Description
During forming processing of AA6082 aluminium alloy, dynamic recovery can occur even at room temperature. Especially at high strain rates and heterogeneous deformation conditions, deformation bands and adiabatic shear bands can be formed. This work proposes a physical-based model to describe the evolution of dislocation densities, boundary misorientation distribution, fractions of high and low-angle grain boundaries, and grain and subgrain sizes during the plastic deformation of hat-shaped samples. Three populations of dislocation densities are considered: mobile, immobile and wall dislocation densities. Furthermore, the microstructural evolution is coupled with constitutive equations to predict the flow stress of the material based on the strain, strain rate, and deformation temperature. The complex hat-shaped geometry leads to large temperature and effective strain rate gradients, promoting a heterogeneous deformation within the workpiece. The AA6082 samples are deformed under compression at different temperatures ranging from 350°C to 500°C and strain rates between 0.01s-1 and 10s-1 using the Gleeble®3800 thermomechanical simulator. The microstructure characterization is conducted via scanning electron microscopy assisted by electron backscattered diffraction. The experimental flow curves obtained from compression tests of cylindrical samples and the information gathered from the microstructural characterization of non-deformed and deformed samples are used to adjust and validate the model. Ultimately, the model is implemented in DEFORM, a Finite Element Method (FEM) simulation software, to predict the microstructure evolution of the hat-shaped samples during deformation. Highly deformed regions show a refined microstructure due to the formation of low-angle grain boundaries, which develop into high-angle grain boundaries by progressive crystal rotation.| Period | 21 Jun 2023 → 23 Jun 2023 |
|---|---|
| Event title | 5th International Conference on Light Materials: LightMAT 2023 |
| Event type | Conference |
| Location | Trondheim, NorwayShow on map |
| Degree of Recognition | International |
Keywords
- AA6082
- microstructural modelling
- hat-shaped samples
- dislocation density
- deformation bands
ASJC Scopus subject areas
- Materials Science(all)
Fields of Expertise
- Advanced Materials Science