Enhanced Pool Boiling via Binder Jetting 3D-Printed Porous Copper Structures: CHF and HTC Investigation

Escalating heat flux densities in high-performance electronics necessitate superior thermal management. Pool boiling heat transfer, offering high heat removal capacity, was enhanced using binder jetting 3D-printed (BJ3DP) porous copper structures. Leveraging BJ3DP to create complex porous copper structures without chemical treatments—thereby enabling reliable utilization of phenomena like capillarity—this study enhanced pool boiling heat transfer. Therefore, in this study, three types of porous copper structures—Large Lattice, Small Lattice, and Staggered—were fabricated on pure copper substrates and tested via pool boiling of de-ionized and de-gassed water at atmospheric pressure. Compared to a plain polished copper surface (plain surface), which exhibited a critical heat flux (CHF) of 782 kW/m² at a wall superheat of 18 K, the 3D-printed porous copper surfaces (sinterd plain surface) showed significantly improved CHF performance. In particular, the Staggered surface achieved a CHF of 2289 kW/m²—an enhancement of 193%—at a wall superheat of 25.9 K. Although CHF was not reached for the Large Lattice and Small Lattice structures, they attained maximum heat fluxes of 2071 kW/m² (165% higher at a wall superheat of 53.9 K) and 2291 kW/m² (193% higher at a wall superheat of 38.6 K), respectively. These improvements are attributed to the formation of distinct vapor–liquid pathways within the porous structures, promoting rewetting of the heated surface through capillary action. This mechanism supports a highly efficient, self-sustaining boiling configuration. The porous surfaces also demonstrated a higher heat transfer coefficient (HTC), particularly at lower heat fluxes (≤750 kW/m²). High-speed digital camera visualization provided further insights into the boiling phenomena. Overall, the findings demonstrate that these BJ3DP structured surfaces, through optimized liquid-vapor pathways and capillary-enhanced rewetting, offer significantly superior heat transfer performance compared to smooth surfaces, highlighting their potential for advanced thermal management.