Authors:
John Power (1), Owen Humphreys (1), Mark Hartnet (2), and Denis Dowling (1)
1-Form Centre, School of Mechanical and Materials Engineering, University College Dublin, Belfield, Ireland
2-Irish Manufacturing Research, Dublin, Ireland
Abstract:
The evolution of laser powder bed fusion (L-PBF) has provided increased design flexibility in the fabrication of a range of parts, including aerospace components and medical devices. The presence of overhangs in metal alloy print structures, however, can give rise to enhanced levels of print defects such as porosity. This is associated with overheating of the alloy meltpool in the region around the overhang structures. This study demonstrated the effectiveness of in-situ meltpool process monitoring as a route to assist laser parameter optimisation for printed Ti-6Al-4V alloy parts. Informed by the observations from the process monitoring of the laser meltpool, the laser parameters are controlled to prevent overheating in the area around the overhang, yielding a more homogeneous printed part’s microstructure. In addition to microstructure optimisation, the enhanced control of the L-PBF process yielded an 88% reduction in overhang roughness (Ra) and a 75% reduction in porosity.
DOI:
https://doi.org/10.59499/EP246277046
