Process and Capillary Performance of High-strength Aluminum Micro-structures Fabricated by Micro Laser Powder Bed Fusion

doi:10.3901/JME.260079

Abstract

Abstract: To address the high-precision and mass-transfer of high-strength aluminum alloy capillary wick structures, this study investigates the printability and capillary performance of micro-featured structures fabricated via conventional laser powder bed fusion (c-LPBF) versus micro laser powder bed fusion (μ-LPBF). The μ-LPBF process achieved a structural resolution limit of ~86 μm, with defect equivalent diameter ranging from 25-40 μm, average defect volume of 9.99×10^-6 mm³, and sphericity of 0.76. These results significantly surpass c-LPBF performance (defect equivalent diameters: 50-100 μm; sphericity: 0.48), demonstrating superior dimensional accuracy and defect suppression capability for sub-200 μm features. Numerical simulation revealed the evolution mechanisms of particle splashing and denudation behavior: Strong metallic vapor plumes of c-LPBF induced powder splashing velocities up to 10 m/s and denudation zone widths of 821-932 μm. In contrast, μ-LPBF’s attenuated vapor disturbance reduced splashing velocities below 5 m/s and narrowed denudation zones to 159-239 μm, markedly enhancing process stability. The μ-LPBF-fabricated structures exhibited enhanced capillary metrics, including a higher capillary pressure-permeability product (ΔP_capK=16.08×10^-8 N) and capillary factor (K/R_eff=1.16 μm), indicating balanced comprehensive mass transfer performance. It provides a theoretical foundation for optimized design and integrated manufacturing of thermal management structures.

Key words: laser additive manufacturing, micro laser powder bed fusion, high-strength aluminum alloy, capillary structure

CLC Number:

V261

LIU He, GU Dongdong, LI Linxuan, PEI Bin, ZHOU Youyou. Process and Capillary Performance of High-strength Aluminum Micro-structures Fabricated by Micro Laser Powder Bed Fusion[J]. Journal of Mechanical Engineering, 2026, 62(3): 190-202.

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