*3.3. Mechanical Performance*

Figure 9a depicts the nanoindentation load–displacement curves measured on the polished sections of the as-built struts with an angle of 90◦ and *L*s values of 0.4 and 1.4 mm. The indentation depths of the struts with an *L*s value of 1.4 mm were larger than those of the struts with an *L*s value of 0.4 mm after unloading. As shown in Figure 9b,c, for the struts with a *v* of 1300 mm/s, the nanohardness and elastic modulus increased with increasing geometric characteristic size. It is noteworthy that the nanohardness and elastic modulus increased very slightly and indistinctively after *L*s reached 1 mm. For the struts with an *L*s value of 0.4 mm, the nanohardness reached 3.78 to 4.12 GPa and the elastic modulus reached 96.044 to 110.613 GPa. For the struts with an *L*s value of 1.4 mm, the nanohardness reached 4.12 to 4.4 GPa and the elastic modulus reached 126.42 to 131.57 GPa. Overall, they all decreased with increasing scan speed.

**Figure 9.** (**a**) Loading–unloading curves; (**b**,**<sup>c</sup>**) the calculated elastic modulus and nanohardness from the nanoindentation tests.
