Fine-grained AA5083 aluminum sheet is used for hot-forming automotive body panels with gas pressure in the superplastic forming (SPF) and quick plastic forming (QPF) processes. Deformation under QPF conditions is controlled by two fundamental creep mechanisms, grain-boundary-sliding (GBS) and solute-drag (SD) creep. The failure mechanisms of AA5083 materials under QPF conditions depend strongly on these deformation mechanisms and on the applied stress state. Failure can be controlled by flow localization, cavitation development or a combination of both. There is interest in using continuously cast (CC) AA5083 materials instead of direct-chill cast (DC) materials in QPF operations as a means of reducing material cost. However, CC and DC AA5083 materials can produce significantly different ductilities under hot forming. Rupture-based forming-limit diagrams (FLDs) have been constructed for a CC AA5083 sheet material under hot-forming conditions. Forming limits are shown to be related to the controlling deformation mechanisms. Differences between FLDs from DC and CC AA5083 materials are investigated. The differences in FLDs between these materials are related to differences in cavitation development.
Similar content being viewed by others
References
J.G. Schroth, (2004) General Motors Quick Plastic Forming Process. In: E.M. Taleff, P.A. Friedman, P.E. Krajewski, R.S. Mishra, J.G. Schroth (Eds.) Advances in Superplasticity and Superplastic Forming. TMS: Warrendale, PA, pp. 9–20
M.-A. Kulas, W.P. Green, E.M. Taleff, P.E. Krajewski, T.R. McNelley (2005) Deformation Mechanisms in Superplastic AA5083 Materials. Metall. Mater. Trans. A 36A:1249–1261
E.M. Taleff, (2004) An Overview of Creep Deformation Behaviors in 5000-Series and Al-Mg Alloys. In: E.M. Taleff, P.A. Friedman, P.E. Krajewski, R.S. Mishra, J.G. Schroth (Eds.) Advances in Superplasticity and Superplastic Forming. TMS: Warrendale, PA, pp. 85–94
M.-A. Kulas, W.P. Green, E.M. Taleff, P.E. Krajewski, T.R. McNelley, (2006) Failure Mechanisms in Superplastic AA5083 Materials. Met. Metall. Mater. Trans. A 37A:645–655
M.-A. Kulas, P.E. Krajewski, J.R. Bradley, E.M. Taleff, (2007) Forming Limit Diagrams for AA5083 under SPF and QPF Conditions. Materials Science Forum, 551–552:129–134
S.P. Keeler, W.A. Backofen, (1963) Plastic Instability and Fracture in Sheets Stretched over Rigid Punches. Trans. ASM. 56:25–47
S.P. Keeler, Rating the Formability of Sheet Metal. Metal Progress, 1966, 90, p 148–153
G.M. Goodwin, “Application of Strain Analysis to Sheet Metal Forming Problems in the Press Shop,” SAE Transactions: SAE Paper No. 680093 (1968), p 380–387
J.R. Bradley, (2004) Bulge Testing of Superplastic AA5083 Aluminum Sheet. In: E.M. Taleff, P.A. Friedman, P.E. Krajewski, R.S. Mishra, J.G. Schroth (Eds) Advances in Superplasticity and Superplastic Forming. TMS: Warrendale, PA, pp. 109–118
D.H. Bae, A.K. Ghosh, J.R. Bradley, (2003) Stress-State Dependence of Cavitation and Flow Behavior in Superplastic Aluminum Alloys. Metall. Mater. Trans. A 34A:2449–2463
Author information
Authors and Affiliations
Corresponding author
Additional information
This article was presented at Materials Science & Technology 2006, Innovations in Metal Forming symposium held October 15-19, 2006 Cincinnati, OH.
Rights and permissions
About this article
Cite this article
Kulas, MA., Krajewski, P.E., Bradley, J.R. et al. Forming-Limit Diagrams for Hot-Forming of AA5083 Aluminum Sheet: Continuously Cast Material. J. of Materi Eng and Perform 16, 308–313 (2007). https://doi.org/10.1007/s11665-007-9057-8
Received:
Revised:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11665-007-9057-8