Fig. 1. (a) Particle size distribution of the Cu46Zr46Al8 powder after sieving. The diameters of the powder particles are almost equally distributed between 10 μm and 80 μm in diameter. (b) Scanning electron micrograph of the sieved gas-atomized powder. The powder is spherical with a minor amount of satellites.

Fig. 2. SEM images of the embedded and polished Cu46Zr46Al8 powder particles (a) at low and (b) at higher magnification. The cross sections of the particles are almost all circular and no pores can be detected within the particles.

Fig. 3. Relative density of the additively manufactured Cu46Zr46Al8 samples as a function of the scanning velocity and the laser power at a constant layer thickness (l = 40 μm) and a constant hatch distance ( h = 180 μm). The dashed lines indicate values of constant volume energy input, EV. The values of density were obtained via the Archimedean method.

Fig. 4. μ-CT images of cross sections, the corresponding pore size distributions and the full sample reconstructions (inset) for Cu46Zr46Al8 samples prepared by SLM with different parameters: (a) P = 99 W, v =1000 mm s-1, h = 180 μm and l = 40 μm ( EV = 14.3 J mm-3), (b) P = 120 W, v =1000 mm s-1, h = 180 μm and l = 40 μm ( EV = 17.4 J mm-3), (c) remelted sample (P1 = 99 W, P2 = 120 W, v =1000 mm s-1, h = 180 μm and l = 40 μm). The largest pores found in the samples are smaller after remelting compared to the sample having the highest relative density (i.e. the sample produced with EV = 14.3 J mm-3) while the maximum frequency of the pore size distribution tends to shift to larger pore sizes.

Fig. 5. X-ray diffraction patterns of the Cu46Zr46Al8 powder, the as-cast rods and rods produced by SLM with different energy inputs. Next to the B2 CuZr phase, the big cube phase can be identified.

Fig. 6. (a) The bright-field TEM micrograph of the SLM sample produced at an energy input of EV = 17.4 J mm-3 shows spherical entities with typical sizes around 30-100 nm, which are identified as B2 CuZr crystals (Pm $\bar{3}$ m) according to the selected area electron diffraction (SAED) pattern (inset). (b) The high-resolution TEM image of the B2 CuZr nanocrystals confirms long-range ordering. (c) The TEM micrograph of the remelted SLM sample depicts almost square crystals identified as the big cube phase (Fd $\bar{3}$ m) by means of the corresponding SAED pattern (inset). (d) At a higher magnification, it can be seen that the big cube phase precipitates around B2 CuZr crystals, which most likely serve as heterogeneous nuclei.

Fig. 7. (a) DSC traces of the gas-atomized Cu46Zr46Al8 powder, an as-cast rod and selected SLM samples produced with different energy inputs. (b) Enlarged section of the DSC traces shown in (a). All samples exhibit an endothermic peak related to the glass transition, followed by a single-step exothermic crystallization event. The glass-transition temperature (Tg) and the crystallization temperature (Tx) are marked by arrows. (c) Enlarged DSC traces of the as-cast sample and the SLM samples fabricated at the indicated energy inputs highlighting the temperature region in which (exothermic) structural relaxation occurs.

Fig. 8. Compressive true stress-strain curves of the as-cast and SLM samples produced with different parameters: EV = 14.3 J mm-3 (P = 99 W, v =1000 mm s-1, h = 180 μm, l = 40 μm), EV = 17.4 J mm-3 (P = 120 W, v =1000 mm s-1, h = 180 μm, l =40 μm) and remelted ( P1 = 99 W, P2 = 120 W, v =1000 mm s-1, h = 180 μm, l = 40 μm).

Fig. 9. Fracture surfaces of the SLM samples fabricated with an energy input of EV = 14.3 J mm-3 (a-c) and an as-cast sample (d). The rugged surface implies a more complicated stress state for the SLM sample. Images (b) and (c) were taken from the regions indicated in image (a). The crack and unmelted powder are indicated in (a) and (b).

Fig. 10. (a) Schematic illustration visualizes the locations on the cross and longitudinal sections of as-cast and SLM samples (EV = 14.3 J mm-3) at which microhardness measurements were conducted. (b) and (d) display the microhardness contour maps for the cross sections of the as-cast and SLM-samples, respectively. (c) and (e) depict the microhardness contour maps of the corresponding longitudinal section for as-cast and SLM specimens, respectively.

Fig. 11. Hardness (H) contour maps for the longitudinal section of the SLM samples synthesized with energy inputs of (a) EV = 14.3 J mm-3 (P = 99 W, v =1000 mm s-1, h = 180 μm, l = 40 μm), (b) 17.4 J mm -3 (P = 120 W, v =1000 mm s-1, h = 180 μm, l = 40 μm), (c) remelted ( P1 = 99 W, P2 = 120 W, v =1000 mm s-1, h = 180 μm, l = 40 μm).

Fig. 12. Weibull plot of hardness values for the SLM samples. The Weibull modulus (m) is derived from the slope of the linear regression curve of ln[-ln(1-f)] over ln(H) and indicated by the dashed line.