A transient carbon nanocoating for improved processing efficiency of copper during laser powder bed fusion
File(s)
Published version
Author(s)
Cheng, Kaka
Karavasilis, Zacharias
Bell, Jamie
Larsen, Sebastian
Hooper, Paul A
Type
Journal Article
Abstract
Laser Powder Bed Fusion (LPBF) of copper faces significant challenges due to copper's high thermal conductivity and low laser absorptivity, leading to melt pool instability, excessive spattering, and poor part quality. To address these issues, this study introduces a novel transient nanocoating strategy that temporarily enhances laser absorption while being designed to vaporise during processing to preserve the purity of the copper. Combined with a defocused laser strategy, this approach achieves a more uniform energy distribution, resulting in a stable melt pool, controlled vapour formation, and minimal spatter. The effectiveness of this synergistic strategy is validated through static and dynamic absorptivity measurements. For the static absorptivity, the coated copper powder absorbs 67% of the input laser power, 3.5 times higher than untreated copper, achieving the highest absorptivity enhancement (147% per 1wt% of additive) reported to date. The dynamic absorptivity is also improved from 12% for untreated copper to 51% for coated copper powder. These advancements not only establish a transformative pathway for the LPBF of copper and other highly reflective metals but also highlight the approach's potential to enhance energy efficiency and promote sustainable manufacturing practices in advanced material processing.
Date Issued
2025-10-01
Date Acceptance
2025-08-08
Citation
Materials and Design, 2025, 258
ISSN
0264-1275
Publisher
Elsevier
Journal / Book Title
Materials and Design
Volume
258
Copyright Statement
© 2025 Published by Elsevier.
Publication Status
Published
Article Number
114552
Date Publish Online
2025-08-13