Fig. 2: Grain refinement of the AM-fabricated Ti-6Al-4V by high-intensity ultrasound.
From: Grain structure control during metal 3D printing by high-intensity ultrasound
a, b Optical microscopy images of the samples without (a) and with (b) ultrasound. c, d Polarized light microscopy images showing large columnar grains (c) and fine equiaxed grains (d). e, f Histograms of the prior-β grain size (e) and prior-β grain aspect ratio (f) for the samples without and with ultrasound measured from traced prior-β grain images (see Supplementary Fig. 1). The prior-β grain boundaries in c and d are traced in white. Scale bars, 1 mm.
