Speaker
Description
The formability of Al2050 alloy is critical for manufacturing large and thick components while maintaining its outstanding performance [1]. Previous studies showed that pores and cracks occur during the hot deformation of this alloy and the pore growth follows three different paths (exponential, decelerated, mixed) [2]. To link the damage development during high-temperature loading with the alloy microstructure evolution, an in-situ tensile loading at 480 ºC was performed on this alloy using synchrotron diffraction and tomography, i.e. diffraction contrast tomography (DCT) to provide 3D grain maps at ~1.1 µm resolution and phase contrast tomography (PCT) to characterize pores and intermetallic phases with 0.55 µm voxel size and scanning 3DXRD (s3DXRD) to obtain 2D grain and elastic strain maps at 0.5 µm resolution. The pore density and volume fraction were quantified as a function of macroscopic strain up to 20% and three pore formation mechanisms were identified: growth from pre-existing pores, fracture of the intermetallic particles, and nucleation of new pores. The characteristics of the pore evolution are then linked with the grain structure (grain boundaries, orientations and strains) characterized by DCT and s3DXRD. Additionally, the grain maps show newly recrystallized grains, suggesting the presence of dynamic recrystallization. To exclude the possible explanation by annealing recrystallization, an in-situ annealing experiment at 480 ºC without external loading was performed and the results confirmed no recrystallized grains. This study demonstrates that correlating synchrotron grain mapping techniques with tomography offers comprehensive insight in linking the damage development with the microstructure evolution under high-temperature deformation.
References
[1] M.J. Couper, A.E. Neeson and J.R. Griffiths, Fatigue Fract. Engng Mater. Struct. 13, 213-227 (1990).
[2] A.A. Harrup Gutierrez, PhD Thesis (2024).
