Page 447 - IJB-10-4

International Journal of Bioprinting Improving ductility of 3D-printed Zn–Mg

Figure 11. Electron backscatter diffraction (EBSD) analysis of the laser powder bed fusion (LPBF)-fabricated Zn–Mg alloy with and without annealing
(300℃ for 0.5 h): (a–c) bond contrast map, grain size map, and recrystallized microstructure map of the as-built alloy, respectively; (d–f) bond contrast
map, grain size map, and recrystallized microstructure map of the annealed alloy, respectively; (g and h) the grain size distribution of the as-built and
annealed alloy, respectively; and (i and j) pole figure of the as-built and annealed alloy, respectively.

the holding time was 1 h, tensile strength and elongation the annealed Zn–Mg alloy exhibited higher tensile strength
were 175.88 ± 3.24 MPa and 6.53 ± 0.10%, respectively. than most LPBF-fabricated counterparts. These findings
At 365°C, there was no significant difference observed in indicated that annealing can effectively improve the overall
the tensile strength and elongation of the alloy after 0.5, mechanical properties of as-built Zn–Mg alloys.
1, and 2 h of holding; they remained consistently lower at
approximately 90 MPa and 0.8%. When the temperature The tensile fractured morphology of the annealed
exceeded the optimal range, the influence of holding time Zn–1Mg alloy was characterized using SEM to further
on mechanical properties was relatively minimal, resulting investigate the influence of annealing (Figure 13). In Figure
in a sustained lower level. Furthermore, it was found that 13a, the fractured surface of the Zn–Mg alloy annealed
all annealing conditions generally resulted in reduced at 250℃ exhibited distinct features, such as cleavage
tensile strength of the annealed alloy compared to the as- steps and river-like patterns, accompanied by numerous
built alloy. The comparative analysis of tensile performance smooth cleavage planes of 20–40 μm in length, indicating
for LPBF-fabricated Zn–Mg is presented in Figure 12c. pronounced brittleness and a quasi-cleavage fracture
Notably, the elongation of the Zn–Mg alloy after annealing mode. In Figure 13b, the fractured surface of the Zn–Mg
exceeded those of the LPBF-fabricated Zn–Mg alloy, and alloy annealed at 300℃ displayed smaller dimensions for

Volume 10 Issue 4 (2024) 439 doi: 10.36922/ijb.3034