Fig. 1
From: Hierarchical nanostructured aluminum alloy with ultrahigh strength and large plasticity
Hierarchical nanostructure guided from computer simulation. a The atomistic model of the glass-crystal hierarchical nanostructure composed of amorphous Al85Ni15 and Al nanograins. b MD simulated atomic snapshot and c the corresponding atomic shear strain distribution of the hierarchical nanostructured Al alloy at a strain of 30%. ‘G1’ and ‘G2’ in b represent a flattened ‘grain 1’ and a rotated ‘grain 2’, respectively. The typical dislocation slips in ‘G1’ contribute to plastic deformation. Large rotation with little dislocation propagation in ‘G2’ may also accommodate the plastic deformation. d Optical image of the hierarchical nanostructured Al alloy. e Cross-sectional TEM image of the hierarchical nanostructured Al alloy, showing Al nanograins surrounded with light–dark contrasted grain–grain interfaces. The selected area electron diffraction (SAED) pattern in the inset denotes the polycrystalline structure. f HRTEM image of the hierarchical nanostructured Al alloy, showing a crystalline Al nanograin is surrounded by amorphous phase (post-colored by light yellow). The inset is fast Fourier transformation (FFT) image of the white dashed rectangle region in the main image, showing the fcc structure with zone axis of [0 1 1]. g, h are the zoomed-in images of white and black dashed rectangle regions in (f), respectively. g Shows a defect-free fcc structure. h Shows a nano-sized amorphous phase forms between the two grains. The FFT image (lower right inset of h) of the crystalline region (white dashed rectangle) reveals pronounced spots pattern. By contrast, the FFT image (upper left inset of h) of the black dashed rectangle region in h shows a diffuse pattern, indicating the amorphous structure. The termination ripples feature may be due to the small sampling size
