This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
The Magnesium Hatchback of the 3-Liter Car: Processing and Corrosion Protection
Technical Paper
2000-01-1123
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Event:
SAE 2000 World Congress
Language:
English
Abstract
The hatchback of Volkswagen's 3 liter car (3 l fuel consumption per 100 km) consists of an inner component of die casting magnesium (AM50) covered with an aluminum panel from the outside. This hybrid design requires a new manufacturing process: The pre-coated magnesium part will be bonded and folded with the bare aluminum part. Corrosion protection is provided by an organic coating system which both protects against general corrosion and galvanic corrosion.
The corrosion of the Al / Mg sandwich has been examined with hybrid samples which are similar to the hatchback. Several powder coatings (epoxy resin, polyester resin, hybrid resin), wet paints and cathodic electro-coating paints of different thicknesses and compositions have been applied to the magnesium part. They show that only powder coating provides adequate protection. Galvanic corrosion at the points of attachment of the hatchback might be possible (for example the bolted joint of the hinge). Resistance against galvanic corrosion has been tested with samples that had a damaged paint coat in order to simulate a defect. Furthermore different contact elements (Fe, Al, Zn, etc.) have been attached with electrically conductive fixings. Under laboratory conditions, all test samples where subjected to a corrosion load of 30 cycles in the environmental corrosion test.
Recommended Content
Technical Paper | Non-Chromate Conversion Coatings for Magnesium Die Castings |
Technical Paper | MAGPASS-COAT ® as a Chrome-free Pre-treatment for Paint Layers and an Adhesive Primer for Subsequent Bonding |
Technical Paper | Magnesium in the Volvo LCP 2000 |
Authors
Topic
Citation
Schreckenberger, H., Papke, M., and Eisenberg, S., "The Magnesium Hatchback of the 3-Liter Car: Processing and Corrosion Protection," SAE Technical Paper 2000-01-1123, 2000, https://doi.org/10.4271/2000-01-1123.Also In
References
- Hawke, D. Gaw, K. “Effects of Chemical Surface Treatments on the Performance of an Automotive Paint System on Die Cast Magnesium” SAE Technical Paper, 920074 Detroit 1992
- Murray, R.W. Hillis, J.E. “Powder Coatings on High Purity Die Casting Magnesium For Appearance and Protection” 16th International Die Casting Congress and Exposition Detroit 30 Sept. 3 Oct 1991 North American Die Casting Association Illinois 1991
- Avedesian, M.M. Baker, H. “Magnesium and Magnesium Alloys” ASM Specialty Handbook ASM International USA 1999
- Schreckenberger, H. Laudien, G. “Processing and corrosion control of a magnesium body structure element” Proceedings of the Euromat 99 München 1 Wiley-VCH Weinheim (Germany) 2000
- Haferkamp, H. Niemeyer, M. Tai Phan-tan Kaese, V. Schreckenberger, H. Laudien, G. Koeppen, H.-J. Lehmhus, D. “Oberflächenschutzsysteme für die Verschraubung von Magnesiumbauteilen” Magnesiumguss Abnehmerseminar u. Automotive Seminar Aalen (Germany) 30 Sept. 1 Oct 1998 IMA 3-932291-16-6 1998