Speaker
Description
Solid-state processing techniques like friction extrusion (FE), friction stir welding (FSW), and friction surfacing (FS), represent advanced methods for processing Al alloys. These techniques utilize frictional heat and intense mechanical deformation to induce microstructural evolution without reaching the melting point. This study focuses on Al-Cu-Li alloys, which are widely employed in the aerospace industry due to their exceptional strength-to-weight ratio and superior mechanical properties. The extreme stress and strain conditions inherent to these processes pose challenges for directly observing microstructural transformations, necessitating the use of numerical modelling to simulate microstructural evolution and optimize processing parameters.
Different dynamic recrystallization mechanisms (DRX) occur during FE, FS and FSW, depending on the stacking fault energy of the processed alloy but also on the specific processing conditions. To investigate these phenomena, this study presents a fully coupled computational framework that integrates the multiphase-field (MPF) method with a crystal plasticity (CP) model. The MPF method is used to simulate nucleation and grain boundary migration, while the CP model captures anisotropic mechanical behavior, including strain hardening, lattice rotation, and texture evolution. The framework employs a Fast Fourier Transform (FFT) based finite-strain elasticity solver to enhance computational efficiency. This integrated framework establishes a direct linkage between microstructural evolution and macroscopic mechanical responses, enabling a detailed understanding of the interplay between processing conditions, microstructural changes, and material performance in polycrystalline Al alloys during solid-state processing.
