This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
A New Paint-Bake-Hardenable Aluminum Alloy for Auto Body Sheet Applications
Annotation ability available
Sector:
Language:
English
Abstract
A new 5xxx-series aluminum alloy, which was designed to have an excellent paint-bake-hardenability with practically no room-temperature aging, has been developed for automobile body sheets. The alloy contains 2∼3%Mg with additional amounts of Cu and Si. Yield strength in the as-shipped condition is very low, 80∼100MPa, but it can be increased by as much as about 60MPa through 2% stretch and paint-bake at 170°C. Such an excellent response to paint-bake was revealed to result from Guinier-Preston-Bagaryatskii(GPB) zone formation and enhanced by the optimum addition of Si. Density of vacancies in the alloy was reduced through a special annealing process to suppress room-temperature aging.
Press-forming for fender outer and engine hood inner panels was done, and the alloy was demonstrated to have formability superior to 6xxx-series alloys and Al-4.5%Mg alloys, due to the reduced initial yield strength which also suppressed susceptibility to spring back. High bake-hardenability successfully provided sufficient dent-resistance in the paint-baked panels. Spot weldability was proved much better than Al-4.5%Mg and Al-5.5%Mg alloys due to lower Mg content of the alloy. Zinc phosphating performance was almost equal to other aluminum alloys. The cost advantage was also obtained mainly through better workability and higher material yield against other aluminum alloys with higher Mg content.
Recommended Content
| Technical Paper | Considerations about the Aluminium Dispersion Strengthened Alloy |
| Technical Paper | Dynamic Denting Study of Aluminum Alloys |
| Aerospace Material Specification | Aluminum Alloy, Structural Shapes, Extruded, 6061 |
Authors
Topic
Citation
Fujita, T., Hasegawa, K., Mitao, S., Niikura, M. et al., "A New Paint-Bake-Hardenable Aluminum Alloy for Auto Body Sheet Applications," SAE Technical Paper 950719, 1995, https://doi.org/10.4271/950719.Also In
References
- Uno T. Baba Y. Terai S. Development of new 5xxx-series aluminum alloy for auto body sheet Int Leichtmetalltag 19 1981 358
- Evancho J. W. Kaufman J. G. New 6XXX series alloys for auto body sheet Aluminium 53 10 1977 609
- Hunt, W.H. Jr. Willett G.H. A Study of the Technical and Economic Aspects of Artificially Aging Aluminum Automotive Alloys SAE Paper No. 810822 Detroit June 1981
- Fortin P.E. Bull M.J. Moore D.M. An Optimized Aluminum Alloy (X6111) for Auto Body Sheet Applications SAE Paper No. 830096 Detroit February 1983
- Anderson W. A. Blackburn R. D. Shabel B. S. Development of aluminum alloys for body sheet Aluminium 50 12 1974 775
- Komatsubara T. Matsuo M. New Al-Mg-Cu Alloys for Autobody Sheet Applications SAE Paper No. 890712 Detroit February 1989
- Yoshihara N. Araki K. Fukumoto H. Furubayashi T. JOURNAL OF THE JAPAN SOCIETY FOR TECHNOLOGY OF PLASTICITY 36 1995