Forming accuracy improvement of W-Cu microchannels fabricated by laser powder bed fusion

Republished by Newlife - MIM. All rights belong to the original publisher; see Source below.

Highlights • W-Cu microchannels exhibit larger roundness errors than 316L, with relative deviations more pronounced at smaller radii. • Post-contour scanning significantly improves 316L accuracy, whereas zoned annular scanning is more beneficial for W-Cu. • Poor forming accuracy in W-Cu originates from thermophysical mismatch, liquid-phase separation, and particle adhesion. • Single-track geometric model predicts 316L profiles well, but fails for W-Cu.

Abstract The present work provides a comparative analysis between laser powder bed fusion (LPBF) processed W-Cu composites and 316L stainless steel, focusing on the effects of scanning strategy on the side-surface forming accuracy and mechanisms in LPBF-processed microchannels. Thin-wall structures were fabricated under interlayer rotation angles of 0°, 67°, and 90°. Circular microchannels were first produced using conventional linear hatch scanning, followed by two optimization strategies: post-contour scanning (PCS) and zoned annular scanning (ZAS). Roundness errors were evaluated using the Minimum Zone Circle method, and dimensional predictions were performed using a modified single-track melt-pool geometric model. Compared with 316L, W-Cu microchannels exhibited severe adhesion of unmelted W particles and spheroidized Cu phases, leading to pronounced boundary irregularity. At a designed radius of 500 μm, the mean roundness error of W-Cu was 158.6 ± 8.3 μm, approximately 2.0 times that of 316L at 79.7 ± 9.9 μm. The optimization effectiveness was material dependent. PCS was most effective for 316L, reducing the roundness error to 37.5 ± 2.9 μm, whereas ZAS was more suitable for W-Cu, decreasing the roundness error to 88.2 ± 15.4 μm. The modified geometric model provides good quantitative agreement for 316L microchannels, with an MAE of 0.03270 and an R2of 0.83101, whereas substantially larger deviations remain for W-Cu. The model therefore captures only the overall size-dependent trend for W-Cu and is not suitable for accurate quantitative prediction of this material system.

Source

- sciencedirect.com (2026-08-28) - Original article: Forming accuracy improvement of W-Cu microchannels fabricated by laser powder bed fusion - ScienceDirect - https://sciencedirect.com/science/article/pii/S0263436826004452