Page 27 - MSAM-1-2

Materials Science in Additive Manufacturing Laser absorption and printability of 90W-Ni-Fe

A B

C D

E E

Figure 11. SEM images showing top surface morphologies (A, C, and E) and 3D morphologies describing the side surface (B, D, and F) of LPBF-processed
90W-Ni-Fe alloys fabricated by different powder: severely agglomeration (A and B), uniformly dispersion (C and D), and deformation (E and F).
energy conversion factor of the homogeneous powder with morphologies on the densification level of LPBF-processed
good sphericity was high and stable, lowering the dynamic 90W-Ni-Fe parts, OM images of specimens fabricated
viscosity of the molten pool, and yielding a sufficient liquid by different powders were observed (Figure 12). The
lifetime for wetting and spreading behavior [14,24] . Hence, densification level of the specimens increased and then
the spattering and balling effects were reduced, improving decreased as the milling energy increased. Homogeneous
the surface quality of LPBF-fabricated 90W-Ni-Fe parts. In powder with high sphericity had the highest densification
this instance, the surface roughness (S ) of the fabricated level (density of 98%). This was attributed to the fact that
a
specimen was 7.91 μm. When the enhanced particles were homogeneous nanoparticle-coated 90W-Ni-Fe powder
agglomerated or the matrix particles were deformed, the with high sphericity had the best laser absorption behavior,
surface roughness (S ) of the fabricated specimen was 20.05 thus improving the wetting and spreading behavior of
a
μm and 29.41 μm, respectively. This can be attributed to LPBF [29,30] . The trends of results obtained from the single
the unstable laser absorption behavior which reduced the tracks and bulk fabrications were correlated. With the high
stability of the molten pool, leading to the splashing and quality of the scanning track, the metallurgical bonding
balling effects, reducing the surface quality of the LPBF- of processed specimens improved, thereby increasing the
processed specimens [14,24-26] . density of the fabricated W-Ni-Fe specimen.
The stability of the molten pool also tends to affect The above results show that the powder morphology
the densification behavior of LPBF-fabricated 90W-Ni-Fe does influence the LPBF printing quality of 90W-Ni-Fe
alloys, which has an important influence on its mechanical alloys and homogeneous powder with high sphericity
properties [4,13,34] . To investigate the effects of powder has the sound laser absorption behavior; these help

Volume 1 Issue 2 (2022) 9 http://doi.org/10.18063/msam.v1i2.11