Specific Mechanical Properties of Superplastically Formed Components and Resulting Applications for Vehicles

Abstract:

The technical requirements to produce parts as light as possible with more complex geometries are ever increasing in recent years in automotive industries, rail vehicle and aerospace. Manufacturing technologies such as super-plastic metal forming, which had been considered as a niche technology earlier, is now gaining greater technical relevance for industrial size production. The parts that have been generated through super-plastic forming in innovative vehicle for example Mercedes SLS AMG reflect the industrial activity in this area. Manufacturability of thin-walled structures enables lightweight design. Also the tool and manufacturing costs are lower in comparison. However, the main challenge could be found in maintaining exact process parameters. There is a large research potential in super-plastic forming; from the determination of optimal material data through process simulation to manufacturing of real parts and their characterization. In the framework of the project international Bureau of the Federal Ministry of Education and Research UKR005/08 “Manufacture of parts with special properties” a preliminary research work has been carried out.

• Periodical: Materials Science Forum (Volumes 706-709)
• Pages: 1853-1858
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.706-709.1853
• Online since: January 2012
• Authors: Kyrylo Vorobyov, Valentyn Danchenko, Elmar Beeh, Gundolf Kopp
• Keywords: Severe Plastic Deformation (SPD)

References

[7] On analysing stretch at break it is also clear that test pieces drawn at the higher speed show an additional stretch at break of about 5% after the deformation. The reduction in the stretch at break can be explained by the flow behaviour of the material. Even once additional flow planes become active in the selected alloys, a maximum stretching of up to 60% was achieved in the hot tensile test at a temperature of 250 °C. Necking areas appeared on drawing strips by 50%, leading to varying sheet thicknesses in the samples. With the low strain rate (within the super-plastic domain), the samples achieve a substantially higher level of stretching of up to 135%. The material flow was much more regular in the mechanisms described above. When analysing the stretching behaviour of the super-plastically formed sheets, it can be seen that the material exhibits a sufficient stretch at break after super-plastic forming. Material properties needed for later operations involving conventional processes carried out on components remain unaffected. Summary and Outlook In this paper, the deformation properties of lightweight metal alloys (AA5083-SPF, AA5754 and AZ31) using super-plastic sheet forming were presented. Regression equations were shown and mathematical comparison models were derived, representing the dependencies between mechanical properties of the material and variable process parameters. Time and cost advantages can be achieved by using the result of these experiences and improvements in processes in series production. The most important parameters for the development of super-plastic formed components were identified and made available. Bibliography.

[1] H. Friedrich, P. Steinle, G. Kopp, R. Schöll: Next decades' challenges for terrestrial vehicles' materials and manufacturing to reduce CO2 emissions. In: Journal of Materials Science Forum . Thermec 2009 International Conference on Processing & Manufacturing of Advanced Materials, 25. -29. 08. 2009, Berlin.

DOI: 10.4028/www.scientific.net/msf.638-642.3

[2] J. Nickel, J. Koenig: Innovative lightweight construction concept for the railcar body of the Next Generation Train (NGT) and possibilities for lightweight Rating (German), 11. Internationale Schienenfahrzeugtagung, Dresden, 23. – 25. 02. (2011).

[3] H. Friedrich: Development of superplastic aluminum forming in the aerospace (German), Werkstatt und Betrieb, 1990, 123, pp.945-948.

[4] F. Novik, J. Arsov: Process optimization technology of metals planning methods of the experiment (Russian), Mashinostroenie, Moscow, (1980).

[5] O. Kuzmina,V. Grynkevych: Investigation of the influence parameters of hot deformation on uneven structure of the billets by means of numerical simulation (Russian), In: Sistemni tehnologii. 2005. T. 8. p.484.

[6] V. Danchenko, A. Milenin, V. Kuzmenko, V. Grynkevych: Computer simulation of metal forming (Russian), In: Systemni tehnologii, 2005. p.448.

[7] Novikov I. I., Portnoj V. K.: super plasticity of the alloys. VEB, Leipzig (1985).