, as a corrosion inhibitor. Through a project funded by the Department of Energy and administered by the U.S. Automotive Materials Partnership (USAMP), PPG developed chromium-free metal pretreatment solutions for ZEK-100 and AZ21 magnesium alloys, coupled with tin-free electrocoat. In a major technical advance, several chromium-free cleaning and pretreatment processes were developed that offer excellent corrosion protection when compared to a typical automotive pretreatment systems. These pretreatment solutions were optimized for use in multi-metal applications: compatibility with magnesium and other metals was demonstrated without the need for additional process steps.
Abstract:
Magnesium alloys show promise for automotive, industrial and aerospace applications due to their low density, high strength-to-weight ratio, good machinability and low cost. These alloys have the potential to lighten cars and aircraft, reducing fuel consumption and emissions. A major drawback to the use of magnesium alloys is their highly reactive nature and tendency to corrode. As a result, most existing pretreatment systems for these alloys require the use of chromium, which is increasingly coming under regulatory pressure, as a corrosion inhibitor. Through a project funded by the Department of Energy and administered by the U.S. Automotive Materials Partnership (USAMP), PPG developed chromium-free metal pretreatment solutions for ZEK-100 and AZ21 magnesium alloys, coupled with tin-free electrocoat. In a major technical advance, several chromium-free cleaning and pretreatment processes were developed that offer excellent corrosion protection when compared to a typical automotive pretreatment systems. These pretreatment solutions were optimized for use in multi-metal applications: compatibility with magnesium and other metals was demonstrated without the need for additional process steps.
Type:
Learning Station VI: Corrosion and Technology