TY - JOUR
T1 - A holistic approach for evaluation of Gaussian versus ring beam processing on structure and properties in laser powder bed fusion
AU - Singh, Jaivindra
AU - Oliveira, J. P.
AU - Taylor, Hunter
AU - Mireles, Jorge
AU - Wicker, Ryan
N1 - info:eu-repo/grantAgreement/FCT/6817 - DCRRNI ID/UIDP%2F50025%2F2020/PT#
UIDP/50025/2020#
Funding Information:
The research described here was performed at The University of Texas at El Paso (UTEP) within the W.M. Keck Center for 3D Innovation (Keck Center). The authors are grateful to UTEP students Alejandra Hernandez for completing the laser beam analysis, Julissa Arteaga and Kevin Renteria for completing microstructure analysis of all artifacts, Ernesto Gamboa for completing tensile testing, and Angel Bravo for completing hardness measurements. This material is based on research sponsored by, in part, the Air Force Research Laboratory (AFRL) under agreement number FA8650-20-2-5700 and award 70NANB21H006 from the U.S. Department of Commerce, National Institute of Standards and Technology (NIST) . Additional support was provided by strategic investments via discretionary UTEP Keck Center funds and the Mr. and Mrs. MacIntosh Murchison Chair I in Engineering Endowment at UTEP. Jaivindra Singh and J. P. Oliveira acknowledge funding by national funds from FCT - Fundação para a Ciência e a Tecnologia , I.P., in the scope of the projects LA/P/0037/2020 , . The U.S. Government is authorized to reproduce and distribute reprints for Governmental purposes notwithstanding any copyright notation thereon. The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of AFRL or the U.S. Government.
Publisher Copyright:
© 2024
PY - 2024/4
Y1 - 2024/4
N2 - In this study, a holistic evaluation strategy employing a complex test artifact, coupled with single line scan tracks, was employed to examine the influence of different laser beam energy profiles on various features of laser-based powder bed fusion of metals (PBF-LB/M). Using IN718, results revealed a significant influence of the laser beam on bead geometry. Specifically, the conventional Gaussian beam produced deeper, concave-shaped melt pools, while the ring beam resulted in wider and shallower beads. In terms of productivity, the artifacts (two each) fabricated using the Gaussian beam required 6 h and 6 min of build time, while those built using ring beam required only 3 h and 49 min (37% build time reduction) but a defocused Gaussian beam (not included in this study) can match the productivity of the ring beam. However, the holistic approach using the complex test artifact highlighted drawbacks associated with the ring beam, including increased lack of fusion porosity, compromised resolution for features below 0.5 mm, and less than 10% elongation to break in both as built and heat-treated conditions. While acknowledging the potential for improvement through further process optimization, the study concludes that the shallower melt pools produced by the ring beam may cause limitations as layer thicknesses increase. Microstructural analysis revealed distinct grain characteristics, with the Gaussian beam producing more equiaxed grains and the ring beam favouring columnar grains positioned along the build direction. The work primarily highlights the need for and benefits from a holistic analysis in PBF-LB/M technology, ensuring data driven outcomes.
AB - In this study, a holistic evaluation strategy employing a complex test artifact, coupled with single line scan tracks, was employed to examine the influence of different laser beam energy profiles on various features of laser-based powder bed fusion of metals (PBF-LB/M). Using IN718, results revealed a significant influence of the laser beam on bead geometry. Specifically, the conventional Gaussian beam produced deeper, concave-shaped melt pools, while the ring beam resulted in wider and shallower beads. In terms of productivity, the artifacts (two each) fabricated using the Gaussian beam required 6 h and 6 min of build time, while those built using ring beam required only 3 h and 49 min (37% build time reduction) but a defocused Gaussian beam (not included in this study) can match the productivity of the ring beam. However, the holistic approach using the complex test artifact highlighted drawbacks associated with the ring beam, including increased lack of fusion porosity, compromised resolution for features below 0.5 mm, and less than 10% elongation to break in both as built and heat-treated conditions. While acknowledging the potential for improvement through further process optimization, the study concludes that the shallower melt pools produced by the ring beam may cause limitations as layer thicknesses increase. Microstructural analysis revealed distinct grain characteristics, with the Gaussian beam producing more equiaxed grains and the ring beam favouring columnar grains positioned along the build direction. The work primarily highlights the need for and benefits from a holistic analysis in PBF-LB/M technology, ensuring data driven outcomes.
KW - Beam Shaping
KW - Laser powder bed fusion
KW - Mechanical properties
KW - Microstructure
KW - Single line scan
KW - Test artifact
UR - http://www.scopus.com/inward/record.url?scp=85183470868&partnerID=8YFLogxK
U2 - 10.1016/j.jmatprotec.2024.118293
DO - 10.1016/j.jmatprotec.2024.118293
M3 - Article
AN - SCOPUS:85183470868
SN - 0924-0136
VL - 325
JO - Journal Of Materials Processing Technology
JF - Journal Of Materials Processing Technology
M1 - 118293
ER -