Chemical and Chemical-Mechanical Polishing of Surface Roughness on L-PBF/GRCop-42 Cu-Cr-Nb Additive Manufactured 10-GHz RF Structures
Name
Chemical and Chemical-Mechanical Polishing of Surface Roughness on L-PBF GRCop-42 Cu-Cr-Nb Additive Manufactured 10-GHz RF Structures.pdf
Description
Published version
Size
12.6 MB
Format
Adobe PDF
Checksum (MD5)
83ca1aa6a25345940bdb932277915523
Author(s)
Seltzman, AH
Wukitch, SJ
Date Issued
September 30, 2025
Journal
Fusion Science and Technology
Publisher
Taylor & Francis
Citation
Seltzman, A. H., & Wukitch, S. J. (2026). Chemical and Chemical-Mechanical Polishing of Surface Roughness on L-PBF/GRCop-42 Cu-Cr-Nb Additive Manufactured 10-GHz RF Structures. Fusion Science and Technology, 82(1–2), 122–134.
Version
Final published version
Abstract
Laser-based powder bed fusion (L-PBF) allows additive manufacture (AM) of lower hybrid current drive (LHCD) radio-frequency (RF) launchers from Glenn Research Copper, a Cr2Nb precipitation-hardened alloy (GRCop-42) in configurations unachievable with conventional machining. Rough surfaces in AM components increase RF losses and lead to arcing in high-power vacuum RF applications. Chemical polishing, chemical-mechanical polishing, or a combination of both were utilized to planarize the internal surfaces of RF structures, resulting in surface roughness as low as Ra = 0.2 µm. Refinement in polishing techniques now enables GRCop-42 alloys (4 at. % Cr, 2 at. % Nb) to achieve similar surface roughness to GRCop-84 (8 at. % Cr, 4 at. % Nb) and equivalent cavity losses to extruded oxygen-free copper waveguides at 10 GHz.
MIT Department
Massachusetts Institute of Technology. Plasma Science and Fusion Center
Terms of Use
Creative Commons Attribution-NonCommercial-NoDerivatives
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1080/15361055.2025.2540224
