Loading...
Thermal transport and defect evolution in laser powder bed fused copper and copper-silver alloys
Baroutaji, Ahmad
Baroutaji, Ahmad
Editors
Other contributors
Epub Date
Issue Date
2026-07-01
Submitted date
Files
Loading...
Published version
Adobe PDF, 4.32 MB
Alternative
Abstract
Why does adding a highly conductive Ag reduce overall heat transport in LPBF CuAg alloys? This study reveals that the answer lies not in composition alone, but in the combined effects of microstructure and defect evolution during processing. Pure Cu, CuAg10 and CuAg20 were laser powder bed fused under identical conditions (370 W, 400 mm/s, 30 µm layer thickness), with powder analysis confirming relatively uniform particle distributions with D50 of 36.2 µm for Cu, 34.7 µm for CuAg10, and 34.2 µm for CuAg20. Despite this, microstructural observations showed a clear deterioration in densification with increasing Ag content, where relative density decreased from 98% to 99% in Cu to 90–94% in CuAg20, and porosity increased from 1% to 2% to 6–10%. More critically, defect morphology evolved from small, spherical gas pores to large, irregular lack-of-fusion defects approaching 250 µm. These changes translated directly into thermal performance, with as-built conductivity decreasing from 273.25 W/m·K (Cu) to 236.11 W/m·K (CuAg20), despite the intrinsically higher conductivity of silver (Ag). Hot isostatic pressing (900 °C, 1500 bar, 2 h) improved conductivity by 10–15%, reaching 313.31 W/m·K for Cu and 264.10 W/m·K for CuAg20. Although the performance remained well below the rule-of-mixtures limit ~400 W/m·K. A strong correlation (R² = 0.997) between pore size and aspect ratio highlighted the increasing severity of defects, which was quantified using a defect severity parameter. The resulting semi-empirical model predicted conductivity with high accuracy, demonstrating that thermal transport in LPBF CuAg alloys is governed by a coupled effect of process-induced defects and intrinsic alloy scattering rather than porosity alone.
Citation
Wanniarachchi, C.T., Robinson, J., Arjunan, A. et al. (2026) Thermal transport and defect evolution in laser powder bed fused copper and copper-silver alloys. Journal of Alloys and Compounds Communications, 11, 100210.
Publisher
Research Unit
PubMed ID
PubMed Central ID
Embedded videos
Additional Links
Type
Journal article
Language
en
Description
© 2026 The Authors. Published by Elsevier. This is an open access article available under a Creative Commons licence.
The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.1016/j.jacomc.2026.100210
Series/Report no.
ISSN
2950-2845
EISSN
ISBN
ISMN
Gov't Doc #
Sponsors
This work was supported by Innovate UK Knowledge Transfer Partnership (KTP) programme (reference 10020894), a collaboration between the University of Wolverhampton and AceOn Battery Solar Technology Ltd.