Super capillary performance of hybrid-structured wicks additively manufactured via laser powder bed fusion

Abstract

The capillary performance coefficient (K/R_eff) is a crucial performance indicator of the wick, a key component of high-performance heat pipes. However, it is difficult to enhance the permeability (K) and capillary pressure ($\Delta P_{\mathrm{cap}}$) at the same time. A wick with channels and porous hybrid structure was fabricated using Laser Powder Bed Fusion (LPBF) to achieve superior capillary performance. The channel structure ensures excellent permeability (K), while the porous structure offers high capillary pressure, which is further enhanced by the corner flow effect. The optimal structure, featuring a 0.6 mm square channel and 70.99 % porosity, achieved an ultra-high capillary performance of 3.24 × 10⁻⁶ m, which is 106.3 % higher than the previously reported best value. This study introduces a novel design concept and preparation method for high-performance heat pipes.