Poor surface quality represents an important issue that needs improvement for
metal Additively Manufactured parts. Both short or long wavelength lasers have been applied
for surface polishing in order to improve the surface finish. In this work, the possible use of a
CO2 laser for the surface polishing of AlSi10Mg parts made by Laser-based Powder Bed
Fusion (L-PBF) was explored. The high surface roughness in the as-built condition can lead to
increased laser energy absorption. In order to assess the effects of the main laser-related process
parameters, the experiments were carried out on L-PBF samples built vertically with respect to
the build platform. Their effect on the surface were evaluated by means of the surface
arithmetical mean height (Sa), surface skewness (Ssk) and primary profile root mean square
slope (Pdq), obtained via confocal microscopy. Microstructure evolution was also
investigated by means of SEM and EDS analysis. The results showed a large reduction in
surface roughness, ranging from the 67% to the 85% of the starting value. Microstructure of
the remolten layer revealed an increased grain size and an increased Si content that led to an
overall hardness increase from 85 to 121 HV.
Metadata
Item Type:
Article (Published)
Refereed:
Yes
Additional Information:
Article number: 127291
Uncontrolled Keywords:
L-PBF; AlSi10Mg alloy; CO2 laser polishing; Surface roughness; SEM-EDS