A new crystal plasticity framework to simulate the large strain behaviour of aluminum alloys at warm temperatures

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:727

Article

Cyr, Edward D.¹  Brahme, Abhijit¹  Mohammadi, Mohsen²  Mishra, Raja K.³  Inal, Kaan¹ 

[1] Univ Waterloo, Dept Mech & Mechatron Engn, Waterloo, ON N2L 3G1, Canada

[2] Univ New Brunswick, Dept Mech Engn, Fredericton, NB, Canada

[3] Gen Motors Res & Dev Ctr, Warren, MI 48090 USA

关键词: Crystal plasticity;    Dislocation;    Recovery;    Temperature;    Aluminum;    Texture;   

DOI  :  10.1016/j.msea.2018.04.020

来源: Elsevier

【 摘 要 】

To improve metal formability, high temperature forming has become a desired manufacturing process. Phenomenological plasticity models are widely used in this application, however lack good predictive capability concerning microstructure evolution during forming. Many crystal plasticity hardening models have been developed to predict deformation phenomena of metals during high temperature forming; however, few have thermodynamic self-hardening formulations based on deformation mechanisms. This work presents a crystal plasticity based analysis with a Taylor polycrystal averaging scheme of warm forming employing a new microstructure and dislocation based strain hardening model to simulate deformation behaviour. The hardening model is derived from energy balance between dislocation storage, dislocation accumulation, and dislocation recovery, based on remobilization of immobile dislocations, due to thermal activation. The constitutive formulation is extended to include alloying effects due to solute strengthening of Mg. The material hardening properties of AA5754 are characterized for a range of temperatures at constant strain-rates. A formulation for the kinematics of dynamic strain aging is presented and employed for room-temperature simulations. The hardening characterization is then used to predict stress-strain behaviour of AA5182 for similar conditions. The model shows excellent predictability of experimental results. An analysis on the microstructural connection between temperature and stress-strain response is presented.

【 授权许可】

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