Microstructural characterization and mechanical properties of AlMg alloy fabricated by additive friction stir deposition

This work investigates microstructure characterization and mechanical properties of Aluminum alloy fabricated by additive friction stir deposition (AFSD). Microstructure characterize of the Aluminum alloy 5B70 base material (BM) and build were compared using optical microscope (OM) and electron back scattered diffraction (EBSD). Hardness distribution in the direction perpendicular to the cross-section of deposited area was measured and the pattern was evaluated. Tensile tests were performed on the BM and the deposition using digital image correlation (DIC), and the stress distribution states of the specimens were analyzed in real time. After the tensile tests, the fracture micromorphology was characterized using scanning electron microscope (SEM). The results show that a high degree of recrystallization of the grains in the deposition zone occurs and fine equiaxed grains are formed, which are oriented differently. In tensile tests on the deposition, it was found that the strength of the deposition was significantly lower compared to the BM, but its toughness was significantly higher. And there is a significant anisotropy in the mechanical properties of the deposition.