Fig. 1. Characteristics of Zr52.5Cu17.9Ni14.6Al10Ti5 BMGs prepared by SLM and casting. (a) X-ray diffraction patterns of rod-like specimens (diameter: 3 mm). Only a broad diffraction maximum can be found, suggesting a fully amorphous structure. (b) DSC curves of as-cast and SLM samples show exothermic structural relaxation. The relaxation enthalpies of SLM samples are larger than for the as-cast samples, indicating a structurally less relaxed state. (c) The defect size distribution and μ-CT reconstruction (inset) of a SLM sample. Pores distribute randomly throughout the whole sample.

Fig. 2. SEM image of a glassy Zr52.5Cu17.9Ni14.6Al10Ti5 sample prepared by SLM after etching. Neither at low (a) or slightly higher magnification do features indicative of the SLM process become apparent.

Fig. 3. Nanohardness maps of Zr52.5Cu17.9Ni14.6Al10Ti5 BMGs prepared by SLM and casting. (a) and (b) hardness contour maps of the longitudinal sections of the SLM sample and the as-cast sample, respectively. The maps are based on 170 indents as indicated by the black dots.

Fig. 4. Statistical analysis of the nanoindentation experiments of Zr52.5Cu17.9Ni14.6Al10Ti5 BMGs prepared by SLM and casting. (a) Probability densities and cumulative probabilities for the as-cast and SLM samples extracted from the maps shown in Fig. 2. The probability density data (open circles) shows a normal distribution (solid lines). (b) Weibull plot of the hardness values for the SLM (m = 59 ± 2) and as-cast (m = 78 ± 4) samples. The Weibull modulus, m, is derived from the slope of the linear regression curve of ln[-ln(1-f)] over ln(H), marked by the dashed lines.

Fig. 5. Stress-strain curves analysis of SLM and as-cast BMGs. (a) True stress-strain curves of Zr52.5Cu17.9Ni14.6Al10Ti5 samples prepared by casting and SLM. Three samples of each manufacturing technique were selected to show the reproducibility of the compression test. All SLM samples yield at stresses lower than the as-cast material and exhibit a smaller plastic strain. An enlarged view of the serrated region is shown in the inset. (b) The normalized stress drop magnitude, s, is given as a function of time. The stress drops in the SLM sample are much smaller than the as-cast one. The histograms of the normalized stress drop magnitude for (c) the as-cast sample and (d) the SLM sample. Please note the different ranges for s. The cumulative probability density for the as-cast (R = 0.995) and the SLM (R = 0.994) sample are depicted in (e) and (f), respectively. Eq. (1) (solid line) describes the data well.

Fig. 6. Deformation of Zr52.5Cu17.9Ni14.6Al10Ti5 BMGs prepared by SLM. (a) True stress-strain curve of a rectangular SLM sample corroborates its plastic deformability. The insets depict the fracture angle of about 45° and the corresponding μ-CT reconstruction. (b) SEM image depicts multiple shear bands interacting with each other and with pores. The regions of interest (marked by dashed circles) are shown at higher magnification in (c) and (d). (e) Shear band initiation at a pore for a sample loaded until plastic deformation, as indicated in (a). Please note that the dark patches are stains at the sample surface.