Enhancing the dimensional accuracy and manufacturing limits of laser powder bed fusion through dual-laser hybrid additive-subtractive manufacturing

Laser Powder Bed Fusion (LPBF) is a prominent additive manufacturing technique used for metallic materials. However, the process is often hindered by defects such as powder adhesion, slag formation, and irregularities in the melt pool, which degrade surface quality, dimensional accuracy, and formability. This study achieves hybrid additive-subtractive manufacturing based on picosecond laser processing by coaxially integrating a picosecond pulsed laser into the LPBF scanning system, and explores its effectiveness in improving the quality of LPBF-fabricated components. This hybrid method, blending additive and subtractive manufacturing, was analyzed for its impact on surface quality, manufacturing precision, and micro-dimensional forming capability. Experimental results showed a 67.3 % reduction in side surface roughness, and dimensional accuracy was improved, achieving a minimum groove width of 93.05 ± 8.97 μm compared to 191.97 ± 12.33 μm in conventional LPBF. These findings highlight enhanced surface finish and forming precision, offering a cost-effective pathway for the fabrication of micro-scale structural components.