Page 101 - Read Online

Page 26 of 45 Mooraj et al. J Mater Inf 2023;3:4 https://dx.doi.org/10.20517/jmi.2022.41

Figure 12. (A) Radar chart comparing properties of various promising compositions discovered from graded material library of the
[172]
Co-Fe-Ni system. This figure is quoted with permission from Teh et al. , copyright 2022, Elsevier; (B) change in V concentration
along the build direction for AlMoV CrFe alloy. This figure is quoted with permission from Gwalani et al. [173] , copyright 2019,
x
Elsevier; (C) vickers hardness map of the side surface of graded CoCrFeNiTi HEA system. This figure is quoted with permission from
x
Zhao et al. [174] , copyright 2021, Elsevier. HEA: High-entropy alloy.
Bulk materials library
While graded materials provide a convenient means to explore multiple compositions within a single
sample, they cannot give a full picture of material performance due to the possible mixing between layers
during LAM, which can be difficult to control. In this sense, bulk materials libraries can produce individual
samples to be studied in further detail while maintaining a high-throughput approach if rapid
characterization techniques can be applied. One such example is illustrated in Figure 13A, where Yu et al.
used DED to produce a library of bulk samples using elemental Al powder and Cu Zr powder in separate
[175] 50 50
powder hoppers, as seen in Figure 13A . This work aimed to find the optimal compositions and
processing conditions to produce bulk metallic glass composites (BMGC). BMGCs are materials formed by
[176]
adding a crystalline phase into a glassy amorphous matrix .

The crystalline phase helps hinder the propagation of shear bands and dissipate fracture energy, which can
significantly improve the room temperature ductility of BMGCs compared to monolithic bulk metallic
[155]
glasses . In their work, BMGC samples were deposited and then remelted to produce initially deposited
melt pools with similar dimensions and different cooling rates. An 11 × 11 sample library was produced
where the Al content was adjusted from 0 at. % to 10 at. % along the x-direction while the laser power was
varied along the y-direction from 150 W to 400 W. Finite element modeling (FEM) was used to estimate the
cooling rates and XRD analysis was used to confirm the phase constitution. After identifying phases with
both amorphous and crystalline phases, the authors defined a uniformity coefficient to estimate the sample
that would be expected to show the highest ductility. This criterion arose because ductility is closely related