Resolution and geometric limitations in laser powder bed fusion additively manufactured GRCop-84 structures for a lower hybrid current drive launcher

Laser Powder Bed Fusion (L-PBF), also known as Selective Laser Melting (TM) (SLM (TM)), allows additive manufacture of lower hybrid current drive (LHCD) Radio Frequency (RF) launchers from a new material, Glenn Research Copper 84 (GRCop-84), a Cr2Nb (8 at. % Cr, 4 at. % Nb) precipitation hardened alloy, in configurations unachievable with conventional machining. The resolution and geometric limitations are tested to explore the limitations of L-PBF printing of GRCop-84. Printing holes in the vertical and horizontal direction are examined to determine the minimum cooling channel diameter. Internal stress limits the minimum thickness of vertical walls and septa to 1 mm, thinner walls warp during printing. Roughness is minimized on vertical surfaces and increases on both upper and lower surfaces as angle increases. Accuracy within 40 mu m is typical on well supported structures.

Automated summary

When using Laser Powder Bed Fusion (L-PBF) to manufacture GRCop-84, the minimum thickness of vertical walls and septa is 1 mm, with thinner walls warping during printing. Additionally, roughness increases on both upper and lower surfaces as the angle increases.