3D microstructure-based modelling of ductile damage at large plastic strains in an aluminum sheet

• Published in: International journal of plasticity 2024-10, Vol.181, p.104088, Article 104088
• Main Authors: Sarmah, Abhishek, Asqardoust, Shahryar, Jain, Mukesh K, Yuan, Hui
• Format: Article
• Language: English
• Subjects: 3D EBSD; Cracking; Decohesion; Ductile damage; Tomography
• ISSN: 0749-6419
• DOI: 10.1016/j.ijplas.2024.104088

•Damage evolution in structural AA7075 aluminum alloy is investigated using real microstructure based finite element (FE) models, created from plasma focused ion beam- Scanning Electron microscopy (PFIB-SEM) tomography and 3D electron back scattered diffraction (3D-EBSD) experiments.•Particle decohesion tends to have detrimental effect on the work hardening capacity of the material and induces early necking. Particle cracking does not have appreciable effect on the materials work hardening capability but can trigger early specimen fracture.•Void growth and coalescence is influenced by local stress state, which in turn is influenced by particle decohesion and particle cracking. Post-decohesion, local stress state of the matrix close to particle poles along loading direction becomes conducive for void coalescence. A decohered particle experience contraction close to pole, transverse to the loading direction, which can suppress void coalescence.•Particle cracking can induce conditions favorable for void coalescence through the matrix close to particle poles, both along the loading direction as well as transverse to the loading direction. Irregularly shaped particles can crack multiple times leading to multiples possible sites for void coalescence.•The effect of grains on damage evolution in AA7075 was found to be marginal. Damage initiation in high-strength aluminum alloys with a precipitate-rich matrix is typically particle-driven. In AA7075-O temper, particle cracking and decohesion are the primary void nucleation mechanisms. However, the impact of particle-induced voiding on subsequent void growth and coalescence remains inadequately understood. Given that void growth and coalescence are inherently three-dimensional (3D) phenomena, conventional two-dimensional microstructure-based numerical models fail to accurately capture these damage evolution processes. The current work investigates void growth and coalescence phenomena in AA7075-O by developing 3D finite element (FE) real microstructure based models, created from plasma focused ion beam-scanning electron (PFIB-SEM) tomography and 3D electron back scattered diffraction (3D-EBSD). The models incorporate three key damage processes: particle cracking, particle decohesion, and matrix damage, to examine their effects on void growth and coalescence behavior in AA7075-O. Additionally, the influence of aluminum matrix grains on damage evolution in AA7075-O is explored. Complementary multi-scale modeling tools,