A micromechanics-based damage constitutive model considering microstructure for aluminum alloys. (October 2022)

• Record Type: Journal Article
• Authors: Xing, L.; Gao, P.F.; Zhan, M.; Ren, Z.P.; Fan, X.G.
• Is Part Of: International journal of plasticity. Volume 157(2022)
• Publication Date: 2022-10
• Subjects: Aluminum alloys -- Damage constitutive modeling -- Evolution of multi-type voids -- Microstructure effects; Plasticity -- Periodicals; Plasticité -- Périodiques; Plasticity; Periodicals; 620.11233
• DOI: 10.1016/j.ijplas.2022.103390
• Languages: English
• ISSNs: 0749-6419

Abstract

Highlights: A new micromechanics-based damage constitutive model considering the phases, grains and voids information is proposed for aluminum alloys. Voids are divided into three types with different mechanisms and separately modeled relative to their local micro-strain/stress and microstructures. The micro-strain/stress of the phases is determined via a self-consistent method considering the voids softening and microstructure effects on the constitutive behavior of each phase. The predicted evolution of each type of void, flow stress and fracture behavior are validated by XCT measurements and tension testing of specimens with various microstructures. The mutual effects between microstructure, voids and deformation behavior of aluminum alloys are captured and revealed. Abstract: Aluminum alloys undergoing deformation exhibit complex multi-type-void damage evolution driven by microscale heterogeneous deformation; in return, the accumulated damage evolution would affect the microscale heterogeneous deformation. Meanwhile, the above interaction depends significantly on the microstructure characteristics and determines the macroscale flow and ductile fracture behaviors. These make it difficult to model the deformation response and ductile fracture of aluminum alloys with various microstructures. Aiming at this issue, a micromechanics-based damage constitutive model considering the mutual effects between microstructure, micro/macro-scale deformation, and damage and fracture was developed in this study for deformation of aluminum alloys under tension-dominated loading conditions. During the modeling, the damage was characterized in terms of the evolutions of coexisting multi-type voids. The multiple-type voids were modeled separately as functions of the local micro-strain/stress of their respective phases and microstructure characteristics according to the micromechanical mechanisms. Furthermore, a self-consistent method was employed to calculate the heterogeneous micro-strain/stress of phases and the overall macroscale flow behavior of the multiphase aggregate. In particular, the constitutive behavior of each phase in the self-consistent method was modeled by coupling the softening effect of void evolution and microstructure characteristics, thus the interaction between microscale heterogeneous deformation and damage evolution was captured. The model parameters were determined by matching the calculated and experimental evolutions of the multi-type voids measured via in-situ synchrotron radiation X-ray computed tomography and load-displacement curves during deformation. Applied to the 2219 aluminum alloy, this model accurately predicts the flow stress, damage evolution and fracture behavior under various microstructures and those of tailor-welded blanks with a gradient microstructure. Furthermore, the model clarifies the mutual effects between the microstructure, damage evolution and deformation behavior of aluminum alloys. The developed model can also be generalized to other multiphase metals containing a distribution of hard-brittle particles. And it is thus believed to be with a well general prediction for the deformation response and ductile fracture of this kind of multiphase metals with various microstructures or gradient microstructures, and further facilitates the understanding of their complex damage evolution and flow behavior. Graphical abstract: Image, graphical abstract