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Title: The strain path dependence of plastic deformation response of AA5754: Experiment and modeling

Journal Article · · AIP Conference Proceedings
DOI:https://doi.org/10.1063/1.4850021· OSTI ID:22261659
 [1];  [2]; ;  [3];  [4]
  1. Materials Science and Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213, USA and NIST Center for Automotive Lightweighting, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899-8553 (United States)
  2. Materials Science and Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213, USA and Now at IBM (United States)
  3. NIST Center for Automotive Lightweighting, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, MD 20899-8553 (United States)
  4. Materials Science and Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213 (United States)

This work presents modeling of experiments on a balanced biaxial (BB) pre-strained AA5754 alloy, subsequently reloaded uniaxially along the rolling direction and transverse direction. The material exhibits a complex plastic deformation response during the change in strain path due to 1) crystallographic texture, 2) aging (interactions between dislocations and Mg atoms) and 3) recovery (annihilation and re-arrangement of dislocations). With a BB prestrain of about 5 %, the aging process is dominant, and the yield strength for uniaxially deformed samples is observed to be higher than the flow stress during BB straining. The strain hardening rate after changing path is, however, lower than that for pre-straining. Higher degrees of pre-straining make the dynamic recovery more active. The dynamic recovery at higher strain levels compensates for the aging effect, and results in: 1) a reduction of the yield strength, and 2) an increase in the hardening rate of re-strained specimens along other directions. The yield strength of deformed samples is further reduced if these samples are left at room temperature to let static recovery occur. The synergistic influences of texture condition, aging and recovery processes on the material response make the modeling of strain path dependence of mechanical behavior of AA5754 challenging. In this study, the influence of crystallographic texture is taken into account by incorporating the latent hardening into a visco-plastic self-consistent model. Different strengths of dislocation glide interaction models in 24 slip systems are used to represent the latent hardening. Moreover, the aging and recovery effects are also included into the latent hardening model by considering strong interactions between dislocations and dissolved atom Mg and the microstructural evolution. These microstructural considerations provide a powerful capability to successfully describe the strain path dependence of plastic deformation behavior of AA5754.

OSTI ID:
22261659
Journal Information:
AIP Conference Proceedings, Vol. 1567, Issue 1; Conference: NUMISHEET 2014: 9. international conference and workshop on numerical simulation of 3D sheet metal forming processes, Melbourne (Australia), 6-10 Jan 2014; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
Country of Publication:
United States
Language:
English