Fig. 6: Deformation behaviour of the LPBF AlLaScZr alloy at 300 °C.
a Scanning transmission electron microscopy–bright-field (STEM-BF) image showing the dislocations within α-Al cells of the AlLaScZr-ECN sample under tensile strain of 2%. The red arrows indicate the single dislocation segments between the cell walls and the blue arrows indicate the intracellular dislocation interactions with precipitates; b STEM-BF image showing the dislocations in α-Al cells at the fracture strain; c Micro-cracks owing to broken ECN near the fracture surface; d STEM-BF image showing dislocations in the AlLaScZr-NP sample subjected to tensile strain of 2%. The red arrows indicate longer dislocation segments in the continuous Al matrix; e STEM-BF image showing the dislocation behaviour in the annealed sample deformed at 300 °C at the fracture strain; f Micro-cracks in continuous Al matrix near the fracture surface; g Plot of the critical stress for Orowan bowing at 300 °C during confined layer slip (CLS) (calculated by Eq. (1)) and Frank–Read (F–R) source activation (calculated by Eq. (2)) as a function of the layer thickness/dislocation segment length, with a schematic of dislocation behaviour in the presence of ECN or dispersed particles. The solid lines indicate dominant CLS or F–R mechanisms, while the dotted lines show inactivation within a specific range of dislocation segment length. The cell size distribution histogram of the AlLaScZr-ECN (extracted from Fig. 2d) is also referenced; h HRTEM image depicting a local highly strained region near a dislocation line within Al matrix between neighbouring cell walls. i Inverse fast Fourier transform (IFFT) pattern and geometrical phase analysis (GPA) mappings of (h).
